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) 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 ?
Apart from sunlight and chlorophyll, what other things are required to make food by photosynthesis ?
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.
State whether the following statements are true or false :
(a) During respiration, the plants take C02 and release 02.
(b) Energy can be produced in cells without oxygen.
(c) Fish and earthworm exchange gases during respiration in the same way.
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
(a) What are heterotrophs ? Give one example of heterotrophs.
(b) What is the difference between autotrophic nutrition and heterotrophic nutrition ?
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 three common features of all the respiratory organs like skin, gills and lungs.
What are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.
(a)Explain how does the exchange of gases occur in plants across the surface of stems, roots and leaves.
(b) How are water and minerals transported in plants ?
In mammals and birds why is it necessary to separate oxygenated and de-oxygenated blood ?
Draw a neat diagram of excretory system of human beings and label on it:
(i) Left kidney (ii) Urinary bladder
In addition to carbon dioxide and water, state two other conditions necessary for the process of photosynthesis to take place.
What is the name of those cells in the leaf of a plant which control the opening and closing of stomata?
(a) Photosynthesis converts energy X into energy Y. What are X and Y ?
(b) State the various steps involved in the process of photosynthesis.
a) How do plants obtain food ?
(b) Why do plants need nitrogen ? How do plants obtain nitrogen ?
(a) What is the role of hydrochloric acid in our stomach ?
(b) What is the function of enzymes in the human digestive system ?
(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 ?
(a) Why is small intestine in herbivores longer than in carnivores ?
(b) What will happen if mucus is not secreted by the gastric glands ?
(c) What causes movement of food inside the alimentary canal ?