Patterns of Inheritance- Week 9

Question 1

During his experiments with pea plants, Mendel referred to the trait that was expressed in the F1 or first filial generation as _________________.

independent.
homozygous.

dominant.
heterozygous.

Answer 1

dominant.

Question 2

A diploid organism that has two identical alleles for a given trait is called _________for that trait.

dominant
codominant
heterozygous

homozygous

Answer 2

homozygous

Question 3

If an individual allele has more than one effect on the phenotype, this is called _____________________.

pleiotropy.
epistasis.
blending inheritance.
multiple alleles.

Answer 3

pleiotropy

Question 4

The independent assortment of allele pairs is due to __________________________.

the independent segregation of homologous chromosome pairs during anaphase I.
the independent segregation of non-sister chromatid pairs during anaphase II.
the independent segregation of homologous chromosome pairs during anaphase II.
the independent segregation of sister chromatid pairs during anaphase I.

Answer 4

the independent segregation of homologous chromosome pairs during anaphase I.

Question 5

An extensive study was conducted on identical twins who were separated at birth. Among other things, the study showed that the individual from each pair who received better nutrition during childhood tended to score higher on standardized intelligence tests. This can best be described as an example of how _____________________.

mutation alters phenotype.
environment alters genotype.

environment alters phenotype.
mutation alters genotype.

Answer 5

environment alters phenotype.

Question 6

Alternate forms of the same gene are called _______________.

genotypes.
cofactors.
homologues.

alleles.

Answer 6

alleles

Question 7

In modern terminology, Mendel’s heredity “factors” are called ______________.

chromosomes.
DNA.
RNA.
genes.

Answer 7

genes

Question 8

If a single gene has 3 or more alternative forms, this is called _________________.

blending inheritance.
epistasis.

multiple alleles.
pleiotropy.

Answer 8

multiple alleles.

Question 9

In Mendel’s experiments on seed color in pea plants, when a dominant yellow seed-bearing plant was crossed with a recessive green seed-bearing plant, what was the approximate phenotypic ratio among the F2 generation?

9:3:3:1
1 yellow: 3 green
3 yellow: 1 green
1 yellow: 1 green

Answer 9

3 yellow: 1 green

Question 10

Let P = purple flowers and p = white, and T = tall plants and t = short. What are the genotypes of the gametes that are produced by a plant that is heterozygous for both traits?

P, p, T, and t
PT and pt
PT, Pt, pT, and pt
PpTt only

Answer 10

PT, Pt, pT, and pt