When mosquitoes are abundant, purple martins flock to the area and feed exclusively on them. When mosquito populations are not large, purple martins are similarly scarce and feed on other insects. This is an example of A) density-independent regulation. B) density-dependent regulation. C) ecosystem carrying capacity. D) community carrying capacity.

Density-dependent regulation

Explanation:

density-dependent processes takes place when the density of a population population regulate growth rates.

Some factors that affect density-dependent factors could be biotic (biological in nature), such as;disease, predation, intraspecific competition, accumulation of waste, and interspecific compitition.

For instance, in interspecific competition or intraspecific compitition, reproductive rates of the individuals will definitely reduced,which results to reduce in population’s growth rate.When the prey density is low, the mortality of its predator is increased.

Therefore,when mosquitoes are abundant and purple martins flock to the area and feed exclusively on them, since the mosquito populations are not large, purple martins are similarly scarce and feed on other insects, this is reffered to as Density-dependent regulation.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.