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Year: 2019 (page 1 of 2)

How To Create A Completely Free WordPress Website With Hosting And Domain

You may have listened. You can not make a free website or get the hosting without money, but you can.

In this post, I am going to tell you the 100% true and working method of getting hosting for You can have a domain name, not a subdomain.

So let us explore how it can happen.

Step 1: Getting A free domain name:

As we know that there are some of the free domain names such as .ga or .cf available in the market. These domains are high-level domains. You can use one of these on your website.

Freenom is a website which is providing these free domains in their website.

  • Sign in or create a new account in freenom.
  • By clicking the sign-in button you will reach to the sign-in options. You can sign in through your email and password or you can use an alternative like Facebook or Google sign in.
Sign in with facebook or gmail in freenom

sign in options

  • After signing in you will reach to the main page of Freenom.
  • Click on services.
  • Click on Register A New Domain.
Register new domain name

Register new domain name

  • After clicking you will reach to a new page Check Domain.
  • Here you have to write your favourite domain name which you want for your site.
  • Check if it is available.
Write your desired domain name

Write your desired domain name

  • After adding your domain name and clicking you will see which domain name is available for free.
  • I put askzaib in search and i got a lot of domains, which are as under;
Available domains 1

Available domains 1

Available domains 2

available domains 2

Here I think .ga is a well-reputed domain name rather then .tk etc. It is upon you which domain name will you use. I used for the demo purpose.

  • Now you have to click on check out for further proceeding.
Check Out

Check Out

  • When you click to the check out you will reach to the page having many options but you just have to increase the domain expiry date. In default it is selected as 3 months you can increase it to  1 year.
  • Click Continue.
Increasing the expiry date of domain

Increasing the expiry date of domain

  • Clicking continues you will reach the page where you have to put some info.
  • After filling the form tick on the agreement.
  • Click Complete Order.
Basic domain info

Basic domain info

After completing this check out now you have to click on services and then My Domains.

  • You will reach to the domain page.
  • Here you have to click the Manage Domain option in front of the domain.
Managing domain

Managing domain

  • Click On Managing Tools.
  • Click On nameservers.
nameserver changing

nameserver changing

  • By clicking name server you will reach to nameserver page.
  • Basically, the default nameserver is set.
  • Change it to Use Custom Name Server
Custom nameserver 2

Custom nameserver 2

you’ll need to enter the following nameservers provided by InfinityFree:



Click on Change Nameservers to save your changes.

Signing up with infinityfree unlimited hosting:

See the above picture, here we have 5 places for nameservers, but here we do not have any server. We have to get a server and then giving its nameservers here.

For getting the hosting we have to go to InfinityFree. This hosting server provider is one of the cheapest hosting providers. go to .

Siign up for account

Siign up for account

  • Sign Up for a new account.
  • Clicking sign up you will reach to sign up form.
  • Fill the form and continue.
Fill this form and continue

Fill this form and continue

  • After creating the account you will reach to your Dashboard.
Dashboard of InfinityFree

Dashboard of InfinityFree

  • Write your domain name in the place of domain given by InfinityFree.
  • Solve the ReCaptcha.
  • Click On Create Account.
Putting information for account

Putting information for account

After clicking CREATE ACCOUNT it sometimes takes time, so don’t worry if it does not work in the first attempt try clicking again.

Now your Control Panel is created

Click on the Open Control Panel.

Installing WordPress:

The first thing you need to do is log in to your current Account Cpanel, you can do this in two ways.

First, is by clicking on the Control Panel button directly from the Accounts page.

Note: Infinityfree allows you to have a maximum of three domain names for a single account. To add more websites, you need to upgrade to their premium hosting services.

Second, is by clicking on the Manage button which will open in a new tab. Then, you need to click on the Control Panel button.

Both of these work the same way. This will open in a new tab/window and automatically signed you in to your Cpanel area.

Once logged in, go to Softaculous Apps Installer under the Software section.


After clicking the Softaculous you will reach a page of different software.

There are so many software, if you want to use another you can also but choose WordPress it is the most reliable and easiest platform.

When you click the WordPress you will reach to the installation page. Click Install Now.

When you click the Install Now button you will reach to another page. I recommend you to not change anything if you are new. You just have to change;

  • Username and Password,  because a simple username or password can be a danger for your site. It can be hacked easily.
  • Site Name, which is the name of your newly built site you have to change it according to your site name just our is Ask Zaib.
  • Site Description,  it is a piece of information about your site change it in accordance with your site.
  • Click Install.

Hurray, you have a new and beautiful website for free.


So you have built your site, if you are facing any problem in this trick comment below I am here to help you.

How To Create A Blogspot Website Easily?

Website? Nowadays everyone is interested in creating a website for his business or for making money online. But creating a website demand money from you. Blogger is a platform by Google which is free and you do not need to buy a hosting plan for blogger. If you are interested you just have to buy a domain name.

Today I will crack the steps which you have to follow to make your website.

Step 1: Making a Gmail ID:

As we know that google now has closed its service of Google+, so the steps for Blogger are changed a little. You have to create an email account in Gmail.

Step 2: Create the Blog:

  • You have to go on
  • Sign-in into blogger using the Gmail account you have created.
To Blogger

Sign In Photo

  • You will reach to the Blogger Dashboard. Now just click on Create New Blog. See Pic Below;
Creating Blog

Create Blog

After Clicking on create a blog, you will return to this page;

  • Choose your Blog’s Name.
  • Choose a URL for your blog. But remember it must be available so you will see the tick in front of it.
  • Choose a basic theme you like.
  • Click Create Blog!.

You May Like: How To Create A Completely Free WordPress Website With Hosting And Domain

Step 3: Write Your First Post

When you follow the above steps, you will create your Blog. Now you need to know about the posting in your Blog.

You will find the New Post button under the Posts tab.

New Post Picture

    New Post
  • Click On New Post.
Post Title Demo

Post Title

  • Write your Post Title.
  • Write Your Post Description.

After these steps, you have to add some labels in your post. Labels are like categories. These labels can be used for making different categories in your site or these will help to make the menu of your site.

Adding Labels to your blogger website

Adding labels

  • Insert Labels using Commas between them such as (demo, new post, amazing)
  • Click on done button.


Publish Post in your website

Publish Post

  • Click On Save to save your post in drafts.
  • Click on the preview to check how the post is looking before Publishing, so may change anything you want to.
  • Publish the post.

When you click on Publish button you will be returned to your Posts Page.

Reurn to post page of your website

Return to post page

Here in the Post Page, now you can see your recent uploaded post.  You can see it live if you click on it there come 3 options.

  1. EDIT: By which you can edit the post.
  2. View: So, clicking which you can see the post view.
  3. Delete:  You can delete the post.

If you click the View option you will see how your post looks like.

Post View Of your website

Post View

You can Also see the Blog View if you go to your Dashboard, Click  On view blog.

View Your Website

View Blog


Biology is the study of living things. It is a branch of science and like other sciences, it is a way of understanding nature. Biologists deal with the living part of nature and with the non-living things which affect the living things in any way. they strive to understand, explain, integrate and describe the natural world of living things. The literal meaning of biology is the study of life.

It is very difficult to define life. There are certain aspects of life that lie beyond the scope of the science of biology like the answers to the questions: what is the meaning of life? Why should there be life? These are the questions not usually taken up by Biologists and are left to philosophers and theologians. Biologists mainly deal with matters relating to how life works.

Life, for biologists, is a set of characteristics that distinguish living organisms from non-living objects (including dead organisms). Living organisms are highly organized, complex entities; are composed of one or more cells; contain the genetic program of their characteristics;

  •  Acquire and use energy.
  • Can carry out and control numerous chemical reactions.
  • Grow in size.
  • Maintain a fairly constant internal environment.
  • Produce offspring similar to themselves; respond to changes in their environment.

Any object processing all these characteristics simultaneously can be declared as a living thing and in an object for biological studies.

The science of biology is a very wide based study. It includes every aspect of a living thing. Volumes and volumes of information are available under this major head. It is but natural to divide the science into quite a number of branches for our convenience of comprehending and studying biology.

You are surely familiar, at this stage, with Ecology, Embryology, Physiology, Morphology (external Morphology or Anatomy), Paleontology, Histology, Evolution, Genetics, Zoo-geography etc. These are branches of biology which deal with environmental relations, development, functions, structure, form and internal gross structure, fossil, tissues, ancestral history, heredity and distribution of animals in nature, respectively. In addition to these branches, there are a number of other branches of biology such as Molecular Biology, Microbiology, Marine Biology, Environmental Biology, Freshwater Biology, Parasitology, Human Biology, Social Biology, Biotechnology, etc.

Molecular Biology:

Molecular biology is a branch of biology which deals with the structure of organisms, the cells and their organelles at the molecular level.

Environmental Biology:

Environmental Biology is the study of organisms in relation to their environment. This includes
the interaction between the organism and their inorganic and organic environment, especially as it
relates to human activities.


This is the study of microorganisms which include Bacteria, Viruses, Protozoa and microscopic
algae and fungi.

