(a) What is photosynthesis ?
(b) Write a chemical equation to show the process of photosynthesis in plants.
(c) Explain the mechanism of photosynthesis.
(a) The process by which green plants make their own food (like glucose) from carbon dioxide and water by using sunlight energy in the presence of chlorophyll is called photosynthesis.
(c) The process of photosynthesis takes place in the green leaves of a plant. The carbon dioxide gas required for making food is taken by the plant leaves from the air which enters the leaves through tiny pores called stomata. Water required for making food is taken from the soil which is transported to the leaves from the soil through the roots and the stem. The sunlight provides energy required to carry out the chemical reactions involved in the preparation of food. The green pigment called chlorophyll absorbs sunlight energy. The photosynthesis takes place in three steps:
(i) Absorption of sunlight energy by chlorophyll.
(ii) Conversion of light energy into chemical energy and splitting of water into hydrogen and oxygen by light energy.
(iii) Reduction of carbon dioxide by hydrogen to form carbohydrates like glucose by utilising the chemical energy.
Arrange the following processes involved in the nutrition in animals in the correct order (in which they take place):
Assimilation, Egestion, Ingestion, Absorption, Digestion
Name the enzyme present in human saliva. What type of food material is digested by this enzyme ?
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
Name the intermediate and the end products of glucose breakdown in aerobic respiration.
a) How do plants obtain food ?
(b) Why do plants need nitrogen ? How do plants obtain nitrogen ?
(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 ?
(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 ?
Name one substance which is produced in anaerobic respiration by an organism but not in aerobic respiration.
In the lungs :
(a) what substance is taken into the body ?
(b) what substance is removed from the body ?
Describe the process of respiration in the following parts of a plant :
(a) Root (b) Stem (c) Leaves
Why is the rate of breathing in aquatic organisms much faster than in terrestrial organisms ?
Draw a neat diagram of excretory system of human beings and label the following:
(i) Kidney
(ii) Ureter
(iii) Urinary Bladder
(iv) Urethra
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?
Which of the following type of energy is used by living organisms to perform vital life processes ?
Kinetic energy, Chemical energy, Potential energy, Nuclear energy
All the animals can be divided into three groups on the basis of their eating habits. Name the three groups.
