Which of the following is not vestigial in man?
Tail vertebrae
Nails
Nicitating membrane
Vermiform appendix
Presence of tail in a child is an example of
atavism
divergent evolution
convergent evolution
mutation
There are two opposing views about origin of modern man. According to one view Homo erectus in Asia were the ancestors of modern man. A study of variations of DNA however suggested African origin of modern man. What kind of observation on DNA variation could suggest this?
Greater variation in Africa than in Asia
Variation only in Asia and no variation in Africa
Greater variation in Asia than in Africa
Similar variation in Africa and Asia
C.
Greater variation in Asia than in Africa
There are two models about the origin of modern man (Homo sapiens):
(i) Multiregional model- As per this model, modern humans evolved in different parts of the model from regional descendents of Homo erectus who disapperared from Africa about 1- 2 mya (million years ago).
(ii) Monogenesis model- As per this model, African descendents of Homo erectus gave rise to modern humans.
According to an experiment by some scientists in late 1980s, mtDNA (mitochondrial DNA) of >100 people was studied from 4 different continents. Greater the difference between th mtDNAs of two people, the longer ago it diverged from a common source. They concluded that divergence of mtDNA of Africans began about 200,000years ago. Therefore, there are greater variation in Asia than in Africa.
In Ornithine cycle, which of the following wastes are removed from the blood?
Urea and urine
Ammonia and urea
CO2 and ammonia
CO2 and urea
Organs which differ in origin but perform similar functions
analogous
homologous
vestigial
all of these
Which one of the following phenomena supports Darwin's concept of natural selection in organic evolution?
Development of transgenic animals
Production of 'Dolly' the sheep by cloning
Prevalence of pesticide resistant insects
Development of organs from 'stem cells' for
organ transplantation
Which one of the following experiments suggests that simplest living organisms could not have originated spontaneously from non-living matter?
Microbes did not appear in stored meat
Larvae could appear in decaying organic matter
Microbes appeared from unsterilized organic matter
Meat was not spoiled, when heated and kept sealed in a vessel