Answer:
Im pretty sure it is the 1st option
Explanation:
I took Human geo. but I never got to finish it because I went online :/ But I hope I got it right for you
1. Memory cells that trigger a secondary immune response
2. Specific antibodies that remain concentrated in the bloodstream for life after the first infection event
3. Memory cells that trigger a primary immune response
4. T cells that trigger a primary immune response
Answer:
1. Memory cells that trigger a secondary immune response
Explanation:
During the first infection when the body is invaded by a particular antigen, the immune system tries to identify the type of antigen. B lymphocytes make antibodies when the antigen has been identified in the event of a primary infection. The response of the immune system during the primary infection of that pathogen is usually slow. As soon as the primary infection is arrested by the antibodies produced in response, memory cells such as the memory B cells is formed, which enables the immune system to identify the same pathogen, and thereby triggers a faster secondary immune response in subsequent infections by the same pathogen.
Answer:
The offsprings of this punnet square will be Dd, Dd, dd and dd in a ratio 1Dd : 1dd
See attached image for punnet square completion
Explanation:
This question involves a cross involving a single gene with alleles D and d where allele D is dominant over allele d i.e. D will mask the phenotypic expression of d in a heterozygous state.
This cross is between a heterozygous parent (Dd) and a homozygous recessive parent (dd). Parent Dd will produce gametes D and d while parent dd will produce gametes d and d.
Using these gametes in a punnet square, four possible offsprings with two distinct genotypes will be produced. The genotypes are: Dd and dd in a ratio 1:1
Hence, the possibility of having a heterozygous dominant offspring is 1/2 while the possibility of having a homozygous recessive offspring is also 1/2.
