Answer:
The correct answer is D. proliferation and differentiation.
Explanation:
Primary immune response occurs due to the first exposure of an antigen to the immune system. The primary immune response is generally delayed by many days because it takes time for B and T cells to become cloned and to proliferate and differentiate.
Then after several days of proliferation and differentiation of activated T and B cells, T cells become effector T cells and B cell becomes plasma cells which then eliminates the antigen. Memory B and T cells are also produced during this process which helps in generating a quick immune response during the second and subsequent exposure of that antigen.
So the correct answer is D. proliferation and differentiation.
Answer:
Genotype: Bb (heterozygous)
Phenotype: brown fur
Explanation:
Since allele B is dominant to allele b, as long as genotype has allele B in it, its effect of phenotype will be expressed instead, regardless of whether allele b is present.
As mouse genotype is stated as Bb, on the chromosome from its parents, allele B comes from one parent while allele b is inherited from the other parent.
Phenotype is the expressed trait. In this case, as genotype has allele B, the phenotype will be brown fur as its effect is expressed.
The main reason for the species extinction is for the ecological changes.
Answer: A. The fossils cam from the same organism
Hope this helps!
Explanation: