Question

Identify the pair of wrong statements in the following.
I) Intine of pollen grains is made up of sporopollenin.
II) Pollen grains are well preserved as fossils because of the presence of sporopollenin.
III) Enzymes can degrade the organic material of the exine of the pollen grains.
IV) Sporopollenin can withstand high temperature, strong acid and alkali.

A) III, IV
B) I, III
C) I, II
D) II, III

Answer 1

Hint:Pollen grains are the microscopic structures which carry the male reproductive cells of the plant. The pollen grains vary in shape and size depending on the plant species. Pollen contains both reproductive as well as vegetative parts.

Complete Answer:
The pollen grains have three parts-
Central cytoplasmic part- It contains nuclei which helps in fertilisation.
Intine or the inner layer- It contains cellulose and hemicelluloses. It can be easily broken down. (statement I is false)
Exine or the outer layer- It is the most durable layer which is resistant to disintegration. Treatment with intense heat, strong acids or strong base has little effect on it. The constituents of exine are called sporopollenins. The sporopollenin can be easily preserved in various kinds of sediments. (Statement III is false)
Statement II , IV are correct and I and III are wrong.

Thus the correct answer is option (B).

Note:The pollens are stable to decay due to the exine. This feature of pollens makes its widespread dispersal by wind and water possible. The pollen grains are found in geologic sediments due to which the history of the terrestrial plants can be found out.