Life Process -Chapter-6-Notes

What are life process?

All living organisms perform some basic functions or processes in order to remain alive. These processes are needed for the maintenance of their bodies and catching to their daily activities.

Some important life processes which are needed for living:

1. Nutrition

It is a process by which the organisms obtain and utilise the nutrients (food). These nutrients are the source of energy which come from outside the body of the individual organism.

2. Respiration 

It is a process that involves breakdown of nutrients through oxidation and release of energy for cellular needs. For this, many organisms take oxygen from outside the body.

3. Transport

In the case of single-celled organisms (e.g. amoeba), no specific organs for getting nutrients, oxygen, water or removal of wastes are needed because the entire body surface of such organisms remains in contact with the environment.

4. Excretion 

The biochemical reactions involved in assimilation of carbon dioxide, digestion of nutrients and oxidation of digested nutrients generate some by-products which are not only useless for the cells, but also cause toxic effect if not thrown out.

Differences between living and non-living things

Living thingsNon-living things
1. A living things has a self built organisation, consisting of several components, that exists beyond the level of individual.1. The organisation is imposed and limited.
2. Living things obtain simple molecules from outside and convert them into complex protoplasmic constituents2. Such activity is not seen. 
3. Living things perform growth, development and differentiation.3. No such activity occurs.
4. Living beings have property of self repair4. Non-living things have no such property. The repairs can only be done by outside agencies.
5. Living organisms have ability to sense the surroundings and protect themselves5. Protection of non-living things is imposed.
6. Living things have a definite life span.6. There is no definite life span.
7. Living beings reproduce and multiply. They produce offsprings and pass on genes to next generation.7.Multiplication is imposed.
8. Living organisms have ability to evolve in time.8. Non-living things do not have ability to evolve.

Modes of nutrients

Methods of obtaining food by the organisms in called modes of nutrition. Depending on the modes of obtaining nutrients, all the organisms can be classified in two major groups.

1. Autotrophic

2. Heterotrophic

Autotrophic mode of nutrition

Autotrophic nutrition is a kind of nutrition in which the organisms prepare (or synthesize) their own organic food utilising only the inorganic raw materials present in the surroundings.

Such organisms which can prepare their own organic food from inorganic raw materials and remain independent of external sources of organic carbon (compounds) for provision of their own organic constituents are called autotrophs.

Heterotrophic mode of nutrition

Heterotrophic nutrition is a kind of nutrition in which the organisms derive energy from the intake and digestion of the organic substances prepared by autotrophs and other organic sources.

Such organisms which depend on organic substances prepared by autotrophs and other organic sources are called heterotrophs.

Difference between autotrophs and heterotrophs

Autotrophs Heterotrophs
1. Autotrophs manufacture their own food from inorganic substances.1. Heterotrophs obtain their food from outside utilising organic substances.
2. These possess photosynthetic pigments for trapping light.2. These lack photosynthetic pigments for trapping light.
3. These convert light energy into chemical energy.3. These do not convert light energy into chemical energy.
4. Examples. All green plants, cyanobacteria.4. Examples. Animals, humans, parasites and fungi.

Types of heterotrophic nutrition

1. Saprophytic nutrition

Saprophytic nutrition refers to such kind of nutrition in which the organisms derive their nutrients from dead and decaying (rotten) organic matter (such as rotten leaves, rotten bread, dead animals, household wastes, non-living organic matter present in the soil, etc.)

2. Parasitic nutrition

Parasitic nutrition is a type of nutrition in which the organisms (or parasites) derive their nutrients or food from other living organisms.

Types of cellular respiration

Aerobic respiration:The oxidative breakdown of respiratory substrates with the help of atmospheric Ois known as aerobic respiration.

Glucose Pyruvic acid  CO+ H2O + Energy

Anaerobic respiration: Oxidation of respiratory substrates in absence of oxygen is termed as anaerobic respiration.

Glucose Pyruvic acid (in the absence ofO2)→C2H5OH + CO + Energy

Differences between Aerobic respiration and Anaerobic respiration

Aerobic RespirationAnaerobic Respiration
1. Aerobic respiration occurs in presence of Owhere Ois utilised.1. Anaerobic respiration occurs in absence of O2.  
2. Glucose is completely broken down to release the end products in the form of COand water.2. Glucose is completely oxidised to release the end products in the form of ethanol or lactic acid.
3. Energy release in larger amount.3. Energy is released in lesser amount.
4. It takes place in cytoplasm and mitochondria.4. It takes place in cytoplasm. The mitochondria are not involved. 

Difference between an artery and vein

1. It has thick, elastic, muscular wall.1. It has thin, non-elastic wall.
2. It has narrow lumen2. It has wide lumen
3. Flow of blood is fast and jerky3. Flow of blood is slow and smooth
4. It carries blood away from the heart to an organ.4. It carries blood from an organ towards heart.
5. It carries oxygenated blood (exception pulmonary artery).5. It carries deoxygenated blood (exception pulmonary vein). 

Double circulation

The blood circulation in human heart is double circulation. This means that the blood passes through the heart twice for each circuit of the body. One circulation involves the entry of blood from all body parts into the heart. This blood is deoxygenated which goes to lungs for oxygenation. The second circulation involves entry of oxygenated blood from lungs into the heart and then its distribution to all parts of the body. Double circulation is made possible because the human heart is divided into two halves. One half pump deoxygenated blood to the lungs and the other half pumps oxygenated blood to the rest of the body.

Renal failure and technology for survival

Kidneys are most vital organs for survival of the organisms. Through the kidneys remain active throughout the life, its efficiency gradually declines with normal ageing process. For example, its activity declines to about 50% by the age of 70 in human beings. The other causes of decline in the normal functioning of kidneys are diseases such as kidney infection, injury or restricted blood flow to kidneys. These abnormalities result in kidney damage and malfunctioning. A general term for decline in the performance of kidney due to a diseases is kidney failure. Though it is not common, it may result to death within a couple of weeks if not treated properly. Kidney failure is often due to build up of potassium ions which causes heart failure.

Q1. What is Double Circulation?

Q2. Types of Cellular respirations?

Q3. What is life Process?

7 thoughts on “Life Process -Chapter-6-Notes”

  1. 1. A circulatory system in which the blood travels twice through the heart in one complete cycle of the body is called double circulation .

  2. Homework

    Ans1.The blood is pass from the heart in our body parts and circulate our body is called double circulation.

    Ans2. Type of cellular respiration two type of cellular respiration.
    (1) Anaerobic respiration.
    (2) Aerobic respiration.

    Ans3.All living organisms some perform some basic activities in the order of alive. And we are doing some activities in our daily life is called life process.


Leave a Reply

%d bloggers like this: