Sexual Reproduction in Flowering Plants Test - 77

Agamospermy is a type of asexual reproduction in which plant propagation occurs by means of apomictic seeds (or asexual seeds). In Apomixis there is seed formation without the fusion of gametes (syngamy) i.e., an embryo is formed within the seed coat without syngamy. In agamospermy, one or more sporophytic cells undergo stages of embryogeny and eventually grow into the mature embryo. Agamospermy is further divided into two categories: Gametophytic Apomixis and Sporophytic Apomixis. In gametophytic apomixis, an embryo is formed from unreduced female gametophyte i.e., embryo sac which is diploid because it is unreduced i.e., it didn't undergo meiosis. Sporophytic apomixis is also known as adventive embryony in which embryo is formed directly from the diploid sporophytic cells of the ovule such as Integuments and Nucellus. These diploid sporophytic cells undergo stages of embryogeny and then develop into the mature embryo which may sometimes result in the formation of more than one embryo within the same seed and thus, is called adventive polyembryony. 

So, the correct answer is C.

Agamospermy is a type of asexual reproduction in which plant propagation occurs by means of apomictic seeds (or asexual seeds). In agamospermy, one or more sporophytic cells undergo stages of embryogeny and eventually grow into the mature embryo. Agamospermy is further divided into two categories: Gametophytic Apomixis and Sporophytic Apomixis. In gametophytic apomixis, an embryo is formed from unreduced female gametophyte i.e., embryo sac which is diploid because it is unreduced, i.e., it didn't undergo meiosis. Sporophytic apomixis is also known as adventive embryony in which embryo is formed directly from the diploid sporophytic cells of the ovule such as Integuments and Nucellus. These diploid sporophytic cells undergo stages of embryogeny and then develop into the mature embryo.

So, the correct answer is C.

Salvia genus belongs to family Labiatae. In these plants, the gametopetalous corolla is two-lipped. The lower lip provides the platform for the visiting insect and the upper lip just protects the floral organs. In these plants, cross-pollination occurs only when the pollen-dusted bee visits older flowers with mature gynoecium.

So, the correct answer is option B.

So, the correct answer is option A.

Pollination is the transfer of pollen from the anther to stigma. By pollination, male gamete i.e. pollen is brought in contact with the female gamete i.e. egg. In Angiosperms, male and female gametes are present in the flowers. Pollination occurs by means of wind, water, insects, birds etc. In gymnosperms, male and female gametes are present on separate plants in the form of cones. Pollens are usually carried away by the wind to the female cones. Hence, pollination occurs in both Angiosperms and Gymnosperms.

So, the correct answer is C.

Apomixis is a kind of asexual reproduction in which viable embryo is formed within the confines of the seed coat, without meiosis and syngamy. Apomixis includes adventive embryony in which there is a formation of embryo due to sporophytic budding. One or more diploid sporophytic cells, either nucellus or integuments undergo stages of embryogeny and eventually develop into mature embryos. Amphimixis, on the other hand, is a kind of sexual reproduction which involves meiosis and syngamy. Hence, nucellar embryos are produced by apomixis and such embryos are diploid.

So, the correct answer is D.

Pollination which occurs by means of water is called hydrophily.

Pollination which occurs by means of air or wind is called anemophily.

Pollination which occurs by means of insects is called entomophily.

Worms are actually not pollinators. They help in increasing soil fertility.

So, the correct answer is B.