Chapter 10
monohybrid
A ----------------------cross is a mating between two individuals that are both heterozygous for the same, single gene.
c
A ______ organism always produces offspring that are identical to the parent when self-fertilized. a. heterozygous b. false-breeding c. true-breeding d. hybrid
haploid
A cell with one set of chromosomes is a(n) ______ cell.
b
A diploid cell contains Multiple choice question. a. one homolog for the autosomes and two homologs for the sex chromosomes. b. two full sets of chromosomes. c. only one copy of each type of chromosome. d. three full sets of chromosomes.
d
A gene that has two codominant alleles and one recessive allele, such as the gene conferring human blood type, has ______ possible genotypes and ______ possible phenotypes. Multiple choice question. a. 4; 6 b. 6; 3 c. 6; 4 d. 3; 6
a
A human ______ cell has 46 chromosomes, 23 chromosomes from each parent. a. diploid b. sperm c. haploid d. homologous
d
A pea plant with purple flowers of unknown genotype is test crossed with a white-flowered pea plant (ff), and half of the offspring have purple flowers and half the offspring have white flowers. What is the genotype of the purple flower? Multiple choice question. a. FF b. FF ff c. ff d. Ff
monohybrid
A------------------cross is a mating between two individuals that are both heterozygous for the same, single gene.
b
An example of a(n) ______ cross is the mating of two rats that both contain the alleles Ff for fur color. This cross is made to examine which of two fur colors their offspring will have. Multiple choice question. a. dihybrid b. monohybrid c. mutant d. test
dihybrid
An example of a(n) ______ cross is the mating of two rats that both have the genotype Ff Tt for fur color and tail length to examine which of two fur colors and tail lengths their offspring will have.
d
Blood clotting is an example of how Multiple choice question. a. two alleles can be incompletely dominant. b. nondisjunction can lead to different numbers of chromosomes. c. one gene affects multiple phenotypes. d. many genes and proteins affect the same phenotype.
b
Cystic fibrosis is an example of ______ because a defect in one gene causes several phenotypic effects. Multiple choice question. a. incomplete dominance b. pleiotropy c. epistasis d. a dominant disorder
e
For X-linked disorders caused by dominant alleles in humans, what individuals are likely to vary in severity of symptoms due to random X chromosome inactivation? a. Multiple choice question. b. heterozygous females c. homozygous dominant females d. males with one dominant allele e. males with one recessive allele
haploid
Gametes, or sex cells, are -----------------, meaning they contain only one set of chromosomes.
linked
Genes that are located on the same chromosome and inherited together are called ------- genes.
b
Homologous chromosomes are a. two nucleic acids joined at the centromere and created by the replication of one chromosome. b. chromosomes that look alike and have the same sequence of genes but may not carry the same alleles. c. chromosomes that look alike but have different genes in different positions. d. chromosomes that carry the same alleles but have a dissimilar structure and size.
d
Homologous chromosomes contain the same genes but may contain different alleles at a particular site, called a gene Multiple choice question. a. autosome. b. testcross. c. centrosome. d. locus.
b
If a gene exists in 10 different alleles in a population, how many alleles can be expressed in one diploid cell? Multiple choice question. a. ten b. two c. five d. eight
d
If both parents contribute identical versions of a gene, then the offspring are ______ for that gene. Multiple choice question. a. hybrid b. heterozygous c. homologous d. homozygous
d
If parents contribute different versions of a gene, then the offspring are ______ for that gene. Multiple choice question. a. true-breeding b. homozygous c. recessive d. heterozygous
recessive
If the genotype for a trait is Tt, the t allele is called the---------------allele, whose effect is masked by the other allele.
c
If the image shows the results of a testcross between a pea plant with green seeds (genotype yy) and a pea plant with yellow seeds of unknown genotype, then what is the genotype of the yellow-seeded plant? Multiple choice question. a. Yy b. yy c. YY
c
In Mendel's experiments, a true-breeding pea plant with yellow seeds (YY) was mated with a true-breeding pea plant with green seeds (yy). What was the genotypic ratio of the F1 generation? Multiple choice question. a. 25% YY, 50% Yy, 25% yy b. 100% YY, 0% Yy, 0% yy c. 0% YY, 100% Yy, 0% yy d. 50% YY, 25% Yy, 25% yy
a
In Mendel's experiments, the hybrid plants had what genotype? a. heterozygous b. homozygous recessive c. homozygous dominant
a
In Mendel's studies, a ______ trait is one that could mask the appearance of another trait. Multiple choice question. a. dominant b. true-breeding c. recessive
Pleiotropy
In ______, one gene encodes a protein that is important in many biochemical pathways or that affects many parts of the body.