Freshwater Biology:

This branch of biology deals with the organisms living in freshwater bodies i.e., rivers, lakes etc and physical and chemical parameters of these water bodies.


Marine Biology:

This is the study of life in seas and oceans. This includes the study of the marine life and the physical
and chemical characteristics of the sea acting as factors for marine life.


This is the branch of biology which deals with the study of parasites. The structure, mode of transmission, life histories and host-parasite relationships are studied in parasitology.

Human Biology

It deals with the study of man. This includes form and structure, function, histology, anatomy, morphology, evolution, genetics, cell biology and ecological studies etc. of human beings.

Social Biology

This is the branch of biology which deals with the study of social behaviour and communal life of human beings.


It deals with the use of living organisms, systems or processes in manufacturing and service industries.


Hundreds of chemical reactions are involved in maintaining the life of even the simplest organism. In view of this, it is something of a surprise to find that of the 92 naturally occurring chemical elements, only 16 are commonly used in forming the chemical compounds from which living organisms
are made. These 16 elements and a few others which occur in a particular organism are called elements.
In the human body, only six bio-elements account for 99%of the total mass.

The fact that the same 16 chemical elements occur in all organisms, and the fact that their properties differ from those in the non-living world, shows that bio-elements have special properties which make them particularly appropriate as the basis for life.

The biological organization is not simple. It has a high degree of complexity because of which the living organisms are able to carry out a number of processes (some very complicated) which distinguish them from the non-living things. A living thing has built-in regulatory mechanisms which interact with the environment to sustain its structural and functional integrity.

A living thing is, therefore, composed of highly structured living substance or protoplasm. In order to understand the various phenomena of life, biologists for their convenience, study the biological organization at different levels starting from the very basic level of subatomic and atomic particles to the organism itself and beyond which the study of community, population and the entire world are included. The biological organization can be divided into the following levels,

Levels Of Organization

Atomic & Subatomic Levels:

All living and nonliving matter is formed of simple units called atoms and subatomic particles such as protons, electrons & neutrons.

Molecular Level:

In organisms elements usually, do not occur in isolated forms. The atoms of different elements combine with each other through ionic or covalent bonding to produce compounds. This stable form is called a molecule. Hydrogen, carbon, oxygen, nitrogen, phosphorous and Ca are the most common atoms found in biological molecules. The different types of bonding arrangement permit biological molecules to be constructed in great variety and complexity. These may be micro-molecules with low molecular weight like C02, H20 etc. or macro-molecules with high molecular weights e.g. starch, proteins etc.

Biological world has two types of molecules: organic and inorganic. An organic molecule is any molecule containing both carbon and hydrogen. Inorganic molecules do not include carbon and hydrogen together in a molecule.

An organism is usually formed by an enormous number of micro and macromolecules of hundreds of diferent types. Some most important and abundant organic molecules in organisms are glucose, amino acids, fatty acids, glycerol, nucleotide-like ATP, ADP, AMP etc.

Organelles & Cell:

A different and enormous number of macromolecules and macromolecules arrange themselves in a particular way to form cells and their organelles. In the case of simple organisms like bacteria and most protists, the entire organism consists of a single cell. In most fungi, plants and animals, the organism may consist of up to trillions of cells.

Numerous sub-cellular structures like mitochondria, Golgi-complex, endoplasmic reticulum, ribosomes etc have been studied for their structure and function. It has become clear that the functions of the cells are accomplished by these specialised structures comparable to the organs of the body. These structures are called organelles.

The arrangement of the organelles speaks of the division of labour within the cell. The prokaryotes have only a limited number and type of organelles in their cytoplasm. Eukaryotes are rich in number and kinds of membranous organelles. A cell membrane is however present in all cells whether prokaryotic or eukaryotic.

Tissue Level:

In multicellular animals and plants, groups of similar cells are organized into loose sheets or bundles performing similar functions; these are called tissues. Each tissue has a particular function in the life of the organism e.g. muscle tissue, glandular tissue, xylem tissue, phloem tissue etc. They are specialized for contraction (movement), secretion, conducting water and for translocation of sugar, proteins etc.

Organ & System:

Different tissues having related functions, assemble together in a structure to carry out its function with great efficiency. Such structures are called organs and they are specialized to perform particular functions. For example, stomach which is an organ has a function of food digestion (protein part), has a secretory epithelium which secretes the gastric juice, and muscular tissue (smooth) for contracting the walls of the stomach and mixing the food with the enzyme thoroughly and moving the food to the posterior end. The formation of organs also has a selective value because this leads to an efficient accomplishment of their functions both qualitatively and quantitatively. In animals,

organ formation is far more complex and denied. Organs are part of organ systems where total functions involved in one process or phenomenon are carried out. The organ level of organization is much less definite in plants than it is in animals. At the most, we might distinguish roots, stems, leaves and reproductive structures. Clear cut functions, the distinguishing features, can be assigned to each of these structures. Roots are involved in anchoring the plant, storage of food and procuring water and minerals. The shoot supports the entire plant while the leaves are primary organs for food manufacture. Flowers or other reproductive structures are involved in producing the next generation (reproduction). The complexity of the organ systems of animals is associated with a far greater range of functions
and activities that are found in plants.

Individual (Whole Organism)

Various organs in plants and various organ systems in animals are assembled together to form an individual – the whole organism. The whole organism has its individuality as far as its characteristics are concerned. It is diferent from other members of the same species in certain respects. The various functions, processes, activities of an organism are coordinated. In an animal, all the systems work in coordination with each other. For instance, if a man is engaged in continuous and hard exercise, not only his muscles are working but there is an increase in the rate of respiration and heartbeat to supply the muscles with increased oxygen and food which they need for continuous exercise. In animals, the coordination is achieved by means of the nervous system and endocrine system, whereas in plants only long term regulation of activities is brought about by hormones.

Organism works as a whole and it interacts and responds to the environmental changes as a whole.


A population is a group of living organisms of the same species located in the same place at the same time. Examples are the number of rats in a field of rice, the number of students in your biology class, or the human population in a city.

The population is a higher level of biological organization than organism (whole) because here a group of organisms of the same species is involved. This level of organization has its own attributes which come into being by living together of a group of organisms of the same species.

Some of these attributes are gene frequency, gene low, age distribution, population density, population pressure etc. All these are new parameters which have appeared due to the population of an organism. You will study them in detail in population ecology,


Populations of different species (plants and animals) living in the same habitat form a community. Communities are dynamic collections of organisms, in which one population may increase and others may decrease due to fluctuation in abiotic factors. Some communities are complex and well interrelated, other communities may be simple. In a simple community, any change can have drastic and long-lasting effects.

The foregoing account makes it clear that an organism can be studied at different levels of the organization. It can be studied at subatomic, atomic, molecular, macromolecular, organelle, cell, tissue, organ and organ system level. We can also look at it as an individual, as a part of the population of similar individuals, as a part of a community that includes other populations and a part of the community of an ecosystem which includes abiotic factors as well as living organisms, Fig. 1
The organisms, interaction can take many shapes. It may be predation, parasitism, commensalism, mutualism and competition.

Living World in Space:

Living world of today is enormous in size. It has been reproducing and evolving since the time of its origin on this planet. Today almost all parts of the world abound in living organisms. The distribution of organisms in space can be studied through biomes.

A biome is a large regional community primarily determined by climate. It has been found that the major type of plant determines the other kind of plants and animals. These biomes have, therefore, been named after the type of major plants or major feature of the ecosystem. The major biomes of the world you will study in the chapter of ecology.


The time of origin of life on this planet, various organisms were evolved and dominated this planet during various periods of geological time chart. This has been found by the evidence obtained from the discovery and study of fossils which allows biologists to place organisms in a time sequence. As geological time passes and new layers of sediments are laid down, the older organisms should be in the deeper layer, provided the sequence of the layers has not been disturbed.

It is possible to date/age rocks by comparing the amounts of certain radioactive isotopes they contain. The older sediment layers have less of these specific radioactive isotopes than the younger layers. A comparison of the layers gives an indication of the relative age of the fossils found in the rocks. The fossils found in the same layer must have been alive during the same geological period.

You can have an idea about the temporal distribution of various forms of life both plants and
animals in the various geological periods ( fig.1.3)

Want to learn more about LIVING WORLD IN TIME? Click here


The science of biology has been helping mankind in many ways in increasing food production; in combating diseases and in protecting and conserving the environment. Biological advances in the field of food and health have resulted in a high standard of living.

Plant production has been tremendously increased by improving existing varieties and developing new high-yield and disease – resistant varieties of plants and animals used as food.

Plant and animal breeders have developed, through selective breeding, using the principles of genetics, new better varieties of wheat, rice, corn, chicken, cow and sheep. Poultry breeders have developed broilers for getting quick and cheap white meat. Genes for disease resistance and other desirable characters are introduced into the plant, using the techniques of genetic engineering. Such transgenic plants (plants having foreign DNA incorporated into their cells) can be propagated by cloning (production of genetically identical copies of organisms/cells by asexual reproduction)
using special techniques, tissue culture techniques.

