Question 1

Scientists have long been interested in differences between dogs and wolves in their social behavior toward humans. Dogs and wolves share a common ancestor. In trying to understand the differences, a researcher analyzed data collected from 18 domesticated dogs and 10 wolves that had been raised by humans. Which data would be most useful to understand the genetic basis of this behavior?
A)The pedigree for the dogs and the geographic location from which the wolves came.
B)The number of chromosomes in wolves and dogs.
C)Differences in DNA sequences between the dogs and the wolves.
D)Examination of DNA from the ancient ancestor of dogs and wolves.

Accepted Answer

Differences in DNA sequences between the dogs and the wolves would provide insights into the genetic variations that may account for differences in social behavior toward humans.

Question 2

Please refer to the following art to answer the following questions. 
-In the accompanying art, you see a table with the actual number of offspring that resulted from a dihybrid cross. The numbers do not show the 9:3:3:1 ratio predicted. One phenotype occurred more than predicted; another occurred less. The reason could be because ________.
A)of errors in mitosis
B)some of the alleles were linked
C)of polygenic inheritance

Accepted Answer

Some of the alleles were linked.

Question 3

The parents of a child with unusual disease symptoms take the child to a doctor for help. The doctor suspects that the condition might have a genetic basis. She recommends that the child be taken to a specialty clinic where physicians and staff members are trained to diagnose genetic diseases and counsel parents. Ultimately, the child is diagnosed with a rare recessively inherited disease. The parents are tested for the gene, and both are found to be heterozygous. The parents are expecting another child and ask about a test to determine if this child may carry the disease. All but one of these tests may detect genetic disorders in the unborn child. Choose the EXCEPTION.
A)chorionic villus sampling
B)pedigree analysis
C)blood tests to measure levels of alpha-fetoprotein
D)amniocentesis

Accepted Answer

Pedigree analysis is a method of studying the inheritance of traits within a family. It cannot be used to detect genetic disorders in the unborn child.

Question 4

Widow's peak, a pointed hairline on the forehead, is a genetic trait caused by a dominant allele. It can be traced back through a family's history using pedigree analysis.
The pedigree shown here is of three generations of a family. Notice that some individuals (shown in gray)have a widow's peak (W = dominant allele and w = recessive allele). 
-Mary has the genotype ________.
A)WW
B)ww
C)Ww

Accepted Answer

The genotype "Ww" indicates that Mary has one dominant allele (W) and one recessive allele (w), which is a common way to represent heterozygosity in genetics.

Question 5

Scientists have long been interested in differences between dogs and wolves in their social behavior toward humans. Dogs and wolves share a common ancestor. In trying to understand the differences, a researcher analyzed data collected from 18 domesticated dogs and 10 wolves that had been raised by humans. If she discovered that the degree of social relationship a dog exhibited toward humans was positively correlated with a chemical modification of a part of a chromosome rather than what alleles a dog had, this would be an example of ________.
A)pleiotropy
B)incomplete dominance
C)epigenetics
D)polygenic inheritance

Accepted Answer

Epigenetics involves changes in gene expression or phenotype caused by mechanisms other than changes in the underlying DNA sequence, such as chemical modifications of chromosomes.

Question 6

Scientists have long been interested in differences between dogs and wolves in their social behavior toward humans. Dogs and wolves share a common ancestor. In trying to understand the differences, a researcher analyzed data collected from 18 domesticated dogs and 10 wolves that had been raised by humans. Which data would be most useful to this study?
A)The degree of DNA similarities between dogs and humans.
B)The extent to which the dogs and the wolves sought assistance from humans when presented with a challenge.
C)The extent to which the dogs and the wolves licked and vocalized to their pups.
D)A measurement of the number of times the dogs and the wolves communicated with one another when threatened.

Accepted Answer

This data would directly address the research question by comparing how domesticated dogs and wolves interact with humans, particularly in seeking assistance, which is a key aspect of social behavior.

Question 7

Widow's peak, a pointed hairline on the forehead, is a genetic trait caused by a dominant allele. It can be traced back through a family's history using pedigree analysis.
The pedigree shown here is of three generations of a family. Notice that some individuals (shown in gray)have a widow's peak (W = dominant allele and w = recessive allele). 
-Janice's genotype is ________.
A)Ww
B)WW
C)ww
D)WW or Ww

Accepted Answer

The genotype "WW or Ww" indicates that Janice could be either homozygous dominant or heterozygous for a trait, depending on the context provided.

Question 8

To determine the phenotype of an individual who expresses a dominant trait, you would cross that individual with an individual who is homozygous recessive for that trait. This technique is referred to as a(n)________.
A)dihybrid cross
B)test cross
C)amniocentesis
D)pedigree analysis

Accepted Answer

A test cross is a cross between an individual with a dominant phenotype and an individual who is homozygous recessive for the trait in question. This technique is used to determine the genotype of the individual with the dominant phenotype.

