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.
Grey crescent is the area
at the point of entry of sperm into ovum
just opposite to the site of entry of sperm into ovum
at the animal poles
at the vegetal pole
The world's highly prized wool yielding 'Pashmina' breed is
sheep
goat
goat- sheep cross
Kashmir sheep- Afghan sheep cross
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
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
In a woody dicotyledonous tree, which of the following parts will mainly consist of primary tissues?
Stem and root
All parts
Shoot tips and root tips
Flowers, fruits and leaves
Animals have the innate ability to escape from predation. Examples for the same are given below. Select the incorrect example
enlargement of body size by swallowing air in puffer fish
melanism in moths
poison fangs in snakes
colour change in chameleon
According to IUCN red list what is the status of red Panda (Athurus fulgens)?
Vulnerable species
Critically endangered species
Extinct species
Endangered species
A man and a woman, who do not show any apparent signs of a certain inherited disease, have seven children (2 daughters and 5 sons). Three of the sons suffer from the given disease but none of the daughters are affected. Which of the following mode of inheritance do you suggest for this disease?
Autosomal dominant
Sex-linked dominant
Sex-limited recessive
Sex-linked recessive
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
