Explanation

The most likely genotypes of the parents of a baby girl with hemophilia are that the mother is a carrier and the father is a hemophiliac.. 

Hemophilia is X-linked recessive:

This means the gene for hemophilia is located on the X chromosome, and a female needs both copies of the recessive gene to express the disorder. 

Male genotype:

Males have only one X chromosome, so if they inherit the hemophilia gene, they will have the disease. 

Female genotype:

Females have two X chromosomes. If they inherit one copy of the hemophilia gene and one copy of the normal gene, they will be carriers but won't have the disease. 

Explanation

Ribosomal RNA (rRNA) makes up the largest proportion of total cellular RNA. 

rRNA is the primary component of ribosomes, which are essential for protein synthesis.

It constitutes roughly 80% of the total cellular RNA. 

Explanation

The organelle that has increased significantly in the muscle cells of an active athlete compared to a physically inactive individual of the same age is the Mitochondrion. 

Mitochondria are known as the "powerhouses" of the cell because they are responsible for producing the majority of the cell's energy in the form of ATP through aerobic respiration.