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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.
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
What factors could lead to the rise of a new species?
Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
Name one reptile in given case where higher incubation temperature leads to the development of female progeny.
Which of the following represent tall plants and which represent short plants (or dwarf plants)?
(a) Tt
(b) tt
(c) TT
Give reason for your choice (The symbols have their usual meaning).
State one advantage of variation to a species.
How does the creation of variation in a species ensure its survival
Which of the following may be used to obtain an F2 generation?
(a) allowing flowers on a parent plant to be self-pollinated
(b) allowing flowers on an F1 plant to be self-pollinated
(c) cross-pollinating an F1 plant with a parent plant
(d) cross-pollinating two parent plants
Select the group which shares the maximum number of common characters.
Choose the one term from the following which includes the other three :
broccoli, wild cabbage, cauliflower, cabbage
Give two examples of plant species and two of animals.
How are those species which are now 'extinct' studied?
Will geographical isolation be a major factor in the speciation of a self-pollinating plant species? Give reason for your answer.
Define 'natural selection'.
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
List any two factors that could lead to speciation.
The process by which new species develop from the existing species is known as ______
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
