Lethal alleles cause the death of an organism prenatal or after the birth. Lethal alleles are usually a consequence of a mutation and they can be recessive, dominant or conditional. Since the lethal dominant alleles are harmful whether they are carried in homozygous (e.g.AA) or heterozygous (e.g.Aa) form, a strong selection against them is present and thus these alleles are much more rare.
Parents: Homozygous brown-eyed (M) -
B B blued-eye (F) -
b b [since blue (b) is recessive then and brown (B) is dominant then
in order for the blue gene to
show the you need double recessive or the brown
gene absent
Offspring:
So based on the Punnett cross then you realize that all the possible of spring carry the
genotype B b and as such the
phenotype brown eyes
During T cell maturation, the t cells must pass two tests. first, immature t cells that can recognize MHC molecules are Selection. Second, immature t cells that recognize and bind to molecules normally found in the body are Activation.
Selection is the first test that T cells must pass. During this process, immature T cells that can recognize MHC molecules are selected. MHC molecules are found on the surface of cells and are involved in antigen presentation. When T cells come into contact with MHC molecules, they are able to recognize the molecules and begin the process of selection. During selection, the T cells that recognize MHC molecules are chosen over those that do not. This helps ensure that the cells that are selected are those that can properly respond to antigens.
The second test that T cells must pass is activation. During activation, T cells that recognize and bind to molecules normally found in the body are selected. These molecules are called self-antigens and can include proteins, carbohydrates, and lipids. When T cells come into contact with self-antigens, they are able to recognize the molecules and begin the process of activation. During activation, the T cells that recognize self-antigens are chosen over those that do not. This helps ensure that the cells that are selected are those that will not attack the body’s own cells.
Learn more about self-antigens at : brainly.com/question/24468411
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The answer is kelvin. That is a unit of temperature.
