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.
(a) Homologous organs or structures are those that are similar in anatomy or structure and have a common origin, but perform different functions.
From the given options, following are homologous structures:
i. Forelimbs of whales and bats are similar in structure but perform different functions of swimming and flying, respectively.
ii. Thorns of Bougainvillea and tendrils of Cucurbita are both modifications of a stem arising from axillary bud but perform different functions of protection (thorns) and climbing (tendrils), respectively.
(b) The evolution represented by homologous organs or structures is divergent evolution as they have a common origin but have diverged (became dissimilar) with time into different structures performing different functions.
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.
Switch
