Deck 10: Foundations of Genetics

Question 1

Foxes,cats,and rabbits have enzymes that are heat-sensitive,causing a seasonal variation in coat color due to:

A) an environmental effect
B) multiple alleles
C) pleiotropy
D) incomplete dominance

Answer 1

A

Question 2

The degree of earlobe attachment in humans is inherited as a simple dominant of free earlobes,or as a recessive allele of attached earlobes.What is the probability that a woman with attached earlobes will have children with attached earlobes if their father has free earlobes,but his father had attached earlobes?

A) 1 in 2
B) 3 in 4
C) 1 in 10
D) None

Answer 2

A

Question 3

Gregor Mendel's work was different from that of other researchers working on inheritance in his day because he alone:

A) was a religious man
B) worked with pea plants
C) knew how to grow plants
D) actually counted the numbers and types of offspring

Answer 3

D

Question 4

What discovery by T.H.Morgan finally determined that genes were carried on chromosomes?

A) Heat-sensitivity of certain enzymes determining coat color
B) Sex-linked inheritance of eye color in fruit flies
C) The finding of complete dominance
D) Discovery of the Rh blood group

Question 5

Down syndrome in humans is due to:

A) monosomy (one copy of chromosome #21)
B) two Y chromosomes
C) trisomy (three copies of chromosome #21)
D) three X chromosomes

Question 6

Mendel tested for heterozygotes by using:

A) dihybrid cross
B) testcross
C) monohybrid cross
D) true-breeding cross

Question 7

What is the probability of getting a pea plant with recessive green seed color when two heterozygous pea plants,both having the dominant yellow-seeded phenotype,are crossed with each other?

A) 1 in 6
B) 1 in 4
C) 1 in 2
D) None

Question 8

If several traits are affected by the same allele,the allele is said to be:

A) recessive
B) dominant
C) epistatic
D) pleiotropic

Question 9

Which procedure is the least-invasive method of assessing fetal health while development is still occurring?

A) Amniocentesis
B) Chorionic villus sampling
C) Ultrasound
D) Karyotyping

Question 10

Humans who have lost one copy of a chromosome are called ____________ and generally do not survive development.

A) monosomics
B) trisomics
C) eusomics
D) diploids

Question 11

Genes for sex-linked traits tend to be carried on what chromosomes?

A) Chromosome 21
B) Any of the autosomes
C) Y chromosomes
D) X chromosomes
E) Chromosome 13

Question 12

When two true-breeding parental genotypes are crossed,the offspring are referred to as the:

A) true recessives
B) test cross
C) F₁ generation
D) F₂ generation

Question 13

Red-green colorblindness is a sex-linked trait.A woman with normal color vision,whose father was colorblind,mates with a colorblind man.What chance do each of their sons have of being colorblind?

A) 50% chance
B) 100% chance
C) 0% chance
D) 10% chance

Question 14

In snapdragons,pink-flowered plants are produced when red-flowered plants are crossed with white-flowered plants.This type of inheritance can best be described as:

A) simple dominant and recessive traits
B) codominance
C) incomplete dominance
D) sex-linked traits

Question 15

Two true-breeding pea plants are crossed,one with purple flowers and the other with white.Their offspring are:

A) heterozygous with the dominant phenotype
B) homozygous with the recessive phenotype
C) a mixture of purple and white flowers with varying genotypes
D) still true-breeding,with the same parental genotypes

Question 16

The diploid number of chromosomes in pea plants is 14.What is the haploid chromosome number?

A) 56
B) 28
C) 14
D) 7

Question 17

Tall is dominant to dwarf in pea plants.If two dwarf pea plants were crossed,their offspring will be:

A) all tall plants
B) all dwarf plants
C) half tall,half dwarf plants
D) plants of an intermediate height

Question 18

Human height shows a continuous variation from the very short to the very tall.Height is most likely controlled by:

A) epistatic genes
B) sex-linked genes
C) mutations
D) multiple genes

Question 19

Hemophilia is a group of different inherited blood-clotting disorders.Which is true about hemophilia?

A) It causes sterility.
B) It is more common in females than in males.
C) It is more common in males than in females.
D) It is inherited only on the autosomes.

Question 20

In the human ABO blood grouping,there are four basic blood types,type A,type B,type AB,and type O.The blood proteins A and B are:

A) simple dominant and recessive traits
B) codominant
C) incompletely dominant
D) sex-linked traits

Question 21

The ability to taste PTC is a dominant trait.If a heterozygote woman has a child with a man who is not a taster,what is the chance their child will be a taster?