Plant pathogenic fungi and insect pests of crops which weaken the plants. So, Use of these chemicals poses toxicity problems for human beings as well as environmental pollution. There are chances of insects becoming resistant to the effect of these chemicals. Biological control (control by some living organisms) eliminates all such hazards.  That compete with or even eat them up. An aphid that attacks the walnut tree is being controlled biologically by a wasp that parasites this aphid. Learn More Here


The industrialization has helped mankind to raise the standard of living. It has destroyed our environment. These effluents frequently contain the sizeable amount of certain very toxic even carcinogenic materials. Heavy metals like lead from automobiles, chromium from tanneries, are playing havoc to human health. Environmental pollution has reached an alarming level in some countries.

Biology has helped mankind in attracting attention to this problem and the biologists are striving to end the solution to set this environment right wherever it has deteriorated: Biologists have already asked for the treatment of industrial effluents to be made obligatory. Similarly, Several ways of bio-remediation (removal or degradation of environmental pollutants or toxic materials by living organisms) are also under investigation. For example, algae reduce the pollution of heavy metals in the environment. Biologists are also working out the list of endangered species of plants and animals.

They have stressed the needs for their protection. Environmental pollution is a national problem in Pakistan.  The Pollution is spreading in rivers and canals with the mixing of city sewage and industrial wastes. The life in the fresh water of Pakistan is towards decline.  We need to take protective measures as early as possible. In cities, the silencer from cars is adding lead to the environment. There is a need for lead-free petrol to reduce pollution.



The science of biology has been helping mankind in many ways in increasing food production; in combating diseases and in protecting and conserving environment. Biological advances in the field of food and health have resulted in high standard of living.

Plant production has been tremendously increased by improving existing varieties and developing new high-yield and disease – resistant varieties of plants and animals used as food.

Plant and animal breeders have developed, through selective breeding, using the principles of genetics, new better varieties of wheat, rice, corn, chicken, cow and sheep. Poultry breeders have developed broilers for getting quick and cheap white meat. Genes for disease resistance and other desirable characters are introduced into plant, using the techniques of genetic engineering. Such transgenic plants (plants having foreign DNA incorporated into their cells) can be propagated by cloning (production of genetically identical copies of organisms/cells by asexual reproduction)
using special techniques such as tissue culture techniques etc. Plant pathogenic fungi and insect pests of crops which weaken the plants and reduce the yield had traditionally been controlled by using chemical fungicides and insecticides (pesticides). Use of these chemicals poses toxicity problems for human beings as well as environmental pollution. Moreover, there are chances of insects becoming resistant to the effect of these chemicals. Biological control (control by some living organisms) eliminates all such hazards. In biological control, pests are destroyed by using some living organisms that compete with or even eat them up. An aphid that attacks walnut tree is being controlled biologically by a wasp that parasites this aphid.

Even some bacteria are being used as bio-pesticides. Effective control of a particular disastrous disease, or all the common diseases of a plant can be achieved by using all relevant, appropriate methods of disease control. Such an approach of disease control is called “integrated disease management”.

Soil is a complex medium. It is almost impossible to conduct experiments on nutrient requirements of plants by growing them in soil. Hydroponic culture technique is used to test whether a certain nutrient is essential for plant or not. In this technique the plants are grown in aerated water to which nutrient mineral salts have been added. Hydroponic farming, however, is yet not feasible. Astronauts may use it for growing vegetables.

Different techniques of food preservation have been developed for protecting food from spoilage and for its use and transport over long distance without damaging its quality. One of these is pasteurization, developed by Louis Pasteur. It is being widely used for preservation of milk and milk products.

Disease Control :

There has been fantastic progress in the area of health and disease control. Three-pronged actions are usually taken against various diseases.

  1. Preventive measures
  2. Vaccination/Immunization
  3. Drug treatment/Gene therapy

Preventive measures

The advances in biology sciences have provided us with information about the causative agents of the diseases and their mode of transmission. For instance the AIDS (Acquired Immune Deficiency Syndrome) is caused by HIV (human immune deficiency virus) and it spreads through free sexual contact, through blood transfusion, by using contaminated syringes or surgical instruments etc. Therefore, doctors advise us to take precautions on these fronts so that we do not contract the disease, which is at present incurable. Similarly, hepatitis is caused by H.virus which is spread through blood transfusion by using contaminated syringes and surgical instruments etc. In this case also doctors advise us to be careful and avoid the point of contact.

Vaccination / Immunization

Many diseases such as polio, whooping cough, measles, mumps etc can easily be controlled by vaccination or “shots”.

Edward Jenner (a Biology Expert) first developed the technique of vaccination in 1796, cowpox pus is known as vacca (from Latin vacca=cow). From this word evolved the present term vaccination and vaccine. You will learn more about vaccination in chapter 6. Since then, inoculation or vaccination is carried out to make the people immune from viral or
bacterial epidemics or, for some diseases the individuals are vaccinated in their early life to make them immune to those diseases. It is claimed that small pox has been totally eliminated from the world by using this method. Scientists are making continuous efforts to develop a vaccine against other diseases. Even vaccine against AIDS is being administered in humans on experimental basis.

Drug treatment / Gene therapy

If a person becomes sick with disease, he is subjected to the action of antibiotics which can kill bacteria. The antibiotics are, however, useful in bacterial disease and that only when bacteria have not developed resistance to antibiotics. In cancer, radiotherapy and chemotherapy are also used. In radiotherapy, the cancerous part is exposed to short wave radiations from the radioactive material repeatedly at regular intervals. In Pakistan there are several centres which are carrying out radiotherapy to control cancer. Chemotherapy consists of administrating certain anticancer chemicals to the patients at regular intervals. These chemicals may kill both cancerous and normal

Recently a new technique has been developed to repair defective genes. This consists of isolating the normal gene and inserting it into the host through bone marrow cells. This is called gene therapy.

Combating disease utilizing all methods as and when required and ensuring participation of the community in this programme is known as integrated disease management. This requires awareness of the community about the severity of the problem, its causes and its remedies. This is a very effective programme for elimination and control of dangerous diseases from the human society.

Cloning: In Biology , cloning is a technology for achieving eugenic aims. A clone is denied as a cell or individual and all its asexually produced offspring. All members of a clone are genetically identical except when a mutation occurs.

Generally, no normal animal reproduces naturally by cloning. Several insects and many plants do, in some circumstances whereas few do so regularly. In 1997 scientists in Scotland succeeded in cloning a sheep. Other mammalian species (mice and cows) have since been cloned. In this procedure, the nucleus from a fertilized egg is removed and a nucleus from a cell of a fully developed individual is inserted in its place. The altered zygote is then implanted in a suitable womb where it completes its development. The new individual formed in this way is a genetically identical clone of the individual whose nucleus was used. Thus cloning
could make multiple copies of the desired genotype.

Another type of cloning is the division of a single egg or early embryo into one or more separate embryos. This is the same process that normally creates identical twins. Offspring from this type of cloning are genetically identical but carry chromosomes from each of the two parents. This type of cloning has already been used to produce genetically identical cattle and other farm animals.

Man is likely to adopt cloning techniques for commercial production of valuable animals of known pedigree such as horses etc.

At some places, scientists in biology are making attempts to clone human embryo which they believe can serve as a transplant donor. There is a lot of controversy on this issue as to whether human cloning should be attempted or not.





Time of origin of life on this planet, various organisms were evolved and dominated this planet during various periods of geological time chart. This has been found by the evidence obtained from the discovery and study of fossils which allows biologists to place organisms in a time sequence. As geological time passes and new layers of sediments are laid down, the older organisms should be in deeper layer, provided the sequence of the layers has not been disturbed.

In addition it is possible to date/age rocks by comparing the amounts of certain radioactive isotopes they contain. The older sediment layers have less of these specific radioactive isotopes than the younger layers. A comparison of the layers gives an indication of the relative age of the fossils found in the rocks. Therefore, the fossils found in the same layer must have been alive during the same geological period.

You can have an idea about the temporal distribution of various forms of life both plants and
animals in the various geological periods ( fig.1.3)

Phyletic Lineage Of Time

When we look at the biodiversity (the number and variety of species in a place), we ind that there are nearly 2,500,000 species of organisms, currently known to science. More than half of these are insects (53.1%) and another 17.6 % are vascular plants. Animals other than insects are 19.9 % species) and 9.4 % are fungi, algae, protozoa, and various prokaryotes.
This list is far from being complete. Various careful estimates put the total number of species between 5 and 30 millions. Out of these only 2.5 million species have been identified so far.

The life today has come into existence through Phyletic lineages or evolving populations of the organisms living in the remote past. Evolutionary change often produces new species and then increases biodiversity. A phyletic lineage is an unbroken series of species arranged in ancestor to descendant sequence with each later species having evolved from one that immediately proceeded it. If we had a complete record of the history of life on this planet, every lineage would extend back in time to the common origin of all early life. We lack that record because many soft bodied organisms of the past had not left their preserved record as fossils.

