Plant Reproduction Test - 3

Maize flower is pollinated by winds. The transfer of pollen grain from anther to stigma by wind is known as anemophilus.

Lotus is an aquatic plant but the flower of lotus is outside and above the water surface. So, it cannot be pollinated by water. It is generally pollinated by insects.

The transfer of pollen grain from anther to stigma is called pollination. Pollination is caused by winds, insects, water, and some other means. Insect pollinated flowers are called Entomophilous flowers .

About 60% of angiosperms, pollen grains are shed at two celled stage. The larger cell is called vegetative cell and the smaller one is called generative cell. Each generative cell produces two male gametes.

Anther is bilobed structure at the tips of stamen. Each lobe consists of two theca. Each theca change into microsporangium. Anther forms four sided structure having four microsporangia in which pollen grains are formed.

Endosperm is present around the growing embryo. It provides nutrition to the growing embryo. In leguminous plants, it is completely consumed by the embryo and nothing remains in seed as in pea.

PEN (primary endosperm nucleus) divides into two nuclei and subsequent division of nucleus produce large number of nucleus without cell wall formation. These types of endosperm are called free nuclear type of endosperm.

Double fertilisation involves fusion of one male gamete with egg during Syngamy and fusion of two polar nuclei with other male gametes. So, total 5 nuclei are involved in double fertilisation.

Maize grain is monocotyledonous, having a single cotyledon. This cotyledon is also called scutellum.

The correct option is  A  Epicotyl
Plumule- Shoot tip.

Radicle - Embryonic root.

A. Epicotyl- The portion of axis between the plumule and the cotyledonary node.

B. Hypocotyl- The portion of axis between the radicle and the cotyledonary node.

D. Coleoptile- Protective sheath of plumule.

So, the correct answer is 'Epicotyl '

The seedless fruit develops without fertilisation by using some plant hormones. The fruit so formed are called parthenocarpic.

Placenta is located inside the ovarian cavity. It help in transport of nutrient to megasporangium or ovule. Ovule is attached to placenta by means of stalk called funicle.

Seeds dispersed by water are contained in light and buoyant fruit, giving them the ability to float. Coconuts are well known for their ability to float on water to reach the land where they can germinate. The coconut seed is especially well adapted to increase its range by the method of ocean dispersal. The seed floats when its outer layers dry out. The buoyant coconuts drift on ocean currents and end up on tropical beaches where they germinate and take root.

• True Fruit : A true fruit is one that develops only from the ovary. 
  Example:  Mango, Coconut, Zizyphus etc.
• False Fruit or Pseudocarp:  In some fruits, it is not the ovary that forms the fruit. In fact, some other parts of the flower, like the thalamus, inflorescence, calyx are modified to become a part of the fruit. These types of fruit are called false fruits. 
  Example: Apple, Strawberry etc.

• Non motile pollen grains are carried to the female gamete via a pollen tube which extends from the stigma, all the way through the style, reaching the ovaries.
• Wind, water, insects, etc. are just ways of mode of transportation for cross pollination.