What does ‘S’ refer in a 70S | Class 11 Biology Chapter Cell: The Unit of Life, Cell: The Unit of Life NCERT Solutions

Define a taxon. Give some examples of taxa at different hierarchical levels.

What are the steps involved in formation of a root nodule?

Comment on the experimental setup
a. What does the setup demonstrate?
b. What will happen to the level of water if a blower is placed close to setup.
c. Will the mercury level fluctuate (go up/down) if phenyl mercuric acetate is sprayed on leaves?

Match the following
a. Amphibia                   i. Air bladder
b. Mammals                  ii. Cartilaginous notochord
c. Chondrichthyes         iii. Mammary glands
d. Ostichthyes               iv. Pneumatic bones
e. Cyclostomata            v. Dual habitat
f. Aves                          vi. Sucking and circular mouth without jaws.

Eukaryotic cells have organelles which may
a. not be bound by a membrane
b. bound by a single membrane
c. bound by a double membrane
Group the various sub-cellular organelles into these three categories.
 

Seeds of some plants germinate immediately after shedding from the plants while in other plants they require a period of rest before
germination. The later phenomena is called as dormancy. Give the reasons for seed dormancy and some methods to break it.

What is the role of feathers?

Distinguish between families Fabaceae, Solanaceae, Liliaceae on the basis of gynoecium characteristics (with figures). Also write economic importance of any one of the above family.

The glomerular filtrate in the loop of Henle gets concentrated in the descending and then gets diluted in the ascending limbs. Explain.
 

Write short notes on the functions of the following hormones,
(a) Parathyroid hormone (PTH)
(b) Thyroid hormones
(c) Thymosins
(d) Androgens
(e) Estrogens
(f) Insulin and Glucagon

Discuss the main steps in the digestion of proteins as the food passes through different parts of the alimentary canal.