Exercise
V. Why do organisms need to take food?
A. Distinguish between a parasite and a saprotroph.
3. How would you test the presence of starch in leaves?
Answers
Answer:
for getting energy and maintenance of body organisms need to take food .
Answer:
All living organisms require food to survive. It gives them energy to perform various activities. All activities such as playing, running, walking, studying, etc. require energy. The various components present in our food such as carbohydrates, proteins, fats, vitamins, and minerals provide energy to our body. These are also important for growth and development of the body.
Question 2:
Distinguish between a parasite and a saprotroph.
ANSWER:
Parasite
Saprotroph
The organism that grows on the body of another organism and derives nutrients from it is known as a parasite.
The organism that obtains nutrients from the dead or decaying organic matter is called saprotroph.
Examples of parasites are Cuscuta and orchids.
Examples of saprotrophs are fungi and some bacteria.
Question 3:
How would you test the presence of starch in leaves?
ANSWER:
Experiment to test the presence of starch in leaves:
Take two healthy green potted plants of the same type. Keep one potted plant in a dark room for one or two days in order to remove all the starch from the leaves. Keep the other plant in sunlight. Now, take one leaf from each potted plant and put a few drops of iodine solution on them.
Plants kept in light and dark conditions
No blue black colour will be observed on the leaves of the plant kept in the dark room. This indicates the absence of starch. Blue black colour will be observed on the leaves of the plant kept in sunlight. This indicates the presences of sunlight