Answer:
All of those answer are correct.
A) <u>Mutation</u> is the original source of variations for plants and other organisms which develops differences among their respective species
Explanation:
Genetic variation leads to the natural differences between each individual and among individuals of a species. The main cause for this variation is due to alleles that cause variations in the composition of genes or the DNA sequences.
A mutation is a genetic variation which leads to the creation of a new allele in a species population. Each variation in the DNA sequence leads to an allele formation and each allele leads to a difference in character or trait between individuals since they are the alternate version of the original genes.
Although genetic variations could be brought about by crossing over, random fertilization, or independent assortment; mutation is the original source because it provides the basic raw material for all the evolutionary changes.
Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines to assist the immune response.
Answer:
The probability of the parents having yellow-bellied off-spring is 100% because all the genotypes have a dominant Y.
It is possible for two yellow-bellied numbats to have a green bellied child if they are both hybrid Yy. The probability of the parents to have a green-bellied child is 25%
Answer:
Explanation:
Plants infected with white rot may have a cottony white or grey mass of fungal ... The disease can occur on all the vegetable alliums but tends to be more serious on garlic ... The fungus is an important pathogen on a number of non-allium crops ... a brown discoloration and rot, so that the shoot easily detaches from the base.