Long Answer Type(a) Name the primates that lived about 15 million years ago. List their characteristic features.
(b) (i) Where was the first man-like animal found?
(ii) Write the order in which Neanderthals, Homo habilis and Homo erectusappeared on earth.
State the brain capacity of each one of them.
(iii) When did modern Homo sapiens appear on this planet?
Short Answer Type(a) Select the homologous structures from the combinations given below :
(i) Forelimbs of whales and bats
(ii) Tuber of potato and sweet potato
(iii) Eyes of octopus and mammals
(iv) Thorns of Bougainvillea and tendrils of Cucurbita
(b) State the kind of evolution they represent.
Since the origin of life on the earth, there were five episodes of mass extinction of species.
(i)How is the 'Sixth Extinction', presently in progress, different from the previous episodes?
(ii)Who is mainly responsible for the 'Sixth Extinction''?
(iii)List any four points that can help to overcome this disaster.
How do homologous organs represent divergent evolution ? Explain with the help of a suitable example.
The organs with same structural design and origin but different functions are called. homologous organs
For example in plants the thorn and tendrils of Bougainuillea and Cucurbita represent homology. Both the thorn and the tendril have a common ancestor but have evolved to perform different function in different organism. Like the thorn has a protective function whereas the tendril provides support to the plant. Thus, it represents divergent evolution.
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