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प्रश्न
What are the causes for the extinction of animals?
उत्तर
- Forests are destroyed for human needs.
- More animals are hunted for their horns, skin, teeth, and many other valuable products.
- Pollutions like air pollution and water pollution affect the animals.
- Sometimes animals are taken to new habitats by people. They cannot survive there.
- Pesticides and chemicals are used to get rid of insects, pests, or weeds, poison the plants and animals.
- Natural disasters like floods, cyclones, and fire also destroy animals.
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संबंधित प्रश्न
State the importance of DNA copying.
Why are budding, fragmentation and regeneration, all considered to be asexual type of reproduction?
Asexual reproduction is :
(a) a fusion of specialised cells
(b) a method by which all types of organisms reproduce
(c) a method producing genetically identical offspring
(d) a method in which more than one parent are involved
Reproduction is essential for living organisms in order to ______
Name two animals which undergo external fertilisation.
Fill in the following blank with suitable word :
The union of a sperm nucleus with an egg nucleus is known as.......... and results in a .........egg.
State whether the following statement is true (T) or false (F):
Most organisms have the capacity of regeneration in some or the other way.
Differentiate between the following:
Asexual reproduction and sexual reproduction.
Name the factors which take part in this process.
Which of the following types require pollinator but the result is genetically similar to autogamy?
The single shield-shaped cotyledon in monocot seed is known as ______.
Explain heterostyly and herkogamy with suitable example.
Nebenkern is ______.
What will happen if you cut planaria into small fragments?
Identify the chromosome number of the endosperm in the following case. In an angiosperm a female plant having 2n = 24 is crossed with a male plant having 2n = 12.
Explain the term reproduction.
In a flower, the parts that produce male and female gametes (germ cells) are
Which of the following nucleus is unlike other nuclei in the female gametophyte of angiosperms?
The statement ‘nothing lives forever, yet life continues’ illustrates the role of ______.
