Answer:
d. secondary endosymbiosis.
Explanation:
- When a living cell acquires another organism that eventually becomes a part of this cell, this process is known as primary endosymbiosis.
- When an organism that has already undergone primary endosymbiosis engulfs another eukaryotic organism then this process is known as secondary endosymbiosis.
- Secondary endosymbiosis has been known to occur in plastids because of which they are surrounded by two membranes. This bilayer is present because one of the layers is the original outer membrane of the organism and the other membrane is that of the organism that has been engulfed.
The data suggests that there is no change in height of sheep because of
Hardy Weinberg equillibrium.
Explanation:
Data given:
heights of 200 sheeps remains the same for two years.
reason=?
There is no change in the phenotype of the sheep population during two years as there is no effect of environmental factors, no evolution or genetic drift in the population. Such population happens due to Hardy Weinberg equillibrium.
This principle says that there will be no genetic variation in a population when no evolution causing factors are there. These factors are environmental, mutation, genetic drift, natural selection or gene flow. When no new alleles are added in the population it remains same.
Thus in case of the 200 sheeps it is assumed that they were in Hardy Weinberg equillibrium.
Answer:
An Oc mutation on the bacterial chromosome can affect the expression of structural genes on a F plasmid.
Explanation:
An Oc mutation is a mutation in which operator of an operon is constitutively active i.e. repressor fails to bind the operator which leads to unregulated gene expression.
An Oc mutation do not affect the expression of structural genes on F plasmid because <u>an operator is a cis regulatory element and therefore it can only affect the genes which are located on the same DNA</u>. F plasmid genes are located on the plasmid not on the main chromosome of the prokaryotes while tryptophan or lac operon system is in the main chromosome that is why an Oc mutation will not impact genes on plasmid.