test
In a ---------- cross, an individual with an unknown genotype is mated with an individual with a homozygous recessive genotype to determine the unknown genotype.
c
In a cross between two traits, Mendel mated a pea plant of true-breeding round, yellow seeds (RR YY) with a pea plant of true-breeding wrinkled green seeds (rr yy). What is the genotypic ratio of the F1 generation? Multiple choice question. a. 50% RR yy, 50% rr YY b. 100% RR YY c. 100% Rr Yy d. 50% RR YY, 50% rr yy
incomplete
In a gene expression pattern called -----------------dominance, the heterozygote has an intermediate phenotype between the homozygotes.
a
In a test cross, a homozygous recessive pea plant with green seeds is mated with a yellow-seeded plant of unknown genotype. If all the progeny have yellow seeds, then the genotype of the yellow-seeded plant is Multiple choice question. a. homozygous dominant. b. heterozygous. c. homozygous recessive.
d
Mendel conducted his experiments of inheritance using ______ because they are easy to grow and cross, show distinguishable traits, and produce many offspring. a. fruit flies b. wheat c. nematodes d. pea plants
independent assortment
Mendel deduced the law of ---------------------------which states that alleles for one gene are randomly separated into gametes in a way that is not influenced by the separation of alleles of another gene.
100
Mendel mated a pea plant of true-breeding round, yellow seeds (RR YY) with a pea plant of true-breeding wrinkled, green seeds (rr yy). A Punnett square analysis shows that -----------% of the F1 generation has round, yellow seeds.
c
Mendel's ______ states that alternative versions of genes are packaged into separate gametes. Multiple choice question. a. law of mitotic division b. law of independent assortment c. law of segregation d. law of meiotic division
c
Mendel's ______ states that the segregation of alleles for one gene does not influence the segregation of alleles for another gene during gamete formation. a. law of mitotic division b. law of meiotic division c. law of independent assortment d. law of segregation
b
One of the reasons that Mendel was able to discover the basic principles of genetics using pea plants is because pea plants a. develop slowly. b. self-fertilize and cross-fertilize. c. produce only a small amount of offspring each generation. d. exhibit traits in forms that are blended and that differ from either parental trait.
1 3 5
Select all of the following that are true about dominance and recessiveness. Multiple select question. 1. A dominant allele may encode enough normal protein to mask the presence of the recessive allele. 2. The effects of a recessive allele can only be seen when an individual inherits one dominant allele and one recessive allele. 3. A dominant allele may cause a disease, such that the dominant allele is very rare. 4. Recessive alleles are always rare because they are produced by rare mutations. 5. Recessive alleles typically encode nonfunctional proteins.
3 4
Select all of the following that are true about genotype or phenotype. Multiple select question. 1. A genotype for an individual usually varies among the individual's cells. 2. Genotype includes height, hair color, and foot shape. 3. Some phenotypes can be affected by the environment. 4. Phenotype may not be readily visible.
1 2 3
Select all of the following that are true about linked genes. 1. do not assort independently 2. located on the same chromosome 3. inherited together 4. produce a phenotypic ratio of 9:3:3:1 in the F2 offspring of a dihybrid cross 5. encoded the seven traits Mendel studied
1 3 4
Select all of the following that are true of Marfan syndrome. Multiple select question. 1. many symptoms, such as weak aorta, lens dislocation, long limbs 2. one gene's produce affects the expression of another gene, which encodes membrane proteins for the transport of water 3. pleiotropic gene expression 4. caused by a dominant allele 5. affected by mutations in several different genes
product
The ----------- rule states that the chance of two independent events occurring is equal to the product of the individual chances that each event will occur.
a
The I gene encodes enzymes that produce red blood cell surface molecules, but the production of the cell surface molecules requires a precursor molecule encoded by the H gene. In individuals with genotype hh for the H gene, the precursor molecule is not produced. In other words, expression of the I gene is affected by the H gene product. This is an example of Multiple choice question. a. epistasis. b. incomplete dominance. c. pleiotropy. d. codominance.
genotype
The ______ is the combination of alleles an individual has for a particular gene.
a
The exchange of genetic material between homologous chromosomes during prophase I of meiosis is called ______ and can explain the appearance of ______ in the offspring. Multiple choice question. a. crossing over; recombinant traits b. crossing over; parental combinations of traits c. exon splicing; recombinant traits d. exon splicing; parental combinations of traits
c
The law of independent assortment deduced by Mendel states that Multiple choice question. a. the four alleles for two genes assort randomly during meiosis, such that gametes may contain all four alleles or no alleles. b. the dominant alleles for one gene assort with the dominant alleles for a second gene, and the recessive alleles for both genes also assort together. c. the assortment of alleles for one gene does not influence how the alleles for a second gene assort during gamete formation. d. the alleles for one gene are packaged into one set of gametes, and the alleles for a second gene are packaged into a different set of gametes.
