Biology

Life Processes

Question:

(a) What criteria can be used to decide whether something is alive ?
(b) What is meant by life processes ? Name the basic life processes common to all living organisms which are essential for maintaining life.

Answer:

(a) The criteria to decide whether something is alive is the movement.
(b) The basic functions performed by living organisms to maintain their life on this earth are called life processes. The basic life processes common to all living organisms are ? Nutrition and Respiration; Transport and Excretion; Control and Coordination; Growth; Movement and Reproduction.

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Life Processes

Q 1.

(a) Name the pigment in leaves which absorbs sunlight energy.
(b) What is the colour of this pigment ?

Q 2.

What is the mode of nutrition in fungi?

Q 3.

What are enzymes? Name any one enzyme of our digestive system and write its function.

Q 4.

Name the green dot like structures in some cells observed by a student when a leaf peel was viewed under a microscope. What is this green colour due to?

Q 5.

What is the name of those cells in the leaf of a plant which control the opening and closing of stomata?

Q 6.

Name the enzyme present in human saliva. What type of food material is digested by this enzyme ?

Q 7.

Name the parts of the digestive system of a grasshopper.

Q 8.

What will happen if mucus is not secreted by the gastric glands?

Q 9.

Which part of the roots is involved in exchange of respiratory gases?

Q 10.

Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?

Q 11.

Name the green pigment present in the leaves of a plant.

Q 12.

Where is digested food absorbed into blood in human body ?

Q 13.

a) How do plants obtain food ?
(b) Why do plants need nitrogen ? How do plants obtain nitrogen ?

Q 14.

What are the functions of liver and pancreas in the human digestive system ?

Q 15.

Name one substance which is produced in anaerobic respiration by an organism but not in aerobic respiration.

Q 16.

Define nutrition? What are the different modes of nutrition?

Q 17.

Name the two stages in photosynthesis.

Q 18.

Define breathing.

Q 19.

Why is transpiration important for plants?

Q 20.

Explain the process of nutrition in Amoeba.

Q 21.

Draw a neat diagram of excretory system of human beings and label the following:
(i) Kidney
(ii) Ureter
(iii) Urinary Bladder
(iv) Urethra

Q 22.

A Give one reason why multicellular organisms require special organs for exchange of gases between their body and their environment. :

Q 23.

In addition to carbon dioxide and water, state two other conditions necessary for the process of photosynthesis to take place.

Q 24.

Why do we boil the leaf in alcohol when we are testing it for starch ?

Q 25.

What substances enter into the food vacuole in Amoeba to break down the food ?

Q 26.

What substance is mixed with food in the mouth during chewing by the teeth ?

Q 27.

What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?

Q 28.

Name the biological catalysts which bring about chemical digestion of food.

Q 29.

(a) What are heterotrophs ? Give one example of heterotrophs.
(b) What is the difference between autotrophic nutrition and heterotrophic nutrition ?

Q 30.

(a) Which part of the body secretes bile ? Where is bile stored ? What is the function of bile ?
(b) What is trypsin ? What is its function ?

Q 31.

Name the following :
(a) The process in plants which converts light energy into chemical energy.
(b) Organisms that cannot prepare their own food.
(c) Organisms that can prepare their own food.
(d) The cell organelle where photosynthesis occurs.
(e) The cells which surround a stomatal pore.
(f) An enzyme secreted by gastric glands in stomach which acts on proteins.

Q 32.

What are the different ways in which glucose is oxidised to provide energy in various organisms ? Give one example of each.

Q 33.

Explain why, when air is taken in and let out during breathing, the lungs always contain a residual volume of air.

Q 34.

Explain why, it is dangerous to inhale air containing carbon monoxide.

Q 35.

What would be the consequences of deficiency of haemoglobin in our bodies ?

Q 36.

Explain why, plants have low energy needs as compared to animals.

Q 37.

Explain how, it would benefit deep sea divers if humans also had gills.

Q 38.

How is respiration different from breathing?

Q 39.

In which kind of respiration is more energy released?

Q 40.

From where do the following take in oxygen?
(i) prawn (ii) rat.
Solution:

Q 41.

State the function of epiglottis.

Q 42.

What are the living organisms that cannot make their own food called?

Q 43.

What is compensation point?

Q 44.

How are fats digested in our bodies? Where does this process take place?

Q 45.

What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.

Q 46.

Describe double circulation in human beings. Why is it necessary?

Q 47.

What is the significance of emulsification of fats?

Q 48.

Why does absorption of digested food occur mainly in the small intestine?

Q 49.

Name the energy currency in the living organisms. When and where is it produced?

Q 50.

What are the functions of gastric glands present in the wall of the stomach?