Another characteristic of life is metabolism. All living organisms are made of chemicals. These chemicals, small and big, belonging to various classes, sizes, functions, etc., are constantly being made and changed into some other biomolecules. These conversions are chemical reactions or metabolic reactions. There are thousands of metabolic reactions occurring simultaneously Inside all living organisms, be they unicellular or multicellular. All plants, animals, fungi and microbes exhibit metabolism. The sum total of all the chemical reactions occurring in our body is metabolism. No non-living object exhibits metabolism. Metabolic reactions can be demonstrated outside the body in cell-free systems. An isolated metabolic reaction(s) outside the body of an organism, performed in a test tube is neither living nor non-living. Hence, while metabolism Is a defining feature of all living organisms without exception. Isolated metabolic reactions in vitro are not living things but surely living reactions. Hence, cellular organisation of the body is the defining feature of life forms.


The sum total of chemical reactions occurring in our body is called

(a) Metabolism

(b) Homeostasis

(c) Irritability

(d) Catabolism

(a)

 

What is wrong with respect to metabolism?

a. Chemical conversions or metabolic conversions are constantly going on

b. Metabolic reactions occur simultaneously

c. The sum total of all the chemical reaction occurring on the surface of our body is metabolism

d. No non-living objects exhibit metabolism

c

 

Isolated metabolic conversions in vitro are

a. Living things

b. Living reactions

c. Non- living conversions

d. Non-living things

b

 

What is wrong with respect to Living reactions?

a. Neither living nor non-living

b. Outside the body

c. Test tube reactions

d. Occurring in cells in the test tubes

d

 

 

 --------------- is the defining feature of living beings-------exception.

a. Metabolic reactions, with

b. Metabolism, without

c. Isolated metabolic reactions, without

d. Metabolism, with

b

 

According to all limitations, finally which is the defining feature of life forms?

a. Metabolism

b. Cellular organisation

c. Reproduction

d. Growth

b

 

Consider the following two statements:

I. Cellular organization of the body is the defining feature of life forms.

II. Metabolic reactions cannot be demonstrated outside the body in cell-free systems.

(a) Both I and II are true and II explains I

(b) Both I and II are true but II does not explain I

(c) I is true but II is false

(d) Both I and II are false

c

 



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