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प्रश्न
Read the following statement and justify same in your own words with the help of suitable example.
Geographical and reproductive isolation of organisms gradually leads to speciation.
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उत्तर
- Every species survives in specific geographical conditions. The requirements of food and habitat, is specific for each species. Their reproductive ability and period is also different.
- Therefore, the individuals from one species cannot reproduce with individuals from other species.
- When they are separated by a distance or geographical barriers they are said to be isolated geographically.
- When they cannot reproduce with each other, they are said to be isolated reproductively.
- The ancestor species of both these subspecies may be the same but due to isolation over a very long time duration, there is genetic variation between the two. Therefore, the isolation leads to speciation.
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संबंधित प्रश्न
Explain the following:- Speciation
Name two human traits which show variation.
How does the creation of variation in a species ensure its survival
A plant with two 'small' genes breeds with a plant with two 'tall' genes to produce :
(a) small plants and tall plants in the ratio 1 : 3
(b) all small plants
(c) all tall plants
(d) tall plants and small plants in the ratio 3 : 1
Select the group which shares the maximum number of common characters.
What name is given to the sequence of gradual changes over millions of years in which new species are produced?
Name an animal having rudimentary eyes.
Give an example of characteristics being used to determine how close two species are in evolutionary terms.
With the help of an example, explain how variation leads to evolution.
What is meant by a species?
Give two examples of plant species and two of animals.
Define 'speciation'. Explain how speciation occurs.
The human species has genetic roots in ______
Which of the following statement is incorrect with respect to variations?
(a) all variations in a species have equal chance of survival
(b) change in genetic composition results in variations
(c) selection of variations by environmental factors forms the basis of evolutionary process
(d) variations are the minimum in asexual reproduction
According to the evolutionary theory, the formation of a new species is generally due to ______
Define Speciation.
In human males, all the chromosomes are paired perfectly except one. These unpaired chromosomes are ______
(i) Large chromosome
(ii) Small chromosome
(iii) Y chromosome
(iv) X chromosome
Add a note on allopatric speciation.
