Question

In Funaria, 20 chromosomes are present in rhizoids, then the number of chromosome in calyptra, theca and foot will be:

• A. 20, 40, 40 respectively
• B. 40, 20, 20 respectively
• C. 20, 40, 20 respectively
• D. 40, 10, 20 respectively

Answer 1

Answer: (A)

20, 40, 40 respectively

1. Funaria is a kind of moss,which falls under Bryophyta in plant kingdom. Plants have two phases of life cycle that is Gametophytic phase(n) and sporophytic phase(2n).
2. In Bryophytes it is a haplo-diplontic phase where they alternates in between this two phases. That is the spore germinates to produce the plant body, and the gametes germinates to form a sporophytic body by germination.
3. In Mosses the dominant phase is gametophytic phase in which the plant body is produced.
4. Sporophyte is attached on gametophytes and gets its nourishment from here. Sporophyte has three divisions, foot, setae, capsule(spores are produced)
5. Here rhizoids have 20 chromosomes,which is the main part of plant body. As gametophytic phase is dominant here,so rhizoid is haploid.
6. Calyptra is a part of archaegonium which is a multicellular female sex organ of Bryophytes ,it will be haploid as it is a part of gametophyte.
7. Calyptra will have 20 chromosomes. Theca is a part of the sporophyte as is is the fertile part of the capsule.
8. So it will be diploid(2n) that is (2x20) 40 and foot is the part of sporophyte so it will be diploid that is 40.
   

So, the correct option is 'A'.