Biological Method:

Science is a systematized knowledge. Like other sciences, biological sciences also have a set methodology. It is based on experimental inquiry. It always begins with chance observation. Observations are made with ive senses viz, vision, hearing, smell, taste and touch, depending upon their functional ability. Observations can both be qualitative and quantitative. Quantitative observations have accuracy over qualitative as in the former variables are measurable and are recorded in terms of numbers. An observer organizes observations into data form and gives a statement as per experience and background knowledge of the event. This statement is the hypothesis, which is tentative explanation of observations.

At this stage you should look at the ways of devising hypothesis. There are two ways of formulating
hypothesis. A hypothesis can be the result of deductive reasoning or it can be the consequence of
inductive reasoning.

Deductive reasoning moves from the general to the species. It involves drawing species conclusion from some general principle/assumptions. Deductive logic of “if ……. then” is frequently used to frame testable hypothesis. For example, if we accept that all birds have wings (premise #1), and that sparrows are birds (premise # 2), then we conclude that sparrows have wings. If all green plants require sunlight for photosynthesis, then any green plant when placed in dark would not synthesize glucose, the end product of photosynthesis. The other way of reasoning used in the formulation of hypothesis is inductive reasoning which is reasoning from the species to the general. It begins with specific observations, and leads to the formation of general principle. For instance, if we know that sparrows have wings and are birds, and we know that eagle, parrot, hawk, crow are birds, then we induce (draw conclusion) that all birds have wings. The science also, therefore, uses inductive methods to generalize from specific events.

In fact sometimes scientists also use other ways to form a hypothesis, which may include

  1. Intuition or imagination
  2. Aesthetic preference
  3. Religious or philosophical ideas
  4. Comparison and analogy with other processes
  5. Discovery of one thing while looking for some other thing.

These ways can also sometimes form basis for scientific hypothesis. Hypotheses as you already know, are subjected to rigorous testing.

Repeated exposure of a hypothesis to possible falsification increases scientist’s confidence in the
hypothesis when it is not falsified. Any hypothesis that is tested again and again without ever being
falsified is considered well supported and is generally accepted. This may be used as the basis for
formulating further hypothesis. So there is soon a series of hypotheses supported by the results of
many tests which is then called a theory. A good theory is predictive and has explanatory power.
One of the most important features of a good theory is that it may suggest new and diferent
hypotheses. A theory of this kind is called productive.

time picture

However even in the case of productive theory the testing goes on. In fact many scientists take it as a challenge and exert even greater efforts to disprove the theory. If a theory survives this skeptical approach and continues to be supported by experimental evidence, it becomes a scientific law. A scientific law is a uniform or constant fact of nature, it is virtually an irrefutable theory. Biology is short in-laws because of the elusive nature of life.

Examples of biological laws are Hardy-Weinberg law and Mendel’s laws of inheritance. You will learn about them in later chapters. You can see that laws are even more general than theories and afford answers to even more complex questions, therefore there are relatively a few laws in biology.

Coordination and Control Part 1

The tissues and organs in the bodies of multicellular organisms do not work independently of each other. They work together performing their many tasks as the needs of the whole body. This means that these activities are coordinated. Coordination also enables the organism to respond to happenings in the world around it.
One familiar example of coordination is the way in which muscles work together during movement. When a boy runs to catch a ball, he uses hundreds of muscles to move his arms, legs and back. His nervous system uses information from his sense organs and coordinates these muscles. Due to this coordination, the muscles contract in the correct sequence, power and length of time. But that is not all. Such activities involve many other kinds of coordination. For example breathing and heartbeat rates are increased blood pressure is adjusted, and extra heat is removed fast from the body.
How does it happen? Life activities are controlled and coordinated i.e. body works as one unit, in which its different organs and systems cooperate and work in harmony with each other.

When we are writing something, our hands and fingers work in collaboration with our muscles, eyes, thoughts etc. and then very intricate movements result.

Types Of Coordination:

There are two types of coordination in organisms:

  1.  Nervous coordination brought about by nervous system and
  2. Chemical coordination brought about by endocrine system.
    Animals have both the nervous and chemical coordination systems in their bodies while plants and
    other organisms have only chemical coordination.

Coordinated Action:

A coordinated action has five components;

i- Stimuli:

What happens when we touch a snail? We might have seen the flowers of sunflower plant moving towards the sun. What could be the reason for all this? Touch, light etc. are factors that can bring about certain responses in living organisms. These factors are called stimuli. We can define a stimulus as any change in environment (external and internal), which can provoke a response in organism. More examples of stimuli are heat, cold, pressure, sound waves, presence of chemicals, microbial infections etc.

ii- Receptors:

Stimuli are detected by special organs, tissues or cells of body. For example sound waves are detected by ears, light is detected by eyes, chemicals in air are detected by nose and so on. The organs, tissues or cells which are specifically built to detect particular type of stimuli are called receptors


iii- Coordinators:

These are the organs that receive information from receptors and send messages to particular organs for proper action. In nervous coordination, brain and spinal cord are coordinators. They receive information and send messages through neurons in the form of nerve impulses. On the other hand, in chemical coordination, various endocrine glands play the role of coordinators. They receive information in the form of various chemicals and send messages by secreting particular hormones in blood.

iv- Effectors:

These are the parts of body which receive messages from coordinators and produce particular
responses. In nervous coordination, neurons carry messages from coordinators (brain and
spinal cord) to muscles and glands, which act as effectors. In chemical coordination, particular
hormones carry messages from coordinators (endocrine glands) to particular target tissues,
which act as effectors. For some hormones, nephrons act as effectors. Similarly, bones and liver
act as effectors for many hormones.

v- Response

On receiving the message from coordinators, the effector performs action. This action is called response. For example, pulling our hand away from something very hot and the movement of the flower of sunflower towards light are responses. Usually, nervous coordination produces immediate but short-living responses while chemical coordination produces slow but long-living responses.

Human Nervous System:

We have understood the basic model of the working of nervous system. The nervous system in man and in other higher animals is composed of two major components i.e. central nervous system and peripheral nervous system.

Central nervous system comprises of coordinators i.e. brain and spinal cord while peripheral nervous system consists of nerves that arise from central nervous system and spread in different parts of body. All these components are made of neurons. Now we will first examine the structure and types of neuron and then we will go to the divisions of nervous system.

Nerve cell or Neuron:

Nerve cell or neuron is the unit of the nervous system. The human nervous system consists of billions of neurons plus supporting (neuroglial) cells. Neurons are specialized cells that are able to conduct nerve impulses from receptors to coordinators and from coordinators to effectors. In this way they communicate with each other and with other types of body cells. The nucleus and most of the cytoplasm of a neuron is located in its cell body. Different processes extend out from cell body. These are called dendrites and axons. Dendrites conduct impulses toward cell body and axons conduct impulses away from cell body.

Schwann cells are special neuroglial cells located at regular intervals along axons. In some neurons, Schwann cells secrete a fatty layer called myelin sheath, over axons. Between the areas of myelin on an axon, there are nonmyelinated points, called the nodes of Ranvier. Myelin sheath is an insulator so the membrane coated with this sheath does not conduct nerve impulse. In such impulses are called saltatory (‘jumping’) impulses. This increases the speed of nerve impulse.

On the basis of their functions, neurons are of three types;

1. Sensory neurons conduct sensory information (nerve impulse) from receptors towards the CNS. Sensory neurons
have one dendrite and one axon.
2. Interneurons form brain and spinal cord. They receive information, interpret them and stimulate motor neurons.
They have many dendrites and axons.
3. Motor neurons carry information from interneurons to muscle or glands (effectors). They have many dendrites but only one axon.


A nerve means the union of several axons that are enveloped by a covering made of lipid. Based on the property of axons, the nerves are classified into three types.

  1. Sensory nerves contain the axons of sensory neurons only.
  2. Motor nerves contain the axons of motor neurons only.
  3.  Mixed nerves contain the axons of both i.e sensory and motor neurons.

Divisions of the Nervous System:

The details of the central and peripheral nervous systems are given below.

Central nervous system:

The central nervous system consists of brain and spinal cord.

A- Brain

In animals, all life activities are under the control of brain. The structure of brain is suitable to perform this function. Brain is situated inside a bony cranium (part of skull). Inside cranium, brain is covered by three layers called meninges. Meninges protect brain and also provide nutrients and oxygen to brain tissue through their capillaries.
The brain contains fluid-filled ventricles that are continuous with the central canal of spinal cord. Fluid within ventricles and central canal is called cerebrospinal fluid (CSF).

The Divisions of Brain

There are three major regions in the brain of human and other vertebrates. These are forebrain, midbrain and hindbrain. Important parts of each of these regions are described below:


Forebrain is the largest area of brain. It is most highly developed in humans. Following are the important
parts of this region.

  1. Thalamus lies just below cerebrum. It serves as a relay centre between various parts of brain and spinal cord. It also receives and modifies sensory impulses (except from nose) before they travel to cerebrum. Thalamus is also involved in pain perception and consciousness (sleep and awakening).
  2. Hypothalamus lies above midbrain and just below thalamus. In humans, it is roughly the size of an almond. One of the most important functions of hypothalamus is to link nervous system and endocrine system. It controls the secretions of pituitary gland. It also controls feelings such as rage, pain, pleasure and sorrow.
  3. Cerebrum is the largest part of forebrain. It controls skeletal muscles, thinking, intelligence and emotions. It is divided into two cerebral hemispheres. The anterior parts of cerebral hemispheres are called olfactory bulbs which receive impulses from olfactory nerves and create the sensation of smell. The upper layer of cerebral hemispheres i.e. cerebral cortex consists of grey matter. The grey matter of nervous system consists of cell bodies and non-myelinated axons. Beneath this layer is present the white matter. The white matter of nervous system consists of myelinated axons. Cerebral cortex has a large surface area and is folded in order to fit in skull. It is divided into four lobes.

