What is reproduction? Why living beings reproduce?

The method of reproduction which takes place from a single parent without the fusion of male and female gamete is called reproduction.
The basic features of asexual reproduction are:
        - In asexual reproduction, only single organisms is involved.
        - It is easy and rapid method of reproduction.
        - The off springs produced are genetically identical.
       ...

Fission is the method of asexual reproduction in which a mother organism divides into two or more daughter organisms.
Any two types of fission are:
        - Binary fission.
        - Multiple fission.

The method of asexual reproduction which takes place by the formation of a bud is called budding.
Any two organisms that reproduce by this method are:
        - Yeast
        - Hydra

The method of asexual reproduction that takes place by means of spores is called sporulation.
The fact that amoeba reproduce by fission means amoeba itself divides into two or more daughter amoeba for its reproduction.

The method of asexual reproduction in which multicellular organisms breaks into two or more fragments and each fragments develop into new complete organism.
Any two organisms that reproduce by regeneration are:
        - Planaria
        - Tapeworm

The method of asexual reproduction in which new plants are produced by cutting, sowing or grafting of the vegetative parts of a plant like root, stem or leaf is called vegetative propagation.
The advantages of artificial vegetative propagation are:
        - Plants that do not produce viable seeds are propagated by this method.
        - It is cheaper, easier and faster method of reproduction.
 ...

The fission in which a single parent divides into two daughters is called binary fission.
Multiple fission is the method of asexual reproduction in which a parent organism splits into more than two daughter organisms at the same time. The nucleus of plasmodium first divides as into many nuclei and each nuclei are produced as daughter plasmodiums. In this way, plasmodium reproduce by multiple fission.

Tissue culture or micropropagation is a modern technique of producing new plants from isolated plant cells or a small piece of plant tissue in a culture solution.
The method of asexual reproduction in the given organisms are:

a.    Yeast:
        - Budding
b.    Rose:
        - Vegetative propagation
b.    Hydra:
       ...

The significance of asexual reproduction are:
        - It produces new individuals with exactly identical qualities as the parent.
        - It is a faster, easier and cheaper method of reproduction.
        - It reproduces the daughter plants which yields faster.
        - It helps to reproduce the plants which don't produce viable seeds.

It is the natural vegetative propagation arial stem.
It is beneficial for farmers because:
        - It is cheaper, easier and faster method of reproduction.
        - Large number of plants can be propagated by this method.
        - Plants who don't produce the viable seeds can be reproduced by it.
        - Plants reproduced by this method starts yielding faster.
...

The process in which reproduction take place by the fusion of a male and female gamete is called sexual reproduction.
The basic features of sexual reproduction are:
        - Both male and female organisms are involved in sexual reproduction.
        - Male and female produces their respective gametes which are formed due to meiosis.
        - A male and female gamete fuse to form a...

We know, flowering plants bears flowers that consists of androecium, gynoecium, sepes and petals. After the flower is fully developed, pollen grains get matured in the anther of flower. Due to different natural factors it is transferred from anther to stigma. As soon as it reach the ovule, it is fused with female gamete to form a zygote. The zygote develops into fruits and seeds. The developed seed germinate into new baby plant of same...

Pollination is the process of transfer of pollen grains from anther to stigma of a flower.
The difference between self pollination and cross pollination are:

Fertilization is the process of fusion of male and female gamete to form a zygote.

a.    Binary and Multiple fusion.

b.    Sperm and Ovum.

c.    Ovum and...

Layering is the artificial method of reproduction in which roots are developed on the stem while the stem is still attached to the parent plant.
The various method of layering are:
        - Simple layering.
        - Compound layering.
        - Tip layering.
        - Mound layering.
        - Air layering.

Mound layering is the typical propagation technique in which the original plants are set in the ground with the stem nearby horizontal, which forces side buds to grow upward.
For air layering, the target region of the stem is wounded, or a strip of bark is removed and then encased in a moisture retaining medium. Rooting hormone is often applied to encourage the growth of roots. The wounded portion develops into roots. Finally, the portion is separated from the parent plant to get new plant.

Grafting is the type of vegetative propagation in which a plant of superior quality is obtained by combining the root of a plant and shoot of other plant.
In whip grafting, the scion and the stock are cut slanting and then joined. The grafted point is then bound with tape or plastic and covered with soft wax to prevent dehydration and germs. The scion and stock combine within 2-3 months. Then the plastic tape can be removed.

Tongue grafting is the method of vegetative propagation in which the lower portion of the scion and upper portion of stock is cut obliquely to combine them together.

Tissue culture is done because:
        - To produce large number of off springs having similar features.
        - Adult plants can be produced in short time.
        - Many plantlets can be produced without seeds.

For tissue culture, a few cells of a plant to be propagated are taken and kept into a culture solution under sterile conditions. In this solution a sharpless lump is produced by rapid cell divisions of the plant cell. Then the lump or callus is transferred into another culture solution containing suitable plant hormones, which stimulate the callus to develop roots. This callus with root is transferred to other culture solution for its...

Name: Mother amoeba
Method: Binary fission

Name: Bryophyllm
Method: Vegetative propagation by leaf.

Name: Mother Hydra
Method: Budding

The organisms having only one kind of reproductive organ (either male or female) is called unisexual organism.
The organisms having both kind of reproductive organ is called bisexual organism.
For example:
Bisexual: Earthworm
Unisexual: Human beings

An embryo is a young plant or animal in the very early stage of development before birth or before coming out of its seed or egg.
It is produced by the mitotic cell division of a zygote in the early stage of is development.

The significance of sexual reproduction are:
        - It give continuity to the race.
        - It enables genetic variation which leads to evolution.
        - It increases the ability of adaptation.

We know, the sexual reproduction is such type of reproduction in which the exchange of heridity characteristics because of which entirely new kind of organism is developed. Due to that evolution and mutation occur, the newly developed off springs will be more powerful to be adapted in nature. All the plants and animals which we can see nowadays are the result of sexual reproduction. Due to the exchange of genes, there is more probability...

Sexual reproduction is not possible without meiosis cell division because meiosis cell division male and female gamete cannot be formed and sexual reproduction is impossible. So, meiosis cell division is essential in sexual reproduction.

Pea is bisexual plant i.e antherozoids and ovary mature at the same time and self pollination occurs. So, pea does not required external fertilization.

The small opening at the apex of the integument or in the way to egg from pollen tube is called micropyle.

It is found in gills of mushroom.

The plant of sub kingdom phanerogams have sexual reproduction because they are flowering plant as the flower has male and female reproductive cell or gametes.

The meaning of earthworm reproduce through regeneration is that when earth worm is broken into pieces the new young ones are produced from the broken parts.

The pollen grains can not formed when all the androecium  is removed immediately after the flower. The fruit is formed the ovary.

The plant is bryophyllum or begonia. This type of reproduction is known as vegetative propogation. There is no fusion of male and female gamete in this type of reproduction or there is no fertilization so, it is asexual reproduction.