Chapter 3

Question 1

Approximately once in every _____ births, a newborn survives with 45, 47, or even 48 or 49 chromosomes instead of the usual 46.

a. 166
b. 2166
c. 16
d. 20,166

Answer 1

a. 166

Question 2

RNA affects genes and alleles by:

a. inserting additional DNA
b. turning some on and some off
c. encouraging activation of desirable traits
d. removing inactive ones

Answer 2

b. turning some on and some off

Question 3

ames was born with the genes to be a professional athlete, but his environmental experiences never supported the development of his potential athletic ability. So he never became a professional athlete. This example illustrates the concept of a trait being _____.

a. monozygotic
b. multifactorial
c. nonadditive
d. polygenic

Answer 3

b. multifactorial

Question 4

A fatal central nervous system disorder caused by a copy number variation in which more than 35 repetitions of a particular set of three base pairs are present is _____.

a. Down Syndrome
b. fragile X syndrome
c. Huntington’s disease
d. nearsightedness

Answer 4

c. Huntington’s Disease

Question 5

After about the eight-cell stage within the zygote, cells start to _____, meaning that they take different forms and reproduce at various rates depending on where they are located.

a. duplicate
b. divide
c. differentiate
d. detach

Answer 5

c. differentiate

Question 6

Genes with various repeats or deletions of base pairs are referred to as _____.

a. polygenic
b. copy number variations
c. autosomes
d. polymorphic

Answer 6

b. copy number variations

Question 7

Allen learned in his college biology class that, in sex chromosomes, the _____.

a. Y chromosome is larger than the X chromosome and has more genes
b. X and Y chromosomes are the same size, but the X chromosome has more genes
c. X and Y chromosomes are the same size and have the same number of genes
d. X chromosome is larger than the Y chromosome and has more genes

Answer 7

d. X chromosome is larger than the Y chromosome and has more genes

Question 8

The first 22 chromosomes contain hundreds of genes in the same positions and sequence. If the code of the gene from one parent differs from the code on the same gene from the other parent, the gene pair is _____.

a. monozygotic
b. dizygotic
c. heterozygous
d. homozygous

Answer 8

c. heterozygous

Question 9

A couple has been trying to conceive a child for 12 months. They decide to consult with a doctor, who makes the general recommendation that they consider using _____ to try to conceive a child.

a. multifactorial
b. assisted reproductive tech
c. in vitro fertilization
d. intra-cytoplasmic sperm injection

Answer 9

c. in vitro fertilization

Question 10

Alice loves to share information that she has learned from school with her parents. She came home one day and, at dinner, told her family that she learned about cell differentiation in science class. The information that she tells them is correct, so over dinner she told them that once cells differentiate _____.

a. they can no longer transform into different cells
b. the can still tranform into different cells
c. only cells in the brain can still transform into different cells
d. the can transform in stem cells

Answer 10

a. they can no longer transform into different cells

Question 11

When the effects of genes add up to make the phenotype, they are called _____ genes.

a. nonadditive
b. dominant
c. recessive
d. additive

Answer 11

d. additive

Question 12

Each gene directs the formation of specific protiens mad from a string of:

a. DNA
b. chromosomes
c. amino acids
d. gametes

Answer 12

c. amino acids

Question 13

Individuals have 23 ____ in every cell of the body:

a. pairs of genes
b. pairs of chromosomes
c. genes
d. chromosomes

Answer 13

b. pairs of chromosomes

Question 14

Jackie rushed into the house after school and announced to her parents, “My personality is _____! So many genes make me who I am!”

a. nonadditive
b. monozygotic
c. polygenic
d. multifactorial

Answer 14

c. polygenic

Question 15

One of the surprising findings from the Human Genome Project was that _____.

a. humans are extremely genetically different from each other.
b. humans have far fewer genes than had previously been thought
c. It is easy to predict exactly how genes from one parent will interact with the genes from the other
d. humans have far more genes that had previously been thought.

Answer 15

b. humans have fare fewer genes than had previously been thought.

Question 16

A small section of a chromosome that is the basic unit for the transmission of heredity is a:

a. gamete
b. genotype
c. gene
d. zygote

Answer 16

c. gene

Question 17

Scott and Darpa are siblings who have the same parents. Scott has heavy, straight eyebrows, whereas Darpa has thinner, arched eyebrows. These differences in eyebrow shape are due to different _____ that each sibling received from their parents.

a. gender
b. alleles
c. advice
d. nurture

Answer 17

b. alleles

Question 18

A common reason that couples do not seek genetic counseling is that _____.

a. their pregnancy is unplanned
b. they have never been exposed to teratogens
c. they already eat a well-balanced diet
d. they are well over the age of 35

Answer 18

a. their pregnancy is unplanned

Question 19

A variation that makes a gene different in some way from other genes for the same characteristics is a(n) _____.

a. genotype
b. chromosome
c. zygote
d. allele

Answer 19

d. allele

Question 20

Males have one X and one Y on _____.

a. each sperm
b. each stem cell
c. the 23rd pair of chromosomes
d. the 43rd chromosome

Answer 20

c. the 23rd pair of chromosomes

Question 21

Research indicates that alcohol use disorder is caused by _____

a. poor moral character
b. a combination of nature and nurture
c. nature only
d. nurture only

Answer 21

b. a combination of nature and nuture

Question 22

The most common extra-chromosome condition is _____:

a. Turner syndrome
b. fragile X syndrome
c. nearsightedness
d. Down syndrome

Answer 22

d. Down syndrome

Question 23

Lacy has a recessive gene in her genotype that is not expressed in her phenotype. She is a(n) _______ of that gene.

a. recipient
b. expresser
c. reactor
d. carrier

Answer 23

d. carrier

Question 24

The general term for the techniques designed to help infertile couples conceive and then sustain a pregnancy is _____.

a. intra-cytoplasmic sperm injection (ICSI)
b. multifactorial
c. in vitro fertilization (IVF)
d. assisted reproductive technology (ART)

Answer 24

d. assisted reproductive technology (ART)

Question 25

Identical twins are also called _____ twins.

a. gamete
b. zygotic
c. monozygotic
d. dizygotic

Answer 25

c. monozygotic

Question 26

Which characteristic has been found to affect nearsightedness?

a. too much vitamin A in the diet
b. age
c. too much time spent outdoors
d. gender

Answer 26

b. age