b
The law of segregation deduced by Mendel states that a. the alleles of two separate genes are linked, such that they segregate together into gametes. b. the two alleles of each gene segregate from each other during gamete formation. c. the two alleles of each gene are packaged into the same gamete, such that they do not separate. d. the alleles of two separate genes assort independently from each other during gamete formation.
c
The picture shows human ABO blood types. AB blood type is an example of Multiple choice question. a. pleiotropy. b. incomplete dominance. c. codominance. d. epistasis.
b
To determine if the genotype of a pea plant with a dominant phenotype is homozygous dominant or heterozygous, a ______ may be completed. Multiple choice question. a. homologous pairing b. test cross c. karyotype d. Gram stain
codominance
Two different alleles of a heterozygous genotype are both fully expressed to produce the phenotype in a type of expression called ----------------------
d
Using the knowledge of Mendel's law of segregation, construct a Punnett square for two heterozygous (Ff) parents who are healthy but are carriers of cystic fibrosis. What is the chance that a child of these parents will have cystic fibrosis (ff)? Multiple choice question. a. 0% b. 75% c. 50% d. 25%
d
What are the observable characteristics of an individual's genes? Multiple choice question. a. allelotype b. genotype c. chromotype d. phenotype
d
What describes an inheritance pattern that shows incomplete dominance? a. A phenotype is produced by the interaction of two or more genes. b. A single gene has multiple effects on phenotype. c. In heterozygotes, the two different alleles are fully expressed. d. Heterozygotes have a phenotype that is intermediate between those of the two homozygotes.
c
What is a consequence of multiple proteins being involved in one biochemical pathway? a. Inheritance patterns are simple because altered phenotypes usually result from mutation of the same gene. b. A mutation in one gene affects several different phenotypes. c. An altered phenotype can be due to mutations in different possible genes.
d
What type of gene expression was present in the seven traits Mendel studied? Multiple choice question. a. Linked genes affected phenotypic and genotypic ratios. b. Alleles were often codominant such that c. heterozygotes showed an intermediate phenotype. c. Temperature affected the phenotypic ratios. d. One allele was completely dominant over the other.
a
What type of plant undergoes self-fertilization to produce some offspring that are identical to the parent and some that are different? a. hybrid b. homozygous c. true-breeding d. recessive
a
What type of protein interaction involves the phenotype of one gene inhibiting or enhancing the expression of another gene? Multiple choice question. a. epistasis b. pleiotropy c. incomplete dominance d. codominance
c
When Mendel mated two F1 generation yellow-seeded (Yy) pea plants, what was the phenotypic ratio in the F2 offspring? (Green-seeded pea plants are genotype yy.) Multiple choice question. a. 2 yellow seeds: 1 green seed b. 3 yellow seeds: 1 green seed c. 3 green seeds: 1 yellow seed d. 1 yellow seed: 1 green seed
d
When Morgan crossed a male fruit fly that was heterozygous for two genes (AaBb) with a female fruit fly that was homozygous recessive for the same two genes (aabb), most of the offspring were either homozygous recessive or heterozygous for both genes, indicating that a. independent assortment had occurred. b. crossing over had occurred frequently. c. the genes for these traits are on different chromosomes. d. the genes for these traits are linked.
b
When one gene's products affect the expression of another gene, this is called Multiple choice question. a. pleiotropy. b. epistasis. c. environmental effects. d. continuous variation.
a
Which of the following is a dihybrid cross? Multiple choice question. a. RrYy x RrYy b. RR x yy c. Rr x Rr d. RRYY x rryy
b
Which of the following is a genotype? Multiple choice question. a. functional protein b. Aa c. yellow seeds d. blood type A
b
Which of the following is a phenotype? Multiple choice question. a. homozygous b. purple flowers c. Gg d. pp
a
Which of the following represents a monohybrid cross? Multiple choice question. a. Yy x Yy b. YY x yy c. RrYy x RrYy
a
X-linked recessive disorders can affect more human males than females because ______ always express the disorder when they inherit the recessive allele from ______. Multiple choice question. a. males; the mother b. females; the mother c. males; the father d. females; the father
a
rue or false: A dominant allele can be rare, and a recessive allele can be common. a. True b. False