Mendel's Laws Homework Assignment

Having identical alleles for a gene

. homozygous

List Mendel's five hypotheses that he derived from his monohybrid cross experiments

1. There are alternate forms of genes called alleles. 2. For each character, an organism gets two alleles, one from each parent. 3. If the two alleles differ, then the allele that has an effect is known as the dominant, and the allele that has no effect is known as the recessive. 4. Allele pairs separate from one another during gamete formation. 5. During meiosis, the distribution of alleles to gametes is random.

Assume that green eyes in humans are dominant to blue eyes. Further assume that these are the only two colors and that human eye color follows Mendel's rules. A true-breeding green-eyed male produces offspring with a true-breeding blue-eyed female. What color eyes will the offspring have?

All of the children would have green eyes.

The following cross, TtVv × TtVv, is an example of which of the following?

Dihybrid cross

A man with a recessive disease (the recessive phenotype) mates with a woman who is not affected with the disorder. However, two of their five children have the disorder. What do we now know about the woman's genotype? Assume the disorder follows the rules of Mendel.

She is a carrier (heterozygous).

Assume that a student is in the F1 generation. The children of that student would be in what generation?

The F2 generation

Mendel's law of independent assortment states that allele pairs segregate independently of one another during gamete formation. What accounts for this behavior of alleles during gamete formation?

This is due to the behavior of chromosomes during gamete formation (meiosis I)

True or false: Mendel always got close to a 9:3:3:1 ratio for phenotypes in the F2 generation of any dihybrid cross.

True

Are the two A alleles in Figure 11-6a on page 177 of your textbook the same gene?

Yes, they are the same gene and the same allele of that gene.

An alternate form of a gene

allele

why you have two of every gene?

because genes are carried on chromosomes, and you receive two of every chromosome because each parent gives you one of each chromosome.

When an allele determines the appearance of an organism

dominant

Having two different alleles for a gene

heterozygous

The mating of two organisms that differ in one trait

monohybrid cross

When an allele has no noticeable effect on an organism

recessive

Purple flowers are dominant to white flowers in pea plants. A gardener mates a purple plant with a white plant and records the offspring as having all purple flowers. The gardener just performed a(n) ____________ and determined that the purple plant's genotype was ____________________.

testcross; homozygous dominant