Sexual Reproduction in Flowering Plants Test - 50

Endosperm is a food laden tissue, surrounding the embryo on all sides or either present on one side of the embryo. It is of two types:
1. Non-endospermic or exalbuminous seeds
2. Endospermic or albuminous seeds.
In these seeds like pea, groundnut, the endosperm is completely consumed by the embryo, which belongs to the non-endospermous seeds category.

A megaspore mother cell is a diploid cell in plants in which meiosis will occur, resulting in the production of four megaspores. Therefore in the given example the diploid chromosome number is 24. 2n=24. Thus the number of chromosome in the endosperm is 12, because endosperm in gymnosperm is haploid.

Formation of endosperm which is triploid in nature in angiosperms will be found in monocarpellary, bicarpellary and polycarpellary condition.
Monocarpellary - only one single carpel present.
Bicarpellary - two carpels present
Polycarpellary - more than two carpels which include tetra carpellary, pentacarpellary and so on.

Apospory is defined as the development of a gametophyte directly from a sporophyte without the occurrence of meiosis or spore formation.

Gymnosperms are having a haploid endosperm. But, angiosperms have a triploid endosperm due to the double fertilization. The pollen grain is the haploid in nature. Therefore, in gymnosperms, the pollen grains and the megaspores are the haploids. The functional megaspores from the embryo sac. The endosperm is formed prior to the fertilization and hence it is haploid.

Sporopollenin is really a major element of the cruel outer exine walls associated with spores and pollen grains. It really is chemically very secure and is also usually well maintained in soils as well as sediments. The exine layer is usually intricately sculptured within species-specific designs, allowing material restored from lake sediments to supply useful information in order to palaeontologists about plant and also fungal populations before.

Palynology is the study of palynomorphs, mainly of spores and pollen grains. The spores of mosses and ferns are single-celled, while pollen grains of seed plants (gymno- and angiosperms) consist of two or three to several cells, all of them contained within the spore or pollen wall.

So, the correct answer is option A.

In gymnosperms, three of the four haploid spores produced in meiosis typically degenerate leaving one surviving megaspore inside the nucellus. The megagametophyte consists of around 2000 nuclei and forms archegonia, which produce egg cells for fertilization. Fertilization occurs within the archegonia produced by the female gametophyte. While it is possible that several egg cells are present and fertilized, typically only one zygote will develop into a mature embryo as the resources within the seed are limited.

Scutellum is part of the structure of a barley and rice seed - the modified seed leaf. The scutellum can also refer to the equivalence of a thin cotyledon in monocots. It is very thin with high surface area, and serves to absorb nutrients from the endosperm during germination. The scutellum is believed to contain an as yet unidentified protein transporter that facilitates starch movement from the endosperm to the embryo.

There are different types of pollination depending upon the agent involved in it. Pollination by bird is known as ornithophilous pollination. Chiropterophilous is a type of pollination in which pollination occurs by bats. Entomophilous is a type of pollination in which pollination occurs by insects. Pollination by snail and slug is known as malacophilous pollination.