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प्रश्न
State the various factors which could lead to the formation of new species.
उत्तर
The important factors which could lead to the formation of new species are:
(i) Geographical isolation of a population caused by various types of barriers
(ii) Genetic drift caused by drastic changes in the frequencies of particular genes, by chance alone
(iii) Variations caused in individuals due to natural selection.
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संबंधित प्रश्न
What is meant by speciation?
"Natural selection and speciation leads to evolution." Justify this statement.
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
Name the famous book written by Charles Robert Darwin.
Name five varieties of vegetables which have been produced from 'wild cabbage' by the process of artificial selection.
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
In the following Question, the Assertion and Reason have been put forward. Read the statements carefully and choose the correct alternative from the following:
Assertion: Speciation is the reproductive isolation amongst once interbreeding population.
Reason: Genetic drift, Natural selection, and Severe DNA change can cause speciation.
Add a note on allopatric speciation.
Arrange the major events as per geological time scale:
(Origin of conifers, Abundance of trilobites, Diversification of fishes, All types of marine algae, Formation of Forests, Rise of dinosaurs, Extinction of seed ferns, Rise of modern insects.)
| Geological time period |
Major events | |
| 1. | Cambrian | ______ |
| 2. | Devonian | ______ |
| 3. | Permian | ______ |
| 4. | Triassic | ______ |
