Question

A structure present in the ovule as well as the eggs of the birds is
(a) Integument
(b) Micropyle
(c) Chalaza
(d) Hilum

Answer 1

A structure common to both the ovule in plants and an egg of a bird is related to the embryo of both. It provides support and a path to supply nutrients to the embryo.

Complete step by step answer:
- The chalaza is a structure that is present in both plants in the ovule as well as birds in the egg.
- The chalaza in the egg are two spiral tissue structures that support the yolk in the albumen.
- The chalaza in the ovule is a segment where the nucellus and the integuments are joined. It is located across the micropyle end of the integuments. Nutrients in the ovule travel to the outer integument through the chalaza into the nucleus.

So, the correct answer is ‘Chalaza’.

Additional Information:
- The integument is present in plants and it is the covering of the ovule. It is perforated by the micropyle.
- An opening at the nucellus is present due to the integuments not closing completely around it, thus leaving a pore open. This is the micropyle. The pollen enters the ovule through the micropyle for fertilization.
- The hilum is a scar or mark left on the seed coat that indicates the previous attachment of it to the ovary wall or the funiculus.

Note:
- Chalaza is not present in the eggs of reptiles.
- In the egg, the chalaza is in close contact with the vitelline membrane.
- In the case of chalazogamy fertilization, the pollen tubes enter the chalaza instead of the micropyle.
- The chalazal cells in the ovule become antipodal cells during embryo sac development in fertilization.