Chapter 9 - Patterns of Inheritance

Question 1

In humans, the ______ determines the sex of the offspring because ______

Answer 1

male…the male can contribute either an X or Y chromosome

Question 2

Mendel crossed purebred purple flowered plants with purebred white flowered plants, and all the resulting offspring produced purple flowers. The offspring are all _____ and the allele for purple flowers is _____

Answer 2

heterozygotes…dominant

Question 3

To determine the genotype of an individual who expresses a dominant trait, you would cross that individual with an individual who ______.

Answer 3

is homozygous recessive for that trait

Question 4

What name is given to the specific location of a gene on a chromosome?

Answer 4

Locus

Question 5

Attached earlobes are recessive to free earlobes. What is the probability of having a child with attached earlobes when an individual with attached earlobes mates with an individual heterozygous for free earlobes?

Answer 5

50%

Question 6

This genetic disorder causes red blood cells to assume an unusual shape and produce abnormal hemoglobin proteins.

Answer 6

Sickle-cell disease

Question 7

The best definition of a purebred plant is one that ______

Answer 7

self-fertilizes to produce offspring identical to the parent.

Question 8

The sex chromosomes in humans that make an individual a male are ____

Answer 8

X and Y

Question 9

You cross a true-breeding red-flowered snapdragon with a true-breeding white-flowered snapdragon. All of the F1 are pink. What can you say about the alleles for the parental traits?

Answer 9

Red and white show incomplete dominance

Question 10

The physical traits of an organism are called its

Answer 10

phenotype

Question 11

What is the key to the recognition of incomplete dominance?

Answer 11

The phenotype of the heterozygote falls between the phenotypes of the homozygotes.

Question 12

A mating between a purebred purple-flowered pea plant and a purebred white-flowered pea plant would produce a(n) _______

Answer 12

hybrid

Question 13

The scientific study of heredity is called _____

Answer 13

genetics

Question 14

An individual who is heterozygous _____

Answer 14

carries two different alleles for a gene

Question 15

A purebred plant that produces yellow seeds is crossed with a purebred plant that produces green seeds. The F1 plants have yellow seeds. What is the expected phenotypic ratio of seed color of the offspring of an F1 x F1 cross?

Answer 15

3:1

Question 16

What is the key to the recognition of co-dominance?

Answer 16

The heterozygote expresses the phenotype of both homozygotes

Question 17

The genetic make up of an organism that determines its physical trait is called its _____

Answer 17

genotype

Question 18

Which of the following techniques is used to collect fetal cells during pregnancy for genetic testing?

Answer 18

amniocentesis

Question 19

According to Mendel’s law of segregation ______

Answer 19

allele pairs separate in gamete formation

Question 20

Which of the following is used to define a phenotypic characteristic resulting from the expression of two or more genes?

Answer 20

Polygenic inheritance

Question 21

In a dihybrid cross ration, what is the probability of getting the genotype aa when you cross genotypes Aa and aa?

Answer 21

1/2

Question 22

In humans, the presence or absence of dimples is a trait that is controlled by a single gene. What is the genotype of an individual who is heterozygous for dimples?

Answer 22

Dd

Question 23

In humans, the inheritance of _____ is best explained as being polygenic.

Answer 23

height

Question 24

Alleles are described as _____

Answer 24

alternate versions of a gene

Question 25

A gene that is located on a sex chromosome (X or Y chromosome) is ______

Answer 25

a sex-linked gene

Question 26

Mendel’s law of independent assortment states ______

Answer 26

each pair of alleles segregates independently of the other pairs of alleles during gamete formation

Question 27

What is it called when one gene influences several characteristics?

Answer 27

Pleiotropy

Question 28

Red-green colorblindness is an example of ______

Answer 28

sex-linked disorder