Tag: reproduction in higher plants

Collar like outgrowth arising from the base of ovule and forming a sort of third integument is known as aril. It is typically coloured, hairy and fleshy structure. It is edible in some of the species of plant. It helps in pollination as the insects gets attracted by its beautiful colour.

Endosperm develops after the formation of embryo. It functions as the nutritive tissue for the growing embryo. The endosperm is found as liquid (coconut water) and solid (coconut kernel, white fluffy part of maize). The endosperm found in maize is of nuclear type. 

In the case of coconut plant, the hard shell forms the inner layer of fruit (endocarp). Inside the shell, there is a seed which is covered by a seed coat. This seed coat is brown in colour and attached to the kernel which is endosperm. The seed coat is a thin layer which is protective in nature. 

Ethylene helps fruits ripen by making them softer, through the breakdown components of the cell walls, and sweeter, through the conversion of starches to sugars. Unlike the other plant hormones, ethylene is actually a gas and is distributed through the air, not through the plant body. One of the coolest things about ethylene is that it is released in a positive feedback loop, a little bit of ethylene causes more to be released, which causes even more to be released, and so on. A benefit of this fact is that you can take an unripe fruit (a pear, plum, or peach, for example) and put it in a paper bag with riper fruit (bananas work well for this) and ethylene will accumulate, making the unripe fruit soft and sweet. Indoleacetic acid, gibberellic acid and kinetin does not triggers the ripening process. 

Parthenogenesis is a type of asexual reproduction in which the offspring develops from unfertilized eggs. It is particularly common among arthropods and can also be found in some species of fish, amphibians, birds and reptiles, but not in mammals. 

Ovary get transformed into fruit post fertilisation. Outer layer of ovary becomes the outer layer of fruit along with ovules converting into seeds.

Ovules form into seeds in the mature fruit post fertilisation (transformed ovary). Their different arrangements can be seen in fruits such as pea, orange etc.

In almost all angiosperms, double fertilisation takes place where a triploid endosperm is formed. In a few cases, it is non - endospermous where the entire endosperm is consumed during the development of embryo.

Endosperm of angiosperm results when the secondary nuclei which is diploid fuses with the second sperm entering the apparatus, which is haploid in nature.