Answer:
An immune response is a reaction which occurs within an organism for the purpose of defending against foreign invaders. The first contact that an organism has with a particular antigen will result in the production of effector T and B cells which are activated cells that defend against the pathogen.
Explanation:
D) when cells are express different genes
Answer:
a: metaphase
Explanation:
the chromosomes are aligned at the metaphase plate
Answer:
genomic imprinting
Explanation:
Genomic imprinting is a mechanism for regulating gene expression that allows expression of only one of the parental alleles, although both alleles are functional. Unlike most genes in which expression is biallelic, genes that are subjected to this mechanism (imprinted genes) have monoalelic expression; By definition, in an imprinted loci, only one allele is active (maternal or paternal), and the inactive is epigenetically marked by histonic modification and / or methylation of cytosines.
Genomic imprinting can cause some disturbances, among them Prader-Willi syndrome, which is a genetic disorder that involves a partial deletion of chromosome 15q on the paternal chromosome.
Answer:
Natural selection
Explanation:
Sexual selection refers to the natural selection where the allele frequencies of a population are changed due to nonrandom mating between the individuals. Certain preferences for the mate by organisms result in sexual selection. It is mostly exhibited by females.
For example, peahen prefers the peacocks with elaborate tail features as their mate. The sexual selection also occurs when there is competition among the members of the same sex for a mate. This type of sexual selection is mostly exhibited by males and results in fighting and display.
