What kind of Single Nucleotide Polymorphism is represented in the following diagram?

Which of the following scenarios describes an example of epistasis?

Red-green colour blindness is a sex-linked recessive trait in humans. Two people with normal colour vision have a colour-blind son. What are the genotypes of the parents?

In humans, ABO blood types refer to glycoproteins in the membranes of red blood cells. There are three alleles for this autosomal gene: IA, IB, and i. The IA allele codes for the A glycoprotein, The IB allele codes for the B glycoprotein, and the i allele doesn't code for any membrane glycoprotein. IA and IB are codominant, and i is recessive to both IA and IB. People with type A blood have the genotypes IAIA or IAi, people with type B blood are IBIB or IBi, people with type AB blood are IAIB, and people with type O blood are ii. If a woman with type AB blood marries a man with type O blood, which of the following blood types could their children possibly have?

Why are males more often affected by sex-linked traits than females?

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. At the same time, a second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all. The relationship between genes S and N is an example of which of the following inheritance patterns?

X-chromosome linked disorders affect:

The following question refers to the pedigree chart in the figure for a family, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle.

What is the likelihood that the offspring of IV-3 and IV-4 will have the trait?

Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following?

The following image is of a diatom viewed under a light microscope. The line A—B spanned 64 EPU. The same distance on the student’s drawing of the diatom measured 80 mm. What is  the length (in mm) of the scale bar required to represent 40 μm on the student’s drawing?