Midbrain lies between hindbrain and forebrain and connects the two. It receives sensory information and sends it to the appropriate part of forebrain. Midbrain also controls some auditory reflexes and posture.


Hindbrain consists of three major parts.

  1. Medulla oblongata lies on the top of spinal cord. It controls breathing, heart rate and blood pressure. It also controls many reflexes such as vomiting, coughing, sneezing etc. Information that passes between spinal cord and the rest of brain pass through medulla.
  2. Cerebellum is behind medulla. It coordinates muscle movements.
  3. Pons is present on top of medulla. It assists medulla in controlling breathing. It also serves as a connection between cerebellum and spinal cord.
B- Spinal Cord:

The spinal cord is in fact a tubular bundle of nerves. It starts from brain stem and extends to lower back. Like brain, spinal cord is also covered by meninges. The vertebral column surrounds and protects spinal cord.

The outer region of spinal cord is made of white matter (containing myelinated axons). The central
region is butterfly shaped that surrounds the central canal. It is made of grey matter (containing neuron cell bodies).

31 pairs of spinal nerves arise along spinal cord. These are “mixed” nerves because each contains axons of both sensory and motor neurons.

At the point where a spinal nerve arises from spinal cord, there are two roots of spinal nerve.
Both roots unite and form one mixed spinal nerve.

  • The dorsal root contains sensory axons and a ganglion where cell bodies are located.
  •  The ventral root contains axons of motor neurons.

Spinal cord performs two main functions:

  1.  It serves as a link between body parts and brain. Spinal cord transmits nerve impulses from body parts to brain and from brain to body parts.
  2. Spinal cord also acts as a coordinator, responsible for some simple reflexes

Previous Lectures:

Gaseous Exchange



Homeostasis may be defined as the maintenance of the internal conditions of body at equilibrium, despite changes in the external environment. For example, the core temperature of human body remains at about 37°C despite fluctuations in the surrounding air temperature. Similarly, the blood glucose level remains about 1g per litre despite eating a meal rich in carbohydrates. Body cells need the internal environment in which conditions do not change much. Stable internal conditions are important for the efficient functioning of enzymes. The following are some process of homeostasis. Osmoregulation: It is maintenance of the amounts of water and salts in body fluids (i.e. blood and tissue fluids). We know that the relative amounts of water and salts in body fluids and inside cells control by the processes of diffusion and osmosis, which are essential for the functioning of cells
(Recall “the concept of tonicity” from Grade IX Biology). Thermoregulation: The maintenance of internal body temperature is called thermoregulation. The enzymes of body work best at particular temperatures (optimum temperature). Any change in body temperature may affect the functioning of enzymes. Excretion is also a process of homeostasis. In this process, the metabolic wastes are eliminated from body to maintain the internal conditions at equilibrium.

Metabolic waste means any material that is produced during body metabolism and that may harm the body

Homeostasis In Plants:

Plants respond to environmental changes and keep their internal conditions constant i.e. homeostasis. They apply different mechanisms for the homeostasis of water and other chemicals (oxygen, carbon dioxide, nitrogenous materials etc)

Removal of Extra Carbon dioxide and Oxygen:

In daytime, the carbon dioxide produced during cellular respiration is utilized in photosynthesis and hence it is not a waste product. At night, it is surplus because there is no utilization of carbon dioxide. It is removed from the tissue cells by diffusion. In leaves and young stems, carbon dioxide escapes out through stomata. In young roots, carbon dioxide diffuses through the general root surface, especially through root hairs. Oxygen is produced in mesophyll cells only during daytime, as a by-product of photosynthesis. After its utilization in cellular respiration, the leaf cells remove the extra amount of oxygen through stomata.

Removal of Extra Water:

We know that plants obtain water from soil and it is also produced in the body during cellular
respiration. Plants store large amount of water in their cells for turgidity. Extra water is removed from plant body by transpiration. At night, transpiration usually does not occur because most plants have their stomata closed. If there is a high water content in soil, water enters the roots and is accumulated in xylem vessels. Some plants such as grasses force this water through special pores, present at leaf tips or edges, and form drops. The appearance of drops of water on the tips or edges of leaves is called guttation.

Removal of Other Metabolic Wastes:

Plants deposit many metabolic wastes in their bodies as harmless insoluble materials. For example, calcium oxalate is deposited in the form of crystals in the leaves and stems of many plants e.g. in tomato

The removal of excretory products is a secondary function of leaf fall. If the leaves are not shed, the calcium oxalate just remains as harmless crystals in the leaves

In trees which shed their leaves yearly, the excretory products are removed from body during leaf fall. Other waste materials that are removed by some plants are resins (by coniferous trees), gums (by keekar), latex (by rubber plant) and mucilage (by carnivorous plants and ladyfinger) etc.

Osmotic Adjustments in Plants:

On the basis of the available amount of water and salts, plants are divided into three groups.


Are the plants which live completely or partially submerged in freshwater. Such plants do not face the problem of water shortage. They have developed mechanisms for the removal of extra water from their cells. Hydrophytes have broad leaves with a large number of stomata on their upper surfaces. This characteristic helps them to remove the extra amount of water. The most common example of such plants is water lily.


Live in dry environments. They possess thick, waxy cuticle over their epidermis to reduce water loss from internal tissues. They have less number of stomata to reduce the rate of transpiration. Such plants have deep roots to absorb maximum water from soil. Some xerophytes have special parenchyma cells in stems or roots in which they store large quantities of water. This makes their stems or roots wet and juicy, called succulent organs. Cacti (Singular
Cactus) are the common examples of such plants.


Live in sea waters and are adapted to salty environments. Salts enter in the bodies of such plants due to their higher concentration in sea water. On the other hand, water tends to move out of their cells into the hypertonic sea water. When salts enter into cells, plants carry out active transport to move and hold large amount of salts in vacuoles. Salts are not allowed to move out through the semi- permeable membranes of vacuoles. So the sap of vacuoles remains even more hypertonic than sea water. In this way, water does not move out of cells. Many sea grasses are included in this group of plants.

Osmosis is the movement of water from hypotonic solutions (less solute concentration) to hypertonic solutions (higher solute concentration), through semipermeable membrane.

Homeostasis In Humans:

Like other complex animals, humans have highly developed systems for homeostasis. The following are the main organs which work for homeostasis:

  • Lungs remove excess carbon dioxide and keep it in balance.
  •  Skin performs role in the maintenance of body temperature and also removes excess water and salts.
  •  The kidney filters excess water, salts, urea, uric acid etc. from the blood and forms urine.


We know that our skin consists of two layers. Epidermis is the outer protective layer without blood vessels while dermis is the inner layer containing blood vessels, sensory nerve endings, sweat and oil glands, hairs and fat cells. Skin performs important role in the regulation of body temperature. The thin layer of fat cells in the dermis insulates the body. Contraction of small muscles attached to hairs forms ‘Goosebumps’. It creates an insulating blanket of warm air.

Similarly, skin helps in providing cooling effect when sweat is produced by sweat glands and excess body heat escapes through evaporation. Metabolic wastes such as excess water, salts, urea and uric acid are also removed in sweat.


In the previous chapter we have learned how lungs maintain the concentration of carbon dioxide
in the blood. Our cells produce carbon dioxide when they perform cellular respiration. From cells,
carbon dioxide diffuses into tissue fluid and from there into blood. Blood carries carbon dioxide to
lungs from where it is removed in air.

The Urinary System Of Humans:

The excretory system of humans is also called the urinary system. It is formed of one pair of kidneys, a pair of ureters, a urinary bladder and a urethra. Kidneys filter blood to produce urine and the ureters carry urine from kidneys to urinary bladder. The bladder temporarily stores urine until it is released from body. Urethra is the tube that carries urine from urinary bladder to the outside of body.

Structure of Kidney:

Kidneys are dark-red, bean shaped organs. Each kidney is 10 cm long, 5 cm wide and 4 cm thick and weighs about 120 grams. They are placed against the back wall of abdominal cavity just below diaphragm, one on either side of vertebral column. They are protected by the last 2 ribs. The left kidney is a little higher than the right. The concave side of kidney faces vertebral column. There is a depression, called hilus, near the centre of the concave area of kidney. This is the area of kidney through which ureter leaves kidney and other structures including blood vessels, lymphatic vessels and nerves enter and leave kidney.

The longitudinal section of the kidney shows two regions. Renal cortex is the outer part of kidney and it is dark red in color. Renal medulla is the inner part of kidney and is pale red in color. Renal medulla consists of several cone shaped areas called renal pyramids. Renal pyramids project into a funnel-shaped cavity called renal pelvis, which is the base of ureter.

