(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.
(a) The raw materials for photosynthesis are carbon dioxide and water. The green plants take carbon dioxide from air for photosynthesis. The carbon dioxide gas enters the leaves of the plants through the stomata present on their surface. The water required by the plants for photosynthesis is absorbed by the roots of the plants from the soil through the process of osmosis. The water absorbed by the roots is transported upwards through the xylem vessels to the leaves where it reaches the photosynthetic cells and utilized in photosynthesis.
(b) The conditions for photosynthesis are sunlight, chlorophyll, carbon dioxide and water.
(c) Factors affecting the rate of photosynthesis are
(i) Light
(ii) Carbon dioxide
(iii) Water
(iv) Temperature
(v) Mineral elements.
What is the name of tiny projections on the inner surface of small intestine which help in absorbing the digested food ?
State the three common features of all the respiratory organs like skin, gills and lungs.
Draw a neat diagram of excretory system of human beings and label the following:
(i) Kidney
(ii) Ureter
(iii) Urinary Bladder
(iv) Urethra
(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
Which of the organs perform the following functions in humans ?
(i) Absorption of food
(ii) Absorption of water
What is the name of the opening in the human body through which undigested food is thrown out ?
(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.
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…………..
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 ?
State the role of the following in human digestive system :
(i) Digestive enzymes (ii) Hydrochloric acid (iii) Villi
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?
All the animals can be divided into three groups on the basis of their eating habits. Name the three groups.
(a) What is the role of hydrochloric acid in our stomach ?
(b) What is the function of enzymes in the human digestive system ?
(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 ?
Name the substance whose build up in the muscles during vigorous physical exercise may cause cramps.
