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प्रश्न
Define speciation according to A.E. Emerson and explain its types giving suitable examples.
उत्तर
A.E. Emerson defines species as a ‘genetically distinctive, reproductively isolated natural population’. Speciation is a fundamental process in evolution. If one species diverges to become two or more species it is cladogenesis or divergent evolution.
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संबंधित प्रश्न
List four factors responsible for speciation.
Name one reptile in given case where higher incubation temperature leads to the development of female progeny.
State one advantage of variation to a species.
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.
Give an example of characteristics being used to determine how close two species are in evolutionary terms.
Does geographical isolation of individuals of a species lead to the formation of a new species? Provide a suitable explanation for your answer.
One of the following has not been produced from wild cabbage by the process of artificial selection. This one is :
(a) kohlrabi
(b) cabbage
(c) spinach
(d) kale
List any two factors that could lead to 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 | ______ |
