Genetics: The Science of Heredity

The scientific study of heredity is called genetics.

• True

• False

An organism's physical appearance is its genotype.

• True

• False

In codominance, neither of the alleles is dominant or recessive.

• True

• False

Which of the following is the first step in the formation of sex cells in an organism that has 8 chromosomes?

• The 2 chromatids of each chromosome separate.

• Chromosome pairs line up next to each other in the center of the cell.

• The DNA in the 8 chromosomes is copied.

• The chromatids move apart, producing cells with 4 chromosomes each.

The different forms of a gene are called

• Alleles

• Chromosomes

• Phenotypes

• Genotypes

The likelihood that a particular event will occur is called

• Chance

• Punnett Square

• Probability

• Recessive

An organism with 2 identical alleles for a trait is

• heterozygous

• homozygous

• dominant

• recessive

If the body cells of an organism have 10 chromosomes, then the sex cells produced during meiosis would have ____ chromosomes.

• 5

• 10

• 15

• 20

Create a Punnett square and determine the probability for the following. Mom has Brown hair BB and Dad had Blonde hair bb. What is the probability that their baby has blonde hair?

• 25%

• 50%

• 0%

• 100%

Create a Punnett square and determine the probability for the following. Mom and Dad are both heterozygous for freckles. The dominant gene is F and the recessive gene is f. What is the probability of their baby not having freckles.

• 0%

• 25%

• 50%

• 100%