Category : 10th Class
A species is the organisms consisting of similar individuals, which can breed together and produce fertile off springs. The species can be man or other animals or crops plants. Thus the process of developing new species from the existing species is known as speciation. Normally the new species arises due to the variation, which passed from one generation to the next and get accumulated over the long period of time. This also happens when the population of same species splits up into two separate groups, which then get isolated from each other geographically by the barriers such as mountain ranges, river or the sea.
The main factors which could cause speciation are the geographical isolation, genetic drift caused by drastic changes in the frequencies of particular genes and the variations caused in individuals due to natural selection.
There is no real progress in the field of evolution, rather it is just the production of diversity of life forms and shaping of this diversity by the environmental selection. The only progress in the evolution which appears to us is that the organism with more and more complex body designs have emerged over the ages. It is not that with the appearance of organisms with complex body designs the simpler organisms will disappear. It depends on the environmental condition of the place. For example, one the simplest and primitive life forms called bacteria still inhibits in some of the most inhospitable habitats such as hot springs, deep sea, thermal vents and the ice in Antarctica.
Which one of the following sex chromosomes give rise to the male child?
(a) XX
(b) XY
(c) YY
(d) XYX
(e) None of these
Answer: (b)
Name the scientist who gave the theory of evolution.
(a) Darwin
(b) Lamarck
(c) Mendel
(d) Baptiste Pierre
(e) None of these
Answer: (a)
Which one of the following is not present in the darwins theory of evolution?
(a) Overpopulation
(b) Natural Variation
(c) Struggle for Existence
(d) Use and disuse of organ
(e) None of these
Answer: (d)
Which one of the following is more in common with us in terms of evolution?
(a) Chinese Boy
(b) Monkey
(c) A chimpanzee
(d) Bacteria
(e) None of these
Answer: (c)
You need to login to perform this action.
You will be redirected in
3 sec