PRACTICE ASSIGNMENT: 3
SS-VII
Biology
What is autotrophic nutrition?
Name one plant each showing the following modes of nutrition:
(a)
Saprophytic
(b) Parasitic
(c) Insectivorous
What is the site of photosynthesis in green plants?
Answers
Answer:
Explanation:
→ Autotrophic nutrition means that simple inorganic substances are taken in and used to synthesise organic molecules. Energy is needed to achieve this. In photo-autotrophic nutrition light is the energy source. In most instances the light source is solar energy, the process being photosynthesis.
→ The mode of nutrition in which an organism obtains nutrients from dead and decaying organic matter is called saprophytic nutrition. Example - Rhizopus (bread mould), Mucor (pin mould), Yeast, Agaricus (mushroom) .
→ Examples of parasitic mode of nutrition are mosquito,ticks, lice, bedbugs , tapeworm.
→The insectivorous mode of nutrition is observed in plants like pitcher plant and the Venus fly trap.
→ The Cell. All green parts of a plant, including green stems and unripened fruit, have chloroplasts, but the leaves are the major sites of photosynthesis in most plants . It is the light energy absorbed by chlorophyll that drives the synthesis of food molecules in the chloroplast.