The functional unit of the kidneys is called nephron. There are over one million nephrons in each kidney. There are two parts of a nephron i.e. renal corpuscle and renal tubule . The renal


corpuscle is not tubular and has two parts i.e. glomerulus and Bowman’s capsule. Glomerulus is a network of capillaries while Bowman’s capsule is a cup-shaped structure that encloses glomerulus. The renal tubule is the part of nephron which starts after Bowman’s capsule. Its first portion is called the proximal convoluted tubule. Next portion is U-shaped and is called the Loop of Henle. The last portion of renal tubule is the distal convoluted tubule. The distal convoluted tubules of many nephrons open in a single collecting ducts. Many collecting ducts join together to form several hundred papillary ducts which drain into renal pelvis.

Functioning of Kidney:

The main function of kidney is urine formation, which takes place in three steps . The first
step is pressure filtration. When blood enters the kidney via the renal artery, it goes to many arterioles, and then to the glomerulus. The pressure of blood is very high and so most of the water, salts, glucose and urea of blood is forced out of glomerular capillaries. This material passes into the Bowman’s capsule and is now called glomerular filtrate.

The second step is the selective re-absorption. In this step about 99% of the glomerular filtrate is reabsorbed into the blood capillaries surrounding renal tubule. It occurs through osmosis, diffusion and active transport. Some water and most of the glucose is reabsorbed from the proximal convoluted tubule. Here, salts are reabsorbed by active transport and then water follows by osmosis. The descending limb of loop of Henle allows the reabsorption of water while the ascending limb of Loop of Henle allows the reabsorption of salts. The distal convoluted tubule again allows the reabsorption of water into the blood. The third step is the tubular secretion. Different ions, creatinine, urea etc. are secreted from blood into the filtrate in renal tubule. This is done to maintain blood at a normal pH (7.35 to 7.45).

After the above mentioned steps, the filtrate present in renal tubules is known as urine. It moves into collecting ducts and then into pelvis.

Osmoregulatory Function of Kidney:

Osmoregulation is defined as the regulation of the concentration of water and salts in blood and other body fluids. Kidneys play important role in osmoregulation by regulating the water contents of blood. It is an important process as excessive loss of water concentrates the body fluids whereas excess intake of water dilutes them.

When there is excess water in body fluids, kidneys form dilute (hypotonic) urine. For this purpose, kidneys filter more water from glomerular capillaries into Bowman’s capsule. Similarly less water is reabsorbed and abundant dilute urine is produced. It brings down the volume of body fluids to normal. When there is shortage of water in body fluids, kidneys filter less water from glomerular capillaries and the rate of reabsorption of water is increased. Less filtration and more reabsorption produce small amount of concentrated (hypertonic) urine. It increases the volume of body fluids to normal. This whole process is under hormonal control.

Disorders Of Kidney:

There are many different kidney disorders.

Kidney (Renal) failure:

Kidney failure means a complete or partial failure of kidneys to function. Diabetes mellitus and hypertension are the leading causes of kidney failure. In certain cases, sudden interruption in the blood supply to kidney and drug overdoses may also result in kidney failure. The main symptom of kidney failure is the high level of urea and other wastes in blood, which can result in vomiting, nausea, weight loss, frequent urination and blood in urine. Excess fluids in body may also cause swelling of legs, feet face and shortness of breath. The kidney failure is treated with dialysis and kidney transplant.

1 Dialysis:

Dialysis means the cleaning of blood by artificial ways. There are two methods of dialysis.

 A. Peritoneal Dialysis:

In this type of dialysis, the dialysis fluid is pumped for a time into the peritoneal cavity which is the space around gut . This cavity is lined by peritoneum. Peritoneum contains blood vessels. When we place dialysis fluid in peritoneal cavity, waste materials from peritoneal blood vessels diffuse into the dialysis fluid, which is then drained out. This type of dialysis can be performed at home, but must be done every day.

B. Haemodialysis:

In haemodialysis, patient’s blood is pumped through an apparatus called dialyzer. The dialyzer contains long tubes, the walls of which act as semi-permeable membranes (Fig. 11.12). Blood flows through the tubes while the dialysis fluid flows around the tubes. Extra water and wastes move from blood into the dialysis fluid. The cleansed blood is then returned back to body. The haemodialysis treatments are typically given in dialysis centres.

2. Kidney Transplant:

We know that dialysis needs to be repeated after every few days and is unpleasant for patients and
attendants. Another treatment for the end-stage kidney failure is kidney transplantation. It is the replacement of patient’s damaged kidney with a donor healthy kidney. Kidney may be donated by a deceased-donor or living-donor. The donor may or may not be a relative of the patient. Before transplant, the tissue proteins of donor and patient are matched. The donor’s kidney is transplanted in patient’s body and is connected to the patient’s blood and urinary system. The average lifetime for a donated kidney is ten to fifteen years. When a transplant fails, the patient may be given a second kidney transplant. In this situation, the patient is treated through dialysis for some intermediary time. Problems after a transplant may include transplant rejection, infections, imbalances in body salts which can lead to bone problems and ulcers.

Previous Lectures:

Gaseous Exchange



Gaseous Exchange

In Grade IX, we have studied how cells generate ATPs from food. Cellular respiration is the process in which the C-H bonds in food are broken by oxidation reduction reactions and the energy is transformed into ATP. In aerobic respiration, oxygen is used and there is complete oxidation of the food material. Carbon dioxide and water are also produced in this process. Organisms get the oxygen, needed for cellular respiration, from their environment and provide it to their cells. The carbon dioxide produced during cellular respiration is taken out of the cells and ultimately from the body. Taking in oxygen and giving out of carbon dioxide is termed as gaseous exchange.
The term breathing is used for the process through which animals take air in their bodies to get oxygen from it and then give out the air for getting rid of carbon dioxide. Thus breathing and respiration are not synonymous. Respiration involves the mechanical and the bio-chemical processes whereas breathing is only the mechanical or physical process of exchange of gases.
In this chapter we will go through the mechanisms of gaseous exchange in plants and
in humans.

Gaseous Exchange In Plants:

Plants have no organs or systems for the exchange of gases with the environment. Every cell of the plant body exchanges gases with the environment by its own. The leaves and young stems have stomata in their epidermis. The gaseous exchange occurs through these stomata. The inner cells of leaves (mesophyll) and stems also
have air spaces among them, which help in the exchange of gases.

Leaf cells face two situations. During the daytime when the mesophyll cells of leaves are carrying out photosynthesis and respiration side by side, the oxygen produced in photosynthesis is utilized in cellular respiration. Similarly the carbon dioxide produced during cellular respiration is utilized in photosynthesis. However, during night when there is no photosynthesis occurring, the leaf cells get oxygen from the environment and release carbon dioxide through stomata.

In woody stems and mature roots, the entire surface is covered by bark which is impervious to gases or water. However, there are certain pores in the layer of bark. These are called the lenticels. The lenticels allow air to pass through them. Gases diffuse in and out of the general surface of the young roots. The gases are found in the soil surrounding the roots. The aquatic plants get the oxygen dissolved in water and release carbon dioxide in the

Gaseous Exchange In Humans:

In humans and other higher animals the exchange of gases is carried out by the respiratory system. We can divide the respiratory system in two parts i.e. the air passageway and the lungs.

  • The Air Passageway:

The air passageway consists of the parts through which the outside air comes in the lungs and after the exchange of gases it goes out. This passage of air consists of the following parts. The nose encloses the nasal cavity. It opens to the outside through the openings called the nostrils. The nasal cavity is divided into two portions by a wall. Each portion is lined by fine hairs and mucous which filter the dust particles from the air. The mucous also moistens and warms the incoming air and keeps its temperature nearly equal to that of the body.
On entering the chest cavity, the trachea divides into two smaller tubes called bronchi (Singular: bronchus). The bronchi also have cartilaginous plates in their walls. Each bronchus enters into the lung of its side and then divides into smaller branches. The bronchi continue dividing in the lungs until they make several fine tubes called bronchi-oles. The bronchi-oles progressively lose the cartilages as they become narrower. The bronchi-oles end as fine tubules called the alveolar ducts. Each alveolar duct opens into a cluster of pouches called alveoli. The alveoli form the respiratory surface in human body. Each alveolus is a sac-like structure lined by a single layer of epithelial cells. It is bound on the outside by a network of capillaries. The pulmonary artery from the heart containing deoxygenated blood enters the lungs and branches into arterioles and then into capillaries which surround the alveoli. These then join together to form the venules which form pulmonary vein. The pulmonary vein carries the oxygenated blood back to the heart.

The vibrations in vocal cords and the movements of lips, cheeks, tongue and jaws produce
specific sounds which result in speech. Speech is an ability that only humans are gifted with and
this is one of the characteristics which has put human beings superior to all.

  • The Lungs:

All the alveoli on one side constitute a lung. There is a pair of lungs in the thoracic cavity. The chest wall is made up of 12 pairs of ribs and the rib muscles called intercoastal muscles. A thick muscular structure, called diaphragm, is present below the lungs.

