<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>
Like what our backyards look like
if so then my backyard has tons of flowers and a big white shed
The statement is true that T-cells are a type of immune cell system that recognizes pathogens in the body.
T-cells are the lymphocytes that are involved in providing acquired immunity to the body. They can recognize the pathogens presented by the antigen presenting cells. There are two types of t cells: helper T cells and Cytotoxic T cells.
Immune cells are the cells of the immune system that are involved in protecting the body from infection, allergies and foreign pathogens. There are several immune cells that perform several functions. The example of such cells are: phagocytes, lymphocytes, dendritic cells, etc.
To know more about T cells, here
brainly.com/question/12324561
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A Punnet Square is what you're looking for :)
