Answer:
A. Molecular changes such as extracellular signals on extracellular ligands can result in quick changes in cell behaviour. One example is insulin. Upon insulin binding on the receptor on the cell membrane, the cell release GLUT4 transporters (for muscle cells) to increase uptake of glucose.
B. Slow changes in cell behaviour can be observed for other lipophilic hormones or intracellular receptors such as glucocoortoid or estrogen which reacts with receptors in the cells.
C. Insulin is required to maintain a constant blood glucose level and hence levels of insulin has to be mediated in correspondence to the blood glucose levels. Fast acting signalling is thus required for homeostasis of blood glucose levels. Where for such lipophilic hormones such as steriods, glucocortoid, these hormones tend to have a longer lasting effect and hence results in a slow change.
The answer is B
Hope this helps
The tick is considered the vector in the chain of infection.
Generally, vector organisms are organisms that are capable of transmitting disease pathogens from infected organisms to uninfected ones either directly or indirectly as a result of their activities.
Ticks are parasites that feed on the blood of vertebrate animals such as deers and humans. When they feed on the blood of animals with certain infections, the pathogens for such infections are sometimes carried in the guts of the parasites and these are transferred to the bloodstream of the next animal that would be their host.
A good example of this is Lyme disease.
More about vectors can be found here: brainly.com/question/12596213?referrer=searchResults
Answer:
A new mutation
Explanation:
A mutation refers to the random changes in the DNA of organisms. A mutation changes the allele and genotype frequencies by the introduction of a new allele in the gene pool.
However, mutations are not the major factor responsible for changes in the gene pool of a population as mutations are rare. The rate of mutations is very slow and does not allow it to serve as a major factor to change the allele and genotype frequencies.
An allele is like a trait or a specific gene.