The left lung is slightly smaller and has two lobes and the right lung is bigger with three lobes. They are spongy and elastic organs. The lungs also have blood vessels that are the branches of the pulmonary arteries and veins. Each lung is enclosed by two membranes called the outer pleural membrane and the inner pleural membrane. The membranes enclose a fluid which provides lubrication for the free expanding and contracting of the lungs.

Photo by Robina Weermeijer on Unsplash

  • The Mechanism of Breathing:

The physical movements associated with the gaseous exchange are called breathing. There are two phases of breathing i.e. inhalation and exhalation.


Photo by Elijah Hiett on Unsplash

1. Inspiration or Inhalation:

During inspiration, the rib muscles contract and ribs are raised. At the same time the dome-shaped diaphragm contracts and is lowered. These movements increase the area of the thoracic cavity, which reduces the pressure on lungs. As a result, the lungs expand and the air pressure within them also decreases. The air from outside rushes
into the lungs to equalize the pressure on both sides.

The breathing movements are involuntary to a large extent. However, we can control the
rate of breathing but not for a long time.

2. Expiration or Exhalation:

After the gaseous exchange in the lungs, the impure air is expelled out in exhalation. The rib muscles relax bringing the ribs back to the original position. The diaphragm muscles also relax and it gets its raised dome shape. This reduces the space in the chest cavity and increases the pressure on lungs. The lungs contract and the air is expelled out of them. Humans breathe 16 -20 times per minute in normal circumstances i.e. at rest. The rate of breathing is controlled by the respiratory centre in the brain. The respiratory centre is sensitive to the concentration of carbon dioxide in the blood. When we do exercise or some hard job our muscle cells carry out cellular respiration at a greater rate. It results in the production of more carbon dioxide which is released in the blood. This greater than normal concentration of carbon dioxide stimulates the respiratory centre of brain. The respiratory centre sends messages to the rib muscles and diaphragm to increase the rate of breathing so that the excess carbon dioxide present in blood can be removed out of body. During exercise or other hard physical works the breathing rate may increase up to 30-40 times per minute.

Comparison between the inspired and expired air

Feature Inspired Air Expired Air
Amount of oxygen 21% 16%
Amount of carbon dioxide 0.04% 4%
Amount of nitrogen 79% 79%
Amount of water vapors Variable Saturated
Amount of dust particles Variable Almost None
Temperature Variable Almost equal to body temperature

Respiratory Disorders:

There are a number of respiratory disorders which affect people. The percentage of such disorders is particularly high in Pakistan. It is due to the more concentration of air pollutants not only in the urban but also in the rural atmosphere. Some of the important respiratory disorders are described next.

1. Bronchitis:

Bronchitis is the inflammation of the bronchi or bronchioles. It results in excessive secretions of mucus into the tubes, leading to the swelling of tubular walls and narrowing of tubes . It is caused by viruses, bacteria or exposure to chemical irritants (e.g. tobacco smoke).

There are two major types of bronchitis i.e. acute and chronic. The acute bronchitis usually lasts about two weeks and patients recover with no permanent damage to the bronchi or bronchioles. In chronic bronchitis, the bronchi develop chronic inflammation. It usually lasts for three months to two years.


Symptoms of bronchitis include a cough, mild wheezing, fever, chills and shortness of breath (especially when doing hard job).

2. Emphysema:

Emphysema is the destruction of the walls of the alveoli. It results in larger sacs but with less surface area for gaseous exchange . As lung tissue breaks down, the lungs do not come back to their original shape after exhalation. So air cannot be pushed out and is trapped in the lungs.

The majority of people diagnosed with chronic bronchitis are 45 years of age or older.

The symptoms of emphysema include shortness of breadth, fatigue, recurrent respiratory infections and weight loss. By the time the symptoms of emphysema appear, the patient has usually lost 50% to 70% of his / her lung tissue. The level of oxygen in blood may get so low that it causes serious complications.

3. Pneumonia

Pneumonia is an infection of lungs. If this infection affects both lungs then, it is called double pneumonia. The most common cause of pneumonia is a bacterium, Streptococcus pneumoniae.

Some viral (influenza virus) and fungal infections may also lead to pneumonia. When the causative organisms enter the alveoli, they settle there and grow in number. They break the lung tissues and the area becomes filled with fluid and pus.


The symptoms of pneumonia include a cold that is followed by a high fever, shivering, and a cough with sputum production. Patient may become short of breath. The patient’s skin colour may change and become dusky or purplish. It is due to poor oxygenation of blood. Vaccines are available to prevent pneumonia caused by S. pneumoniae. Antibiotics are used in the treatment of this type of pneumonia.

Prior to the discovery of antibiotics, one-third of pneumonia patients died from the infection

4. Asthma

Asthma is a form of allergy, in which there is inflammation of the bronchi, more mucous production and narrowing of the airways. In asthma patients, the bronchi and bronchioles become sensitive to different allergens (allergy causing factors) e.g. dust, smoke, perfumes, pollens etc. When exposed to any of such allergens, the sensitive airways
show immediate and excessive response of constriction. In this condition, the patient feels difficulty in breathing.


The symptoms of asthma vary from person to person. The major symptoms include shortness of breath (especially with exertion or at night), wheezing (whistling sound when breathing out), cough and chest tightness. The chemicals with ability to dilate the bronchi and bronchioles are used in the treatment of asthma. Such medicine is given in the form of inhalers.

5. Lung Cancer:

Lung cancer is a disease of uncontrolled cell divisions in the tissues of the lung. The cells continue to divide without any control and form tumors. The cellular growth may also invade adjacent tissues beyond the lungs. The most common symptoms are shortness of breath, coughing (including coughing up blood) and weight loss.

Lung cancer is the most common cause of cancer-related deaths and is responsible for more than 1.3 million deaths worldwide annually

The main causes of any cancer include carcinogens (such as those in cigarette smoke), ionizing radiation and viral infection. Smoking is the main cause of lung cancer. This risk of lung cancer is significantly lower in non smokers. Cigarette smoke contains over 50 known carcinogens. Passive smoking (the inhalation of smoke from another’s smoking) is also a cause of lung cancer. The smoke from the burning end of a cigarette is more dangerous than the smoke from the filter end.

Eliminating tobacco smoking is a primary goal in the prevention of lung cancer. The World Health Organization has called for governments to stop tobacco advertising to prevent young people from taking up smoking.

Bad Effects of Smoking:

Smoking is harmful due to the chemicals in cigarettes and smoke. Tobacco smoke contains over 4,000 different chemicals, out of which at least 50 are carcinogens and many are poisonous. Many people think that lung cancer is the only smoking-related disease and it is the number one cause of death among smokers. But it is not right. Cigarette smoke affects the body from head to toe. Smokers have a much higher risk of developing a number of life threatening diseases.

If a person stops smoking, the chance to develop cancer decreases as damage to the lungs is repaired and contaminant particles are gradually removed.
Nicotine is a powerful poison and was widely used as an insecticide in the past. When inhaled through tobacco smoking, it reaches our circulatory system and not only hardens the walls of the arteries but also damages the brain tissues.
According to the WHO, the rates of smoking have declined in the developed world. In the developing world, however, it is rising by 3.4% per year as of 2002

Smoking may also lead to the cancers in kidneys, oral cavity, larynx, breast, bladder and pancreas etc. Many chemicals in tobacco smoke damage the air passageway, which leads to emphysema and other respiratory disorders.

The World No Tobacco Day is celebrated on the 31st of May every year

Smoking also has effects on the circulatory system. The carbon monoxide present in tobacco smoke lessens the oxygen-carrying capacity of haemoglobin. Many other chemicals in smoke increase the production of blood platelets. When platelets are more than the normal numbers, they make the blood viscous and it can lead to arteriosclerosis. Smokers are at greater risk of developing infections, particularly in the lungs. For example, smoking increases the risk of tuberculosis by two to four times, and of pneumonia by four times. Smoking is also responsible for weakening and staining the teeth. Tooth loss is 2 to 3 times higher in smokers than in non-smokers.

Non-smokers who are exposed to second-hand smoke (passive smoke) at home or work increase their heart disease risk by 25-30% and their lung cancer risk by 20-30%


Canon EOS 1300d Basic Information

 Canon 1300d

(picture credits Christainu)


EOS 1300d is the is made by Canon. Canon is well known brand in this  world in its DSLR cameras.


Mostly a lens 18-55 is provided with the body of Canon 1300d. But you can buy your own to make it more professional.

Built In Flash

We know that photography in different situations needs a flash, such as low light character photography where you need a flash to lighten up the face of your character. So this camera has a built in flash for its low light photography. Yes it not good for video making but it is necessary for photography.


As we are well aware that most camera do not have any internal memory. Same is with this 1300d. This supports SD memory card. There are different size of SD Cards are available in market. I mostly use 32 GB SD cards.

Battery Life

Yeah we can not confirm the exact battery life of these DSLRs, these are vary with the usage of the camera and battery. I recommend you to buy extra batteries if you are going to buy a DSLR camera.


Many cameras do not support Wifi connection, but 1300d comes with wifi support. Means you can connect wifi with it for different purposes. I mainly  use wifi connection to store my images in cell phone.

