Question

Find an odd one w.r.t. ploidy level in bryophytes-
A. NCC
B. VCC
C. Spore
D. Foot

Answer 1

Hint: Bryophytes is mostly considered an informal group. It consists of three divisions of embryophytes (non-vascular land plants): the liverworts, hornworts, and mosses. They are characteristically limited in size and prefer habitats with moisture although they can survive in much drier habitats. They consist of around 20,000 plant species.

Complete answer:
Some key points regarding Bryophytes-
• The term bryophyte is derived from the Greek word, Bryon "tree-moss, oyster-green" and, phyton meaning plant.
• Bryophytes do not produce flowers or seeds so they produce enclosed reproductive structures (gametangia and sporangia). They contain Neck canal cells (NCC) or Ventral Canal cells(VCC) and they are present in the archegonium(n).
Also, we all know that the life cycle of plants has two phases-
• Gametophyte(n)- It is the main plant body or dominant one.
• Sporophyte(2n)- It is reduced and dependent on sporophyte.
So, the ploidy level of gametophyte will be n and for that of sporophyte will be 2n.

If we know that the neck canal cells and ventral canal cells are a part of archegonium (multicellular a part of the female reproductive system) which is a part of Gametophyte(n) so it makes both the cells haploid too.
When we talk about spore, it forms through Sporophytes but after meiosis takes place then it becomes haploid.
The foot is also from sporophyte and hence it becomes diploid. So, if we check the ploidy level of the above three options then the only foot is diploid, and the rest all (NCC, VCC, and Spore) are haploid.

Hence, the correct answer is option (D).

Note: Some peculiar features of bryophytes are-
• The dominant stage is the gametophyte stage and the recessive stage is the Sporophyte stage.
• The sporophytes are not branched but they are unbranched.
• They are devoid of a true vascular tissue that contains lignin.