Question

In the fern, fertilization takes places when ________.

A. moisture is present

B. spores reach the eggs within the archegonia

C. sperm swim in external water to the antheridia

D. conditions are dry enough

E. an insects can provide pollination

what two groups produce seeds?

A. gymnosperms and angiosperms

B. bryophytes and ferns

C. bryophytes and gymnosperms

D. angiosperms and fern

E. angiosperms and bryophytes

Answer 1

1. Option A. Fern fertilizes only in the presence of water. This is because, the sperm ( from the antheridia) needs to reach to the archegonium in which the egg is present. The sperm swims through the external water and reaches the archegonium to fertilise the egg. Since water is essential for this purpose, fern fertilizes only when there is moisture.

All other opttions are wrong. Option B is wrong because, It is not the spore is reaching the archegonium. The spore germinates to a gametophyte. Inside the gametophyte, both egg (inside archegonium) and sperm (inside antheridium) are present. The sperm is the structure that reaches the archegonium to fertilize the egg. Option C is wrong because the sperm is not moving to antheridium, but to the archegonium. Other options are wrong because fertilization at dry condition and insect pollination are absent in ferns.

2. Option A- Gymnosperms and angiosperms.

In these two plant groups only seeds are produced. Because, here after the process of fertilization ovule is developed to the seed, inside which the embryo is present. Seed in gymnosperm is naked, but that of angiosperm possess fruit which encloses the seed. The other lower groups lack seed formation because they are not flowering plants. Ovary and ovle is the part of. carpel, which is the female reproductive structure of flowering plants. The seed is developed from ovule and fruit from the ovary. Since flowering is absent in lower groups they lack seed formation.