Question

Seed habit is an important step in evolution. It is due to
(a)Heterogamy
(b)Heterospory
(c)Homospory
(d)Homogamy

Answer 1

Hint: Seed habit is an evolutionary process in vascular plants. In this the naked megasporangium got covered by a vascular integument and hence a seed was formed. It is the most advanced and successful method of sexual reproduction.

Complete answer:
Heterogamy is a condition in flowering plants where male and female parts of the flower are present in two different flowers. In simpler terms, we can say that a single plant has two types of flower – a male flower consisting of male reproductive part only and a female flower consisting of female reproductive part only.
Heterospory is the formation of two different types of spores by sporophytes of land plants. The spores formed are of different sizes. The larger one is known as megaspore and is female whereas, the smaller one is known as microspore and is male. These spores then develop into female and male gametophytes. They are common in pteridophytes. It is the most important evolutionary development in the plant as it leads to seed development.
Homospory or homosporous plants are those which are involved in the production of a single type of spore. The spores formed are of the same shape and size. It is most common in lower vascular plants. It is useful in long-distance dispersal of species. These plants do not produce seeds and the embryo formed derives its nutrition from green prothallus.
Homogamy is a condition in flowering plants where a flower contains both male and female parts. The anther and stigma of the flower both mature at the same time thus making it easy for pollination. This condition is also known as hermaphroditism.
So, the correct answer is ‘Heterospory’

Note: - The origin of seed habit is associated with the following:
Production of two types of spores (Heterospory), reduction in the number of megaspores finally to one per megasporangium, retention and germination of the megaspores and fertilization of the egg and continued development of the fertilized egg into the embryo while still in situ.