Aresearcher introduces double-stranded rna into a culture of mammalian cells and can identify its location or that of its smaller subsections experimentally, using a fluorescent probe.

38) some time later, she finds that the introduced strand separates into single-stranded rnas, one of which is degraded. what does this enable the remaining strand to do?

a) attach to histones in the chromatin

b) bind to complementary regions of target mrnas

c) activate other sirnas in the cell

d) bind to noncomplementary rna sequences

The correct answer is B) binds to the complementary sequence of target mRNAs

Explanation:

Double stranded RNA can be used to block the expression of target mRNAs.

      At first the introduced double stranded RNA is being separated into  single stranded RNAs .One of the Single stranded RNA is degraded.

        The remaining Single stranded RNA binds to the target mRNA by complementary base pairing and blocks the expression of that single stranded RNA.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.