PLEASE HELP !! This pedigree shows the inheritance of Tay-Sachs in a family. Tay-Sachs is a recessive
disorder that causes cells to be
unable to break down waste
products. These wastes build up in brain cells and cause damage and eventual death. Fill out the genotypes of each of the family members.

TT = normal
Tt = carrier
tt = disease

How many chromosomes does each human cell contain? a. 23 chromosomes b. 26 chromosomes c. 43 chromosomes d. 46 chromosomes

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

Achemical that is released by an animal as a signal to other members of the same species is called a pheromone. t or f