Tag: pollen grain

Questions Related to pollen grain

Germ pore/ germinal furrow present on the surface of pollen grain represents

botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

  1. Area where exine is thin or absent

  2. Specialised thickening of exine

  3. Specialised thickening of intine

  4. Area where tectum is absent

Show answer
Correct Option: A
Explanation:
Pollen wall consists of two layers: outer layer exine and inner layer intine.
Exine is made up of sporopollenin which is one of the most resistant known biological materials. Exine is thin in the beginning but it becomes very thick with maturity. However, exine is discontinuous or ruptured at some places. These are the called the germ pores (or germinal furrow) through which pollen tube comes out during germination on the stigma.
So, the correct answer is A.

The innermost layer of the anther wall is tapetum which

botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

  1. helps in dehiscence

  2. provides mechanical support

  3. provides protection

  4. provides nutrition

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Correct Option: D
Explanation:
The tapetum is a specialized layer of nutritive cells found within the anther, of flowering plants, where it is located between the sporogenous tissue and the anther wall. Tapetum is important for the nutrition and development of pollen grains, as well as a source of precursors for the pollen coat.
So, the correct option is, 'provides nutrition'.

An organic substance which can withstand environmental extremes and which cannot be degraded by any enzyme is

botany male & female gametophytes: structure and development pollen grain androecium male gametophyte

  1. Sporopollenin

  2. Lignin

  3. Cuticle

  4. Cellulose

Show answer
Correct Option: A
Explanation:

An organic substance which can withstand environmental extremes and which cannot be degraded by an enzyme is sporopollenin. It is the substance present in the exine layer of pollen grains. Due to its presence, fossils of pollen grains can be found. 

So, the correct option is 'Option A'.