Short Answer TypeWith the help of an algebraic equation, how did Hardy-Weinberg explain that in a given population the frequency of occurrence of alleles of a gene is supposed to remain the same through generations?
Although a prokaryotic cell has no defined nucleus, yet DNA is not scattered throughout the cell. Explain.
Select and write analogous structures from the list given below:
(i) Wings of butterfly and birds
(ii) Vertebrate hearts
(ii) Tendrils of bougainvillaea and Cucurbita
(iv) Tubers of sweet potato and potato
How has the use of Agrobacterium as vectors helped in controlling Meloidogyne incognita infestation in tobacco plants? Explain in the correct sequence.
A nematode Meloidogyne incognita infects the roots of tobacco plants and causes a great reduction in yield. A novel strategy was adopted to prevent this infestation which was based on the process of RNA interference (RNAi).
Using Agrobacterium vectors, nematode-specific genes were introduced into the host plants. The introduction of DNA was such that it produced both sense and antisense RNA in the host cells. These two RNA’s being complementary to each other formed a double-stranded (dsRNA) that initiated RNAi and thus, silenced specific mRNA of the nematode.
The consequence was that the parasite could not survive in a transgenic host expressing specific interfering RNA. The transgenic plant, therefore, got itself protected from the parasite.
“India has greater ecosystem diversity than Norway.” Do you agree with the statement? Give reasons in support of your answer.
Write the difference between genetic biodiversity and species biodiversity that exists at all the levels of biological organisation.
Explain the mechanism of ‘sex determination’ in birds. How does it differ from that of human beings?
Organic farmers prefer the biological control of diseases and pests of the use of chemicals for the same purpose. Justify.
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