<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:
Carrector pill muscles hair follicles
Explanation:
melanocytes and keratin are present in the epidermis
The limbic cortex. Another area called the precuneus also plays a role.
The cell membrane is composed of a phospholipid bilayer.
The cell membrane is primarily composed of a mix of proteins and phospholipids
Phospholipids are a major component of cell membranes. They a head and a tail. The head is hydrophilic (attracted to water) and the tail is hydrophobic (repelled by water).
They form a bilayer in which their hydrophilic heads face the aqueous cytosol and extracellular fluid while their hydrophobic tails face away from the cytosol and extracellular fluid.
The lipid bilayer is semi - permeable
A scientific model is a claim or a theory that helps explain how a phenomenon works or how it undergoes process. This models provides scientists an understanding of the object or a situation undergoes change and generate certain outcomes or effects.