Biology 103 - Module 6 Study Guide

FISH distinguishes chromosomes by using more than one fluorescent-tagged RNA strand, which will bind to complementary DNA sequences on a specific chromosome.

False

Geneticists study pedigrees in order to predict how traits determined by phenotype are inherited from one generation to the next.

False

Genotype can always be inferred from phenotype.

False

Males with Klinefelter syndrome lack a Barr Body.

False

Mendel's principle of independent assortment describes the separation of paired factors during the formation of gametes.

False

Sickle cell anemia and cystic fibrosis are examples of a homozygote advantage.

False

The Human Genome Project was completed in 2012 and revealed a genomic map of 38 million SNPs.

False

The debate over nature versus nurture in determining certain human characteristics can be explained by pleiotropic genes.

False

The presence of two X chromosomes supports the existence of a genetic locus.

False

The product rule is used to determine the probability that two parents with a Bb genotype will have a child who also has the Bb genotype.

False

The differences in traits observed in parents versus offspring

Genetic Variation

The study of heredity

Genetics

In Mendel's Experiment Results for Seven Characters, what was the dominant trait for pod color of the peas?

Green

The inheritance of traits from one generation to the next

Heredity

Tay-Sachs disease is a(n) ____ disease that results in blindness, intellectual disability, and death due to ____.

autosomal recessive; accumulation of lipids in brain cells

A couple in which the woman is homozygous dominant for clotting ability and the man has hemophilia A will produce:

carrier daughters and normal sons

Breeding a yellow dog with a brown dog produced puppies with both yellow and brown hairs intermixed. This is an example of

codominance

The position of a specific gene on a chromosome can be determined by:

fluorescent in situ hybridization

Scientists use the term ____________ to refer to the genetic makeup for that organism.

genotype

The genetic composition of an organism

genotype

Refer to the accompanying figure. Based on the phenotypes of the third generation, the genotype of the father in the second generation must be:

heterozygous for albinism

The genotypes of the normal females in the second generation in accompanying figure are:

heterozygous for albinism

Individuals who are ____ for sickle cell hemoglobin tend to be ____ resistant to falciparum malaria but do not experience the effects of sickled red blood cells.

heterozygous; more

The chromosome theory of inheritance, developed by Sutton and Boveri, provided an explanation for Mendel's principle of segregation by proposing that

homologous chromosomes segregate during meiosis.

A Barr body in a mammalian female cell represents a(n)

inactivated X chromosome.

A cross of two medium height hybrid plants produces offspring that are dwarf, medium, and tall in a ratio of 1:2:1. This is an example of

incomplete dominance.

Translocation occurs when:

part of a chromosome breaks off and attaches to a nonhomologous chromosome

Mating a pure-bred pink rose plant with a pure-bred pink rose plant will produce

plants with only pink roses.

A gene that controls seed coat color in peas also determines the susceptibility of these peas to a particular disease. This situation is referred to as

pleiotropy

Huntington's disease is caused by a:

nucleotide triplet repeat

Preimplantation genetic diagnosis is done:

on cells of an in vitro fertilized embryo

Dominant traits remove recessive traits when both are present in the same individual.

False

The height of pea plants from a cross between parent plants heterozygous for height, in which tall is dominant, would be

3 tall: 1 short.

Two Martians fall in love and marry. One Martian is homozygous for red eyes and the other is heterozygous. The recessive eye color is purple. What is the probability that they will have a child with purple eyes (assuming Martians have similar genetics to humans)?

0

What are the predicted phenotypes of the male children from the union of a woman who is heterozygous for hemophilia and a man who has normal blood clotting characteristics? (Use the Punnett square to verify your answer.)

1 hemophilia:1 healthy

What is the probability that two lizards heterozygous for stripes on their tails (Ss) will produce homozygous offspring with no stripes (ss)?

1/4

An individual who inherits the specific chromosome ____ deletion from his/her ____ will most likely have Prader-Willi syndrome rather than Angelman syndrome.

15; father

What are the predicted phenotypes of the children from a union of a woman who is heterozygous for hemophilia and a man who is normal? (Use the Punnett square to verify your answer.)

25 % hemophilia: 75% normal

The human genome contains about ____ genes, which comprises about _____ of the genome.

25,000; 2%

A couple who does not have cystic fibrosis but are both heterozygous has already had three girls with cystic fibrosis, and are hoping to have a healthy child for their fourth. What are the chances that the fourth child will be a healthy male?

3/8

In a two-point test cross, 36 of the offspring were recombinant types. The remaining 64 offspring were parental types. How many map units separate the two loci?

36

A lizard with a striped tail and a normal head is crossed with one having a normal tail and a spotted head. All the F1 progeny are normal (no stripes or spots). What progeny are expected from a cross of the F1 progeny? Assume that the genes conferring stripes and spots were on different chromosomes.

9 normal : 3 striped : 3 spotted : 1 striped and spotted

An organism with the genotype of AaXx can produce gametes containing ____ if the two genes are unlinked.

AX, Ax, aX, or ax

The color of certain genetically identical hydrangea flowers ranges from blue to purple to pink, depending on the level of aluminum in the soil. In which of the following types of soil is aluminum less soluble, and the flowers pink?

Alkaline soils

Alternative gene variants

Allele

Which of the following represents the possible genotype(s) resulting from a cross between one homozygous (BB) individual and one heterozygous (Bb) individual?

BB and Bb

Which of the following represents the possible genotype(s) resulting from a cross between a heterozygous individual (Bb) and one that is homozygous (bb)?

Bb and bb

Which statement accurately characterizes an ethical consideration surrounding human genetics?

