Answer:
Option A, Hormones are controlled by a feedback loop; information about a system is sent back to the controller of the system to improve its function.
Explanation:
Negative feedback loop controls the hormone production and release. This is done by eliciting the release of substances till a certain level after which the stop signal is activated thereby preventing further release. By this method, concentration of hormones in blood is maintained within the narrow range.
For example – Thyroid hormones is released when the anterior pituitary signals the thyroid. This continues till the hormones in the blood reach the threshold level. Once the threshold level is reached, hypothalamus receives a feedback and then signals anterior pituitary to inhibit further signaling to the thyroid
Hence, option A is correct
Answer:
Ligand A and ligand B can cause same cellular responses in a cell when they are attached to different receptors.
Explanation:
If two same ligands are attached to two different receptors, two different responses will occurs. Such type of response is present in acetylcholine, while when two different ligands attached to two different receptors, same response will occur. This type of response is present in glucagon and epinephrine etc. ligands are responsible for controlling the transcription process when it binds or attached to the DNA molecule of the cell.
Answer:
They do not belong to the same population
Explanation:
These two similar birds do not belong to the same population because a population is made up of groups of similar organisms of the same species that occupy the same geographical region including the capability to interbreed. This two birds despite the similar markings, they do not have the capability to interbreed thus they are not of the same population.
<h2>
A change in one base of the gene sequence is known as point mutation.</h2>
Explanation:
Question 2 is incomplete.
3. A mutation that only affects a single nucleotide of nucleic acid is known as Point Mutation.
In Point mutations there is substitution of one base for another.
Example: TAT TGG CTA
TAC TGG CTA
The TAT changes to TAC which shows point mutation.
4. Yes. The point mutation have an effect on the outcome compared to the normal sequence.
When there is a change in one base of the gene it results into causing disease such as cancer, sickle cell anemia.
