Question

Identify the given structures and select the correct option.

• A. (L) - Aplanospore of Ulothrix, (M) - Prothallus (2n) of pteridophyte, (N) - Ovule of angiosperm
• B. (L) - Palmella stage of Ulothrix, (M) - Prothallus (n) of bryophyte, (N) - Ovule of gymnosperm
• C. (L) - Akinetes of Chlamydomonas, (M) - Sporophyte (2n) of bryophyte, (N) -Endosperm of gymnosperm
• D. (L) - Palmella.stage of Chlamydomonas, (M) - Prothallus (n) of pteridophyte, (N) - Ovule of gymnosperm

Answer 1

Answer: (D)

(L) - Palmella.stage of Chlamydomonas, (M) - Prothallus (n) of pteridophyte, (N) - Ovule of gymnosperm

Figure L shows palmella stage in Chlamydomonas. In Chlamydomonas, under unfavourable conditions during zoospore formation, the daughter protoplast is not liberated and the parent cell wall- gets gelatinised. As a result, these protoplasts get embedded in the mucilage thus formed. This stage is known as palmella stage. It helps the zoospore to survive during unfavourable conditions. When the favourable conditions return, the mucilage dissolves and the daughter protoplasts form zoospores. Figure M is of gametophytic protha II us of pteridophytes. The prothallus is green, photosynthetic, independent, formed by germination of spores and bears antheridia and archegonia. Figure N represents L.S. ovule of gymnosperms. It shows haploid female gametophyte (or endosperm), bearing archegonia, micropyte, integuments, etc.

So the correct option is D.