Answer:
No, CREs usually don't account for differences in gene expression levels.
Explanation:
<em>Cis</em>-regulatory elements (CREs) are non-coding DNA regions that regulate adjacent gene <em>transcription</em>. They usually do it by binding to transcription factors. They are in charge of influencing the rate of which transcription occurs, and less with how much a gene is expressed. On the other hand, trans-regulatory elements are DNA sequences that encode for upstream regulators that can modify or regulate <em>gene expression levels</em>.
Therefore, cis elements are not really in charge of expression levels, mostly transcription rates of single genes, rather. Trans elements are more involved in expression levels.
There is no difference in mental abilities between genders
Answer:
The correct answer is keystone predator.
Explanation:
In sustaining the composition of an ecological community, a keystone species plays an essential function. In the absence of keystone species, the ecosystem would fail to exist and would become drastically different. A predator is a classic illustration of a predator, which inhibits a specific herbivorous species from eradicating the dominant species of plants. In the non-existence of predators, the herbivorous prey would increase enormously and would clean the entire essential plant species, and thus, drastically change the significance of the ecosystem.
Answer:
A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA.
