Asexual reproduction in plants

Class 10 bio How do Organisms Reproduce?

How is DNA is important for reproduction?

DNA (Deoxyribo Nucleic Acid) molecules. The DNA in the cell nucleus is the information source for making proteins. If the information is changed, different proteins will be made. Different proteins will eventually lead to altered body designs.

Why simply pushing out the other copy don’t work?

Because the copy pushed out would not have any organized cellular structure for maintaining life processes. Therefore, DNA copying is accompanied by the creation of an additional cellular apparatus, and then the DNA copies separate, each with its own cellular apparatus. Effectively, a cell divides to give rise to two cells.

Why is the variation beneficial to the species but not necessarily for the individual?

If we consider that a change occurs in a species and some variations develop. Those variants may be able to cope with the change and have a chance of survival through the harsh condition. But the other members of the species will not survive. But in the same situation, if the variation occurs at an individual's level the individual may not cope up in that unsuitable environment and dies. So, we can say that variation is helpful at a species-level for evolution but at an individual's level, it is not necessarily beneficial.

Fission

Fission is a process by which a unicellular organism divides to form two or more daughter cells.

Multiple Fission

The splitting or division of a mother cell more than two daughter cells.

Can take place only in favorable conditions

Eg. Plasmodium, etc.

Binary fission

The splitting or division of a mother cell into two daughter cells.

Can take place even in unfavorable conditions

Eg. Amoeba, etc.

Fragmentation

where an organism breaks into fragments, and each fragment develops into a complete, independent organism

eg. Spirogyra

Regeneration

The ability to give rise to a new individual organism from the body parts if the individual is not cut or broken into many pieces.

Eg. Planaria

Budding

small projections called its bud grow on their parents body which day attaches once matured and develop into a new individual.

Eg. Budding etc.

Vegetative Propagation

new organisms that grow with the help of propagules

Grafting

a process in which a portion of one plant part is placed (scion) onto a portion of another plant (stock). It is the artificial method of vegetative propagation.

Layering

A branch of a plant is bent down and covered with soil. A cut is made on the parent plant which develops in a new individual.

Bryophyllum

buds produced in the notches along the leaf margin of Bryophyllum fall on the soil and develop into new plants

Spore Formation

A form of reproduction in which the reproductive bodies called the spores are present in a sac called the sporangia. Once these spores mature the sporangia burst and develop into matured new Rhizopus individuals