Consanguineous matings are prohibited by half of U.S. states due to the increased risk of autosomal recessive alleles.

A mating between individuals with different alleles at two loci is known as?

Dihybrid cross

Which of the following statements about dosage compensation is false?

Dosage compensation is a mechanism that makes equivalent the two doses in the male and the single dose in the female.

Which of the following does NOT describe Mendel's research and proposed Model of Inheritance?

Factors may be expressed, hidden in a given generation or lost.

A test cross is performed to determine phenotype.

False

Which of the following refers to the expression of an intermediate phenotype in heterozygous individuals?

Incomplete dominance

What is the current status of gene therapy?

It is being evaluated to assess the risks associated with potential side effects.

Why has the dominant mutant allele for Huntington's disease been able to persist in human populations despite its devastating effects?

Its symptoms do not typically show until after the individual has had children.

___________ were originally designated the location of a particular gene on the chromosome.

Loci

Which of the following are inborn errors of metabolism?

PKU and alkaptonuria

The expression of a trait in an organism

Phenotype

____ refers to multiple independent pairs of genes having similar and additive effects on the same characteristic.

Polygenic inheritance

A heterozygous fruit fly with normal wings and a gray body (VvBb) is crossed with homozygous flies with vestigial wings and black bodies (vvbb). Out of 800 total F1progeny, 296 are normal gray, 328 are vestigial black, 99 are normal black, and 77 are vestigial gray. What is the best explanation for this result?

The loci for wing length and body color are on the same chromosome.

Blood types A, B, AB, and O are controlled by how many alleles representing a single locus?

Three

A male is neither homozygous nor heterozygous for his X-linked alleles; instead, he is always hemizygous.

True

If a cell has two X chromosomes, XIST will become active in one of them, producing a special type of regulatory RNA molecule known as long noncoding RNA..

True

Polyploidy may arise from the failure of chromosomes to separate during cell division or by the fertilization of an egg by more than one sperm.

True

The science of comparative genomics to study human gene function is possible because much of the human genome is conserved among other closely related species.

True

The theory of blending inheritance was shown to be false by Mendel's observations of dominant and recessive alleles.

True

Persons having an XO karyotype are sterile females. They have ____ syndrome.

Turner

The cells of female mammals, including humans, contain two __________.

X chromosomes

A karyotype reveals that an individual is XYY. Based on your knowledge of human genetics, you correctly conclude that this individual has ____, and is a phenotypically _____.

XXY karyotype; fertile male

Aneuploidies describe:

a condition in which an extra chromosome is present or one is absent

Alternative forms of a gene are called ___________.

alleles

Nondisjunction during mitosis leads to:

an individual with a clone of abnormal cells

Colchicine is a drug that:

arrests cells in mitotic metaphase

The offspring of two heterozygous gray-bodied, normal-winged flies should be 50% gray-bodied/normal wings (BbRr) and 50% black-bodied/vestigial wings (bbrr) because these alleles are linked. Suppose a small number, say 15%, of the offspring are instead black-bodied with normal wings. This is most likely the result of

crossing-over.

Gene targeting has been used in mice to produce strains that were either homozygous or heterozygous for ____.

cystic fibrosis

Cri du chat syndrome arises from:

deletion of part of chromosome 5

A heterozygous fruit fly with normal wings and a gray body (VvBb) is crossed with homozygous flies with vestigial wings and black bodies (vvbb). This type of cross is known as a

dihybrid cross.

Genetic screening can be used to identify:

diseases caused by single gene mutations

A gene that affects, prevents, or masks the expression of a gene at another locus is a(n) ____ gene.

epistatic

A fragile site:

is associated with cancerous cells

Autosomal monosomy is not seen in live births because:

its effects are so lethal as to cause spontaneous abortion early in pregnancy.

The physical location of a gene on a chromosome is called

its locus.

Nearly half of the pregnancies that end in miscarriage have:

major chromosomal abnormalities

Polyploidy:

may be the result of more than one sperm fertilizing an egg

In rabbits, coat color is governed by four alleles: C for dark gray, Cch for chinchilla, Ch for Himalayan, and c for white. This is an example of

multiple alleles.

The sperm in the figure below were most likely produced by:

nondisjunction

The range of phenotypic possibilities that can develop from a certain dog genotype under different environmental conditions is called the

norm of reaction.

The sex of a human is determined by the

presence of a Y chromosome.

Polyploidy is the:

presence of multiple sets of chromosomes

Fragile X syndrome:

results in learning, attention, and hyperactivity disabilities in males

The sex of most mammals, birds, and insects is determined by

sex chromosomes.

Mating an individual expressing a dominant phenotype, but whose genotype is unknown, with an individual expressing the corresponding recessive phenotype is an example of a(n)

test cross

All calico cats are female because

the calico phenotype is caused by random X chromosome inactivation.

The probability that two genes will be separated by crossing-over is related to

the distance between the two genes on the chromosome.

In genomic imprinting:

the expression of a gene in the progeny depends upon which parent the gene is inherited from.

The selective advantage linked to the high frequency of the cystic fibrosis allele in Caucasians is:

the prevention of excessive water loss associated with certain types of diarrhea

What was revealed with the completion of the Human Genome Project?

the sequence of the entire human genome

In rabbits, coat color is governed by four alleles: C for dark gray, Cch for chinchilla, Ch for Himalayan, and c for white. Each individual rabbit inherits a combined total of _____ coat color allele(s) from its parents.

two

In genetics, map units express the distance between

two loci on a chromosome.

A ____ is best used to demonstrate the linkage of two genes.

two-point test cross