A) 100%
B) 75%
C) 50%
D) 25%
E) 0%

Question 22

There are 3 alleles that lead to the ABO blood types.How many alleles does an individual inherit from their parents?

A) 1
B) 2
C) 3
D) 4
E) None of the choices is correct.

Question 23

Which of the following is a sex-linked disorder?

A) Cystic fibrosis
B) Hemophilia
C) Huntington's disease
D) Tay-Sachs disease
E) Hypercholesterolemia

Question 24

Whose work with fruit flies presented the first clear evidence that the genes determining Mendelian traits reside on chromosomes?

A) Karl Correns
B) Gregor Mendel
C) Thomas Hunt Morgan
D) Walter Sutton

Question 25

Which of the following crosses represents a dihybrid cross?

A) RRrr x DdDd
B) RR x Dd
C) RrDd x RrDd
D) RD x Rd
E) Rd x RR

Question 26

The gene for ABO blood type encodes an enzyme that adds sugar molecules to lipids on the surface of red blood cells.

Question 27

Mendel's "factors" for inheritance are now known to be ________.

Question 28

Put the following terms in the correct order from start to finish.

A) gene → chromosome → messenger RNA → primary transcript → protein → polypeptide
B) chromosome → gene → primary transcript → messenger RNA → protein → polypeptide
C) primary transcript → chromosome → gene → protein → polypeptide → messenger RNA
D) chromosome → gene → primary transcript → messenger RNA → polypeptide → protein
E) gene → messenger RNA → primary transcript → chromosome → protein → polypeptide

Question 29

A ______________ is a long molecule that contains genes and has proteins to help it retain its shape.

Question 30

Mendel's law that states only one allele specifying an alternative trait can be carried in a particular gamete is called the _________________________________.

Question 31

White flower color is recessive to purple.What is the genotypic ratio when two heterozygous pea plants are crossed?

A) 3:1
B) 4:0
C) 1:2:1
D) 1:1
E) 2:1

Question 32

A dominant human genetic disorder that does not reveal itself until middle age is _______________.

Question 33

An individual is said to be _____________ if it has two copies of the same factor for a given trait.

Question 34

All of the following are recessive traits in humans except:

A) mid-digital hair
B) albinism
C) common baldness
D) red-green color blindness
E) sickle-cell disease

Question 35

What is the product of transcription?

A) DNA
B) Genes
C) Protein
D) RNA
E) All of the choices are correct.

Question 36

Where does transcription take place in the cell?

A) The nucleus
B) The endoplasmic reticulum
C) The Golgi complex
D) The cytoplasm
E) On the ribosomes

Question 37

Which of the following represents a test cross?

A) Tt x tt
B) TT x Tt
C) Tt x Tt
D) tt x tt
E) TT x TT

Question 38

A central role for chromosomes in heredity was first suggested by:

A) Karl Correns
B) Gregor Mendel
C) Thomas Hunt Morgan
D) Walter Sutton

Question 39

Nondisjunction of chromosomes resulting in aneuploidy occurs during:

A) anaphase of mitosis
B) prophase I
C) metaphase II
D) anaphase I or II
E) telophase I

Question 40

The outward expression of an organism's genotype is referred to as its genotype.

Question 41

When a gene is carried on one of the sex chromosomes,it is said to be __________________.

Question 42

Mendel's Law of Independent Assortment states that genes located on different chromosomes are inherited independently of one another.If this is the case,what happens when two genes are located on the same chromosome,are they inherited together,do they separate,or both?

Question 43

______________ is the interaction between the products of two genes in which one of the genes modifies the phenotypic expression produced by the other.

Question 44

Why is coat color in Labrador retrievers an example of epistasis?

Question 45

A woman with blood type B has a baby with blood type O.A man she says is the baby's father has blood type A,but he denies having fathered the child.Could he be the father?

Question 46

A genetic family tree can more correctly be called a ____________.

Question 47

What is the possible advantage of being heterozygous for the sickle-cell gene?

Question 48

What is the evolutionary significance of mutation?

Question 49

If a white-flowered pea plant (ww)is crossed with a heterozygous purple-flowered plant (Ww),what will their offspring look like?

Question 50

When homologous chromosomes or chromatids fail to separate properly in meiosis,this is called _________________.