Is nutrition' a necessity for an organism? Discuss.
Food is required for the following purposes:
(i) It provides energy for the various metabolic processes in the body.
(ii) It is essential for the growth of new cells and repair or replacement of worn out cells.
(iii) It is needed to develop resistance against various diseases.
(a) What are heterotrophs ? Give one example of heterotrophs.
(b) What is the difference between autotrophic nutrition and heterotrophic nutrition ?
(a) Name the pigment in leaves which absorbs sunlight energy.
(b) What is the colour of this pigment ?
Name the enzyme present in human saliva. What type of food material is digested by this enzyme ?
Name the substance whose build up in the muscles during vigorous physical exercise may cause cramps.
Write correct sequence of four steps of method for the preparation of temporary mount of a stained leaf peel.
In mammals and birds why is it necessary to separate oxygenated and de-oxygenated blood ?
In the experiment "Light is essential for photosynthesis", why does the uncovered part of the leaf turn blue-black after putting iodine solution?
In addition to carbon dioxide and water, state two other conditions necessary for the process of photosynthesis to take place.
Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?
Define (i) saprophytic nutrition (ii) parasitic nutrition, and (iii) holozoic nutrition. Give one example of each type.
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.
In the lungs :
(a) what substance is taken into the body ?
(b) what substance is removed from the body ?
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).
State the role of the following in human digestive system :
(i) Digestive enzymes (ii) Hydrochloric acid (iii) Villi
(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?
Name the intermediate and the end products of glucose breakdown in aerobic respiration.
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
(a) What is chlorophyll ? What part does chlorophyll play in photosynthesis ?
(b) (i) Which simple food is prepared first in the process of photosynthesis ?
(ii) Name the food which gets stored in plant leaves.
(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.
(a) How does carbon dioxide from the air enter the leaves of a plant to be used in photosynthesis ?
(b) How does water from the soil reach the leaves of a plant to be used in photosynthesis ?
(a) What is the role of hydrochloric acid in our stomach ?
(b) What is the function of enzymes in the human digestive system ?
(a) Define nutrition. Why is nutrition necessary for an organism ?
(b) What are the different modes of nutrition ? Explain with one example of each mode of nutrition.
(c) Name the mode of nutrition in (i) roundworm, and (ii) Plasmodium.