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प्रश्न
Define ‘reproductive isolation’ and explain two types of reproductive isolation.
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उत्तर
Reproductive Isolation: Prevents interbreeding between the populations whether they are geographically isolation or living close together.
Types of Isolating mechanisms :
1. Pre -mating or pre-zygotic isolating mechanisms : In habitat Isolation, members of a population living in the same region occupy different habitat. Thus potential mates do not meet. In seasonal isolation, members of a population attains sexual isolation, members of a population attain sexual maturity at the different times, thus preventing interbreeding.
In ethological isolation, members of two populations have different mating behaviours. This prevents interbreeding.
In mechanical isolation, the members of two populations have differences in the structure of reproductive organs. So interbreeding is not possible.
2. Post-matting or post zygotic isolating mechanisms are : Gamete mortality (Sperms transfer takes place but egg is not fertilized), Zygote mortality (Egg is fertilized but zygote dies) and hybrid sterility (Hybrids are sterile)
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संबंधित प्रश्न
Identify the pre-human ancestor.
Name the ancestor of human nicknamed as Handyman
Describe modern man.
Complete the following paragraph with the words given in brackets.
(Cro-Magnon, brain, fire, agriculture, Cultural, homo-sapiens, wise man)
Evolution of upright man continued in the direction of developing its ________ for the period of about 1 lakh years and meanwhile it discovered the __________. Brain of a 50 thousand year old man had been sufficiently evolved to the extent that it could be considered as a member of the class _______. Neanderthal man can be considered as the first example of _______. The _______ man evolved about 50 thousand years ago and afterwards, this evolution had been faster than the earlier. About 10 thousand years ago, wise-man started to practice the _______. It started to rear the cattle-herds and established the cities. _______ development took place.
Identify the human ancestor which showed both ape-like and man-like characters.
Which was the first known hominid?
Identify the CORRECT sequence of evolution of modem man.
Identify the heavily built, short prehistoric man having cranial capacity of about 1400 cc who is known to bury the dead.
Who was more intelligent than modem man, cave-dweller, had prominent chin and appeared after Neanderthal man?
Name the following:
Scientific name of Handy man
