Answer:
B) Polymerases can only synthesize in the 5' to 3' direction
Explanation:
The leading strand's directionality is 3' to 5', so polymerase has no problem with replicating this one. But the lagging strand has the opposite directionality, so the polymerase must work in the opposite direction of the replication fork.In consequence, the replication process undergoes periodic breaks, and the enzymes have to stop and start again while helicase separates both strands, resulting in the polymerization of okazaki fragments.
Answer:
Mutations in the HBB (beta-globin) protein causes symptoms of sickle cell disease.
That is binary fission, 'cause in this process, chromosome number doubles to it's original value whereas in meiosis it gets halved.
In short, Your Answer would be Option D
Hope this helps!
Natural changed to the ecosystem relate to environmental shock that occur naturally. Natural changes include floods, volcanic activity, hurricanes, etc. They can be destructive, but they also have advantages. Floods have the contribution of nutrients to the soil which was lacking. It can also relocate fishes and organisms living in bodies of water which improves the ecosystem.
<span>The answer is A. A stable ecological niche leads to the absence of selection pressures, which in turn causes species to remain unmodified or in stasis. This can be simplified with an example: If there are just enough lions on an island and just enough buck for both species to survive without the lions starving or the buck being killed off, neither of the species would have to adapt to survive because their predator-prey relationship is stable. This means that they can continue to live in this state of stasis or equilibrium. </span>
