In eukaryotes, the DNA strands are linear, and DNA polymerase can't replicate the very ends of the DNA strands! These ends are "protected" by repeated sequences called "telomeres." Either the chromosome gets shorter with each replication, or else a special enzyme-nucleic acid complex called telomerase adds new telomeres to the ends. A prokaryotic chromosome is circular and thus does not have the problem of having ended.
<span>Eukaryotic DNA is wound around histones, coiled, and supercoiled -- to replicate it, there have to be unwinding mechanisms, and mechanisms to reduce the degree of coiling. In prokaryotes, the winding problem is much less, and there aren't any histones.</span>
Answer:
can ,synthesize specific proteins
Explanation:
Hormones are chemical signals secreted by animals and plant that are capable of regulating body activities and maintain homeostasis.
They are transported in the circulatory system of the body
The action of hormones can be seen after the hormone has bound to its specific receptor found inside the cell.
For instance, steroid hormone and the thyroid hormones can pass through the plasma membrane to their receptors inside the cells.
When they bind with their receptors, the target cells will synthesize specific proteins that produce the characteristic effect of the hormone.
Answer: Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Explanation:
Answer:
1. high adaptability
2. low population size
3. All the dinosaurs, along with 50% of all species alive at the time died out when an asteroid struck Earth.
Answer:
fur with black hairs
Explanation:
Its because B denotes the dominant gene which express itself and supress the recessive one (b)
