<u>Answer</u>: option B they have a random gene mutation that affects their fur colour.
<u>Explanation</u> :-
- <em>Variation</em> is the phenomena which occurs in all populations.
- These variations result in slight differences in the phenotypes of individuals .
- These variations only arise due to <em>random mutations </em>that arise in the individuals’ genome and then can be inherited by their offspring.
- There is always a probability of one particular trait to make the individuals survive better in the environment as compared to other trait.
- The individuals having the trait that helps them to survive better in the environment tend to survive more and leave more progeny. This is termed as <em>survival of the fittest</em>.
- Thus, according to the question it can be inferred that the dark fur colour arose due to a <em>random mutation </em>since it is the only source of variation. Since, in the given environmental conditions the mice having the dark fur colour were less susceptible to the predators they are better fitted to survive.
- The dark brown fur coat mice, survive better, leave more progeny and hence, increase their population with time. However, the orginal source of origin of this trait was a random mutation. Had this mutation not occured, the dark coloured fur mice would not have been there.
So, a <em>random gene mutation affecting the fur colour made the dark coloured mice first appear in the population.</em>
Answer: G)Vacuole
Explanation:
G)Vacuole is the answer. Hope this helps!
Answer:
C
Explanation:
A prokaryote is a typically unicellular organism that lacks a nuclear membrane-enclosed nucleus.
The correct answer is: D) secretin
Gastric secretion is highly regulated whether its secretion should be increased (when food is eaten) or decresed (as the stomach empties). Secretion is controlled by the nervous system and endocrine system that work together. There are three phases of gastric secretory control:
Cephalic-by the brain
Gastric-by the stomach itself
Intestinal- by the small intestine
All of three can work simultaneously.
Secretin is released by duodenal enteroendocrine cells and it stimulates the pancreas and gall bladder, but also suppresss gastric secretion and motility. Secretion of the secretin is stimulated by the chime and it is the part of intestinal phase.
