Biology

Life Processes

Question:

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

Answer:

There are two ways in which glucose is oxidized to provide energy in various organisms:
(i) Anaerobic respiration ? The respiration which takes place without oxygen is called anaerobic respiration.Example: Yeast and some bacteria break down glucose into ethanol and carbon dioxide.
(ii) Aerobic respiration ? The respiration which uses oxygen is called aerobic respiration.Example: Plants and animals break down glucose completely into carbon dioxide and water to release energy.

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

Q 26.

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

Q 27.

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

Q 28.

(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 29.

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 30.

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

Q 31.

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

Q 32.

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

Q 33.

In which kind of respiration is more energy released?

Q 34.

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

Q 35.

State the function of epiglottis.

Q 36.

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

Q 37.

What is compensation point?

Q 38.

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

Q 39.

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

Q 40.

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

Q 41.

What is the significance of emulsification of fats?

Q 42.

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

Q 43.

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

Q 44.

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

Q 45.

Mention the raw materials required for photosynthesis.

Q 46.

Write correct sequence of four steps of method for the preparation of temporary mount of a stained leaf peel.

Q 47.

(a) Draw a diagram of human respiratory system and label the following:
(i) part where air is filtered by fine hair and mucus
(ii) part which terminates in balloon – like structures
(iii) balloon – like structures where exchange of gases takes place. (iv) part which separates chest cavity from abdominal cavity.
(b) Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms?

Q 48.

What is saliva? State its role in the digestion of food.

Q 49.

(a) Draw a sectional view of the human heart and label on it – Aorta, Right ventricle and Pulmonary veins.
(b) State the functions of the following components of transport system:
(i) Blood (ii) Lymph

Q 50.

(a) Draw a diagram to show the nutrition in Amoeba and label the parts used for this purpose. Mention any other purpose served by this part other than nutrition.
(b) Name the glands associated with digestion of starch in human digestive tract and mention their role.
(c) How is required pH maintained in the stomach and small intestine?