Maximum ISO

This  camera is good in low light shooting of film and photos, because it has a maximum ISO of 6400, which is really a good ISO.

Video Quality

This camera does not record 4k video, but its quality is really good. You can record high quality HD Video in it.


I am not aware of pixels in these cameras but what we know if pixels increases then the quality of video will increase. 1300d has a 18 pixel camera.

Video Resolution

The video resolution of Canon 1300d is not so high, but it is good. This camera record video in HD 720 resolution which is not too bad.

So these are basic information related to the 1300d. But it does not support external mic. If you are a filmmaker, consider to buy a camera with external mic support. It is good for photographers.

3 Gadgets For Fresh Filmmakers

Film making is the art of visual storytelling , you are showing the story rather then writing or telling the story by moving pictures. Elements for filmmaking include, a story, actors, scripts and things which are used in your film (Shortly Describing). For new filmmakers it is difficult to choose the things which fit on their budget, but remember without gadgets you can not start your filmmaking at least you will need a camera for making a film.

There are 10 gadgets for filmmakers to start, are written below.

فلم بنانا ایک آرٹ ہے جس میں ویژول طریقے سے کہانی بتائی جاتی ہے،اس میں آپ کہانی کو بتانے یا لکھنے کے بجائے فوٹو کی صورت میں بتا رہے ہوتے ہیں۔ فلم بنانے کے لئے چند چیزوں کی ضرورت ہوتی ہے جیسے کہ کہانی، اداکار، اسکرپٹ اور وہ چیزیں جو فلم میں استعمال ہوں(مختصراَبتا رہا ہوں)۔ نئے فلم میکرز کے لئے چیزیں لینا بہت مشکل ہے خاص کر ان کے بجٹ کے مطابق، لیکن یاد رکھیں کہ آپ تب تک فلم نہیں بنا سکتے جب تک کم از کم آپ کے پاس ایک کیمرہ نہ ہو۔

نئے فلم میکرز کے لئے دس چیزیں مندرجہ زیل ہیں۔

1. Camera

Camera is the most important thing in filmmaking, just like you can not play cricket without bat, you can not make a film without a camera. There are many camera companies such as Canon, Panasonic, Nikon and list goes further, but you have to choose wisely. As i  said there are many camera companies, so prices are difference by their work. If you are new in filmmaking you must use a lower rate camera. There are Good cameras in Canon. Such as Canon 1300D or many others, and prices are 30000 to above.

فلم میکینگ میں کیمرہ بہت اہمیت رکھتا ہے۔ جس طرح آپ بنا بلے کے کرکٹ نہیں کھیل سکتے اسی طرح بنا کیمرے کے فلم نہیں بنا سکتے۔کیمروں کے بہت سے کمپنی ہیں،جیسے کینن،پیناسونک ،نکون اور یہ لسٹ آگے چلتا جاتا ہے،لیکن آپ کو کیمرہ عقلمندی سے لینا پڑیگا۔ کینن میں بہت اچھے کیمرے ملتے ہیں جیسا کہ کینن  1300اور بھی بہت سے ہیں، اور جن کی قیمت30000 سے اوپر ہے۔

But i  will  advice you if you are new and buying a professional camera so don’t waste your money with cameras which does not support external mic. Remember an important thing in filmmaking is your sound quality, so i suggest you to buy Canon 600d which is cheapest in price compared to other professional cameras and supports external mic. Its price is nearly Rs. 40000. Don’t waste your money on wrong things. But if you are a photographer and starting your journey you can buy a camera without external support of mic.

لیکن میرا آپ کو یہی مشورہ ہے، اگر آپ نئے ہیں اور ایک پروفیشنل کیمرہ خریدنا چاہتے ہیں تو اپنا پیسا اس کیمرے پر ہر گز ضائع نہ کریں جس میں مائک نہیں لگتا۔ یاد رکھئے گا فلم بنانے میں آواز ایک بہت اہم چیز ہے، تو اس لئے میں کیتا ہوں اگر آپ کیمرہ لیتے ہیں تو کینن کی 600د لیں۔ جو قیمت کےلحاظ سے بھی باقی پروفیشنل کیمروں سے سستا ہے اور مائک بھی جس پر لگتا ہے۔اس کے قیمت 40000 کے قریب ہے۔لیکن اگر آپ فوٹوگرافر ہیں اور اپنے سفر کی شروعات کر رہے ہیں تو پھر کوئی بھی کیمرہ چل سکتا ہے۔

2۔ Tripod/Monopod

Tripod or monopod is used in filmmaking, remember filmmaking is not equal to other videography such as making a video of a news anchor. It is quite different then these types of video. In filmmaking your camera must move with the scene quality. It must not be still on a single place other wise your scene will be boring, but you can not shake camera here and there because shaking of camera put a negative effect on the quality of film. So there are two things for making a film in a better way, one is to use a Tripod, other is to use a monopod.

ٹرائی پوڈ یا مونوپوڈ کا استعمال فلم میکینگ میں ہوتا ہے، یاد رکھئےگا فلم بنانا باقی کے ویڈیو بنانے سے مختلف ہے جیسا کہ کسی اینکر کا ویڈیو بنانا۔ یہ یس طرح کے ویڈیو بنانے سے بہت مختلف ہے۔ فلم میکنگ میں آپ کا کیمرہ سین کے مطابق حرکت کرنی چاہئے۔ اسے ایک ہی جگہ نہیں ہونا چاہئے ورنہ آپ کا سین بہت ہی بورنگ ہوگا،لیکن آپ کیمرے کو ہہاں وہاں فضول میں حرکت بھی نہیں دے سکتے ورنہ دیکھنے والوں پر منفی اثرات مرتب ہونگے۔ تو دو چیزیں ہیں جن کا آپ اچھے سے استعمال کر سکتے ۔ہیں فلم میکنگ میں، ایک مونوفواڈ ہے اور ایک ہے ٹرائی فوڈ

A tripod has three legs and same a monopod has a single leg. I recommend you to buy a monopod stand. Monopod can work better than a tripod in filmmaking, as i said your camera must not be in a single place, so with monopod you can move camera with your scene quality and it does not shake like it shakes in your hands. And what i know a monopod is cheaper than a professional tripod.

ٹرائی فوڈ کے تین پاؤں ہوتے ہیں جبکہ مونوفوڈ کا ایک ہوتا ہے۔ میں آپ کو مونوفوڈ لینے کا کہونگا ۔ مونوفوڈ فلم بنانے میں بہتر کام کر سکتا ہے جیسا کہ میں نے کہا آپ کا کیمرہ اسٹل نہیں ہونا چائیے، تو مونوفوڈ کے ساتھ آپ کیمرے کو بہترین طریقے سے حرکت دے سکتے ہیں اور یہ اس طرح ہلےگا بھی نہیں جس طرح ہاتھ میں ہلتا ہے۔ اور جہاں تک مجھے پتا ہے مونوفوڈ ٹرائی فوڈ سے سستا بھی ہے۔

3. Mic

Here is a question raise that why am i asking you to buy a mic? does these DSLR camera do not record voice? answer is they record your voice, but remember the above paragraph where i have cleared that voice is an important thing in your film. If there are dialogues in your film, you must use a mic. Other wise you do not  use a mic in my films than it sucks when you listen air more then the dialogues of an actor.

یہاں ایک سوال اٹھتا ہے کہ میں مائک لینے کا کیوں کہ رہا ہوں؟ کیا یہ ڈی ایس ایل آر کیمرہ آواز ریکارڈ نہیں کرتے؟جواب یہ ہے کہ آواز ریکارڈ کرتے ہیں، لیکن اوپر کا پیراگراف یاد کریں جہاں میں نے یہ کہا کہ فلم بنانے میں آواز ایک اہم چیز ہے۔اگر آپ کے فلم میں ڈائیالاگ ہیں،آپ کو ایک مائیک لینا چاہئے،اگر آپ مائیک کا استعمال نہیں کریں گے تو ایکٹر کے آوا ز کی جگہ ہوا کی آواز آئے گی۔

I recommend you to buy a ROD mic according to you budget. ROD is one of the best Mic companies. There are different mics and rates are different with there quality you can buy one. But remember it is must in filmmaking.

میں آپ سے یہی کہونگا کہ راڈ کا مائک اپنے حصیت کے حصاب سے لے لیں۔ راڈ مائک کے کمپنیوں میں سے بہترین کمپنی ہے۔راڈ کے مختلف مائک ہیں جن کی قیمت ان کے کام کے لحاظ سے مختلف ہے آپ کوئی ایک لے لیں۔ لیکن یاد رکھیں فلم بنانے میں یہ بہت ضروری ہے۔

What i think these are must have things in filmmaking, rather than these you should also have own made lighting kit if you do not afford to buy one. You can use own made dolleys as well and there are many things which you can buy or make for yourself. Remember filmmaking is a creativity, and you need to  be creative if you are going to make a film. Otherwise you may have high quality camera and lenses but if you are not creative , there is no value of your film.

If you have any suggestion and any tips in your mind, you can share yours in the comment section below.

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