Biology

Life Processes

Question:

Mention the major events during photosynthesis.

Answer:

The major events during photosynthesis are:
(i) Absorption of light energy by chlorophyll.
(ii) Conversion of light energy to chemical energy.
(iii) Splitting of H2O into H2,  O2  
(iv) Reduction of CO2to carbohydrates.

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Life Processes

Q 1.

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

Q 2.

State the three common features of all the respiratory organs like skin, gills and lungs.

Q 3.

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

Q 4.

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

Q 5.

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

Q 6.

What will happen if platelets were absent in the blood?

Q 7.

(a) Name the raw materials required for photosynthesis. How do plants obtain these raw materials ?
(b) What are the various conditions necessary for photosynthesis ?
(c) Name the various factors which affect the rate of photosynthesis in plants.

Q 8.

Name the final product/products obtained in the anaerobic respiration, if it takes place :
(a) in a plant (like yeast).
(b) in an animal tissue (like muscles).

Q 9.

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

Q 10.

How are the alveoli designed to maximise the exchange of gases?

Q 11.

What are the adaptations of leaf for photosynthesis?

Q 12.

State the role of the following in human digestive system :
(i) Digestive enzymes (ii) Hydrochloric acid (iii) Villi

Q 13.

(a) What is meant by breathing? What happens to the rate of breathing during vigorous exercise and why?
(b) Define translocation with respect to transport in plants. Why is it essential for plants? Where in plants are the following synthesised?
(i) Sugar (iii) Hormone

Q 14.

Name two inorganic substances which are used by autotrophs to make food.

Q 15.

What moves the food in the digestive organs ?

Q 16.

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

Q 17.

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

Q 18.

(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.

Q 19.

What is the other name of wind-pipe ?

Q 20.

Fill in the following blanks with suitable words :
(a) The organs of respiration in man are the…………..
(b) The actual exchange of gases takes place in the………… of the lungs.
(c) ………………in the lungs provide a very large surface area for gaseous exchange.
(d) Yeast undergoes……….. respiration whereas Amoeba undergoes………….. respiration.
(e) Gills are the breathing organs in…………..

Q 21.

Define breathing. State the differences between breathing and respiration.

Q 22.

What is compensation point?

Q 23.

Where does digestion begin?

Q 24.

What is the name given to the process of using the absorbed food for producing energy?

Q 25.

Why is small intestine in herbivores longer than in carnivores?

Q 26.

Mention the major events during photosynthesis.

Q 27.

Draw a diagram of human excretory system and label renal artery and urethra.
State in brief the function of :

  1. renal artery
  2.  kidney
  3.  ureter
  4. urinary bladder

Q 28.

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 29.

Which is the basic requirement of living organisms for obtaining energy ?

Q 30.

Name one organism each having saprophytic, parasitic and holozoic modes of nutrition.

Q 31.

(a) Name a gas used in photosynthesis.
(b) Name a gas produced in photosynthesis.

Q 32.

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

Q 33.

From which part of the body, undigested food is egested in Amoeba ?

Q 34.

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

Q 35.

Which of the organs perform the following functions in humans ?
(i) Absorption of food
(ii) Absorption of water

Q 36.

What is the other name of food pipe ?

Q 37.

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 38.

(a) What is common for Cuscuta, ticks and leeches ?
(b) Name the substances on which the following enzymes act in the human digestive system :
(i) Trypsin (ii) Amylase (iii) Pepsin (iv) Lipase
(c) Why does absorption of digested food occur mainly in the small intestine ?

Q 39.

Do all cells use oxygen to produce energy ?

Q 40.

Name the red pigment which carries oxygen in blood.

Q 41.

Which gases are exchanged in your lungs ?

Q 42.

What is the name of tiny air-sacs at the end of smallest bronchioles in the lungs ?

Q 43.

Name the type of respiration in which the end products are :
(a) C2H,OH and C02
(b) C02 and H20
(c) Lactic acid
Give one example of each case where such a respiration can occur.

Q 44.

Name the pigment, which can absorb solar energy.

Q 45.

In which kind of respiration is more energy released?

Q 46.

What are (i) stomata and (ii) lenticels?

Q 47.

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

Q 48.

How do the guard cells regulate opening and closing of stomatal pores?

Q 49.

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

Q 50.

Explain the role of mouth in digestion of food.