Answer:
Explanation:
The phospholipid bilayer is also known as the cell membrane. It covers cells and regulates the transport of substances. Certain ones can pass and others cannot, depending on certain factors like size and polarity.
Smaller substances tend to diffuse or move across the membrane quite easily. However, larger molecules have a much harder time. Many depend on special proteins embedded in the membrane. These are called transport proteins and they form a channel so large molecules can still move in or out of the cell.
So, salt, water, and fats do not contribute to the movement of larger molecules, but <u>channel or transport proteins do and choice A is correct. </u>
<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:
raising awareness programmes,keeping environment clean,being attentive in social activities ,etc.
Answer:
Secretion of the neurotransmitter serotonin, which is a water-soluble amine molecule
Explanation:
Exocytosis is defined as the process where cell transports secretary products which are packaged in transport vesicles such as antibodies, peptide hormones, secretory proteins, and enzymes with the help of cytoplasm to the plasma membrane.
Some example of exocytosis are:
1) Neurotransmitters secrets from nerve cells.
2) Antigens which helps to stimulate the immune response.
3) Proteins of the plasma membrane.