Question 9

This hypothetical pedigree for a disease in humans illustrates inheritance that is ________. 
A)autosomal recessive
B)autosomal dominant
C)sex-linked dominant
D)carried on the Y chromosome

Accepted Answer

The answer of This hypothetical pedigree for a disease in...

Question 10

A mating between a purebred purple-flowered pea plant and a purebred white-flowered pea plant would be called a ________.
A)pedigree analysis
B)monohybrid cross
C)test cross
D)dihybrid cross

Accepted Answer

A monohybrid cross is a mating between two individuals that are homozygous for different alleles of a single gene. In this case, the purple-flowered pea plant is homozygous for the dominant allele for purple flowers, and the white-flowered pea plant is homozygous for the recessive allele for white flowers. The offspring of this cross will all be heterozygous for the flower color gene, and will all have purple flowers.

Question 11

Please read the following scenario to answer the following question.
The parents of a child with unusual disease symptoms take the child to a doctor for help. The doctor suspects that the condition might have a genetic basis. She recommends that the child be taken to a specialty clinic where physicians and staff members are trained to diagnose genetic diseases and counsel parents. Ultimately, the child is diagnosed with a rare recessively inherited disease. The parents are tested for the gene, and both are found to be heterozygous. The parents want to have another child but are afraid this child will also be affected.
-What would genetic counselors say is the probability that the second child will have the disease?
A)1/2
B)1/4
C)1/8
D)1/16

Accepted Answer

The parents are both heterozygous, which means they each have one copy of the normal gene and one copy of the mutated gene. When they have a child, each parent has a 50% chance of passing on the normal gene and a 50% chance of passing on the mutated gene. If both parents pass on the mutated gene, the child will have the disease. If one parent passes on the normal gene and the other parent passes on the mutated gene, the child will be a carrier, but will not have the disease. If both parents pass on the normal gene, the child will not have the disease or be a carrier. Therefore, the probability that the second child will have the disease is 1/4.

Question 12

Humans have been applying the principles of genetics for many years without actually knowing about genes. Evidence for this is that humans ________.
A)have rerouted waterways in order to trade with people in distant regions
B)clear forests to plant crops
C)choose to save seeds from plants with the best yield to plant for the next generation
D)and other species are subject to many of the same diseases

Accepted Answer

Humans have practiced selective breeding by choosing seeds from plants with desirable traits, such as high yield, to plant in subsequent generations, which is an application of genetic principles.

Question 13

-Recombinant offspring were produced by the mating shown in the accompanying art. What is the recombination frequency of purple-round and red-long offspring?
A)21%
B)381
C)21 + 21
D)11%

Accepted Answer

The answer of 
-Recombinant offspring were produced by the mating...

Question 14

Experience with dog breeding has taught geneticists that ________.
A)given enough time, any desired trait can be bred into dogs
B)purebred dogs are often sterile due to inbreeding
C)while physical traits can be molded through artificial selection, behavioral traits cannot
D)geographically isolated groups of dogs may be selected for quite different traits, resulting in a different dog breed

Accepted Answer

Geographically isolated groups of dogs can be selectively bred for different traits, leading to the development of distinct dog breeds.

Question 15

Widow's peak, a pointed hairline on the forehead, is a genetic trait caused by a dominant allele. It can be traced back through a family's history using pedigree analysis.
The pedigree shown here is of three generations of a family. Notice that some individuals (shown in gray)have a widow's peak (W = dominant allele and w = recessive allele). 
-This pedigree supports the fact that widow's peak is due to a dominant allele, because if it were due to a recessive allele and both parents show the recessive phenotype, then ________.
A)half of the sons would have a widow's peak
B)all of the offspring would have a widow's peak
C)none of the daughters would have a widow's peak
D)all of the daughters and none of the sons would have a widow's peak

Accepted Answer

The answer of Widow's peak, a pointed hairline on the...

Quiz 9: Patterns of Inheritance

To determine the phenotype of an individual who expresses a dominant trait, you would cross that individual with an individual who is homozygous recessive for that trait. This technique is referred to as a(n) ________.

This hypothetical pedigree for a disease in humans illustrates inheritance that is ________.

A mating between a purebred purple-flowered pea plant and a purebred white-flowered pea plant would be called a ________.

Humans have been applying the principles of genetics for many years without actually knowing about genes. Evidence for this is that humans ________.

-Recombinant offspring were produced by the mating shown in the accompanying art. What is the recombination frequency of purple-round and red-long offspring?

Experience with dog breeding has taught geneticists that ________.