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How do organisms reproduce Cheat Sheet (DRAFT) by

NCERT: Grade x:biology :how do organisms reproduce

This is a draft cheat sheet. It is a work in progress and is not finished yet.

parts of a flower

The green outermost circle of a flower is called sepals. all sepals together are called calyx.
The function of sepal is to protect the flower in it's initial stages in it
The colourful part of a flower is called a petal. Petals together are called carolla
The function of petal is to attract insects
It is the male reprod­uction part of the flower. A single flower may have number of stamens in it.
i)Filament:-The filament is a long stalk-like structure which supports the anther.
ii)Anther:-It is a bilobed structure containing two pollen sacs present at tip of stamen . These produce pollen grains that are yellowish in colour.
Produce pollen grains.
It is the female reprod­uctive part, which is present in the center of the flower. It comprises of mainly three parts
(i)Stigma: It is the terminal part of the carpel which may be sticky. It helps in receiving the pollen grains during pollination.
(ii) Style: It is the middle elongated part of the carpel. It helps in the attachment of stigma to the ovary.
(iii)Ovary: the swollen bottom part of the carpel. It contains ovules having an egg cell (female gamete)
1) It is the female reprod­uctive part of the flower, and therefore it is involved in the fertil­ization process.
2) The stigma of the pistil is respon­sible for receiving the pollen.
3) The style of the pistil is respon­sible for safely transp­orting the compatible pollen to the ovule.
4) Pistil protects the ovule present inside it.


Fission is the process of division of a single unicel­lular organism into two or more organisms which then separately grow into two or more individuals
a)binary fissio­n:when a single unicel­lular organism divides into two new indivi­dua­ls,­first by nuclear division then by cytopl­asmic divisi­on,it is called binary fissio­n.O­ccurs in favorable conditions
b)multiple fission is the division of a single unicel­lular organism into multiple organi­sms.Occurs in unfavo­rable condit­ions.


In budding, a small part of an organism grows out as 'bud' which then detaches and forms a new organism

parts of a flower

male reprod­uctive parts

female reprod­uctive parts



The breaking up of a body of a simple multic­ellular organism into two or more pieces on maturing which subseq­uently forms a new organism is called fragme­ntation

vegetative propag­ation

it is a process by which a new plant can be obtained from vegetative plant parts such as roots steam or leaf

germin­ation of pollen grains

Pollin­ation: The transfer of pollen grains from the anther of the stamen to the stigma of a flower is termed pollin­ation.
Self-p­oll­ination: pollen from the stamen of a flower is transf­erred to the stigma of the same flower.
Cross pollin­ation: pollen from the stamen of a flower is transf­erred to the stigma of a different flower.


it is the ability of a fully differ­ent­iated organism to regenerate the whole body from its body parts. It doesn't occur in normal condit­ions. it is carried out by specia­lized cells that prolif­erate and undergo changes

spore formation

In spore formation, the parent plant produces hundred of micros­copic reprod­uctive units called spores. When the spore case of the plant burst, then the spore spread to the air, where these airborne spore land on soil, and under favorable condit­ions, they germinate into new plants.


After fertil­iza­tion, the zygote divides many times and forms an embryo within the ovule. This ovule then develops a tough coat and gets converted into a seed. The ovary rapidly grows and ripens as fruit. The seed contains the future embryo and develops into a seedling under suitable condit­ions. This process is called germin­ation.