Deck 9: Patterns of Inheritance

Question 1

The black arrow in the following image indicates one of the structures within a cell's nucleus that carries hereditary information.These structures contain segments that commonly encode the instructions for building proteins; one of these segments is called a(n)

A) genotype.
B) phenotype.
C) chromosome.
D) gene.

Answer 1

D

Question 2

An allele is

A) a version of a gene.
B) a trait that can be affected by the external environment.
C) always codominant to its counterpart in another chromosome.
D) the result of a change in phenotype.

Answer 2

A

Question 3

Each time a person has another child,the chance that the parent passes on a given allele to a child

A) is reduced.
B) is increased.
C) is the same.
D) changes.

Answer 3

C

Question 4

If a person has one copy of each of two different alleles for a given gene,the person is ________ for that trait.

A) heterozygous
B) homozygous
C) recessive
D) true-breeding

Question 5

A recessive allele can only appear in the phenotype of an individual

A) in the F1 generation.
B) exposed to certain environmental conditions.
C) who carries the mutation in his or her gametes.
D) who is homozygous for the mutation.

Question 6

Many genes contain instructions for building

A) carbohydrates.
B) steroids.
C) proteins.
D) lipids.

Question 7

The individuals Mendel observed in the F₁ generations were always

A) homozygous recessive.
B) homozygous dominant.
C) heterozygous.
D) codominant.

Question 8

Which of the following choices represents the genotype of an individual diploid organism?

A) BbCCdd
B) BCd
C) bCd
D) BbCd

Question 9

A mutation that occurs in a diploid cell can be inherited only if the

A) mutated allele is recessive.
B) mutated allele is dominant.
C) mutation occurs in a cell that produces gametes.
D) same mutation also occurs on the homologous chromosome.

Question 10

Which of the following statements is NOT true?

A) Two organisms with the same genotype are homozygous.
B) Two organisms with the same phenotype may have different genotypes.
C) A heterozygous organism may have the same phenotype as a homozygous organism.
D) A heterozygous organism has the same number of copies of a given gene as a homozygous organism.

Question 11

The following figure shows three generations in one of Mendel's experiments and demonstrates that purple flower color is dominant over white flower color in peas.Which of the following is the best rationale for this conclusion?

A) In the F2 generation, more plants have purple flowers. In any cross, the allele that is most common in the offspring is dominant.
B) Members of the F1 generation are heterozygous. Whatever allele is visible in a known heterozygote is considered dominant.
C) The stronger-or in this case, darker-allele is always considered dominant.
D) An individual allele that produces more offspring gives more alleles to the next generation. As a result, that allele dominates the next generation.

Question 12

The following figure shows three generations in one of Mendel's experiments.According to the data in this figure,Mendel's F₂ generation contains many more purple flowers than white flowers.Which of the following is the best explanation of this observation?

A) Three-quarters of the offspring must receive the white allele.
B) The chance of an individual offspring receiving a white allele is only 25 percent.
C) The probability of any individual offspring receiving at least one copy of the purple allele is 75 percent.
D) The white allele is only dominant in about 25 percent of the offspring that inherit it.

Question 13

Mendel's laws were able to accurately predict the pattern of inheritance for situations in which

A) alleles are affected by their environment.
B) one allele completely masks another allele.
C) alleles of one gene alter the effect of a different gene.
D) a given character is determined by more than one gene.

Question 14

Which of the following observations refutes the theory of blending inheritance?

A) When a red plant is crossed with a white plant, the resulting offspring are pink.
B) Most of the features of offspring are not intermediates of their parents' traits.
C) Gametes carrying different types of alleles cannot fuse successfully.
D) After meiosis, two copies of a given gene end up in the same gamete.

Question 15

A tall plant mates with itself and produces all tall offspring.This cross is repeated for many generations with the same results.The parental plant is most likely

A) heterozygous.
B) completely dominant.
C) mutated.
D) true-breeding.

Question 16

Which of the following pairs of words can be used correctly to describe alleles?

A) dominant or recessive
B) homozygous or heterozygous
C) genotype and phenotype
D) codependent and mutation

Question 17

Which of the following symbols correctly represents a person who has a homozygous genotype?

A) Ww
B) WW
C) XY
D) Wx

Question 18

Which of the following statements is true?

A) Specific mutations occur because they are needed.
B) Mutations only occur during development.
C) All mutations are harmful.
D) Gametes fuse without regard to which mutations they carry.

Question 19

Is it possible for two organisms with the same genotype to have different phenotypes?

A) No; identical genotypes lead to identical phenotypes.
B) No; the DNA of the recessive alleles not expressed in the phenotype is degraded within each cell.
C) Yes; the expression of the genotype can be affected by the environment.
D) Yes; the phenotype expressed determines what the genotype will be.

Question 20

A thoroughbred racehorse could have,at most,________ alleles of the same gene.

A) 16
B) 8
C) 4
D) 2

Question 21

In the cross depicted in the following illustration,two parent plants,one with red flowers and the other with white flowers,produce pink offspring.The white and red alleles for flower color in this plant exhibit

A) homozygosity.
B) codominance.
C) pleiotropy.
D) incomplete dominance.

Question 22

In the following Punnett square,the lettered circles on the top and left of the square (indicated by the arrows)represent the

A) offspring that will be produced by the cross.
B) genotypes of the parents involved in the cross.
C) gametes that may be produced by each parent involved in the cross.
D) offspring that could be produced by the cross.

Question 23

Which of the following represents all of the possible gametes that can be formed by an individual with the genetic makeup Ff GgHH ?

A) FGH, FgH, fGH, fgH
B) Ff, Gg, HH
C) FG, FH, Fg, fH, fG, fg, GH, gH
D) Ff GhHH, FFGGHH, f fgghh

Question 24

Which of the following statements is true?

A) Mendel's laws are less accurate than Punnett square results.
B) Mendel's laws are useful only in unusual situations.
C) Mendel's laws correctly explain how genes are inherited.
D) Mendel's laws correctly predict the phenotype of an organism.

Question 25

The best way to get accurate results from a probability exercise is to

A) choose an example with incomplete dominance.
B) know the answer in advance.
C) choose an example that will come out fifty-fifty.
D) make a large number of observations.

Question 26

Which of the following statements is a basic summary of one of Mendel's laws?

A) All beneficial human genetic traits are dominant, and harmful traits are recessive.
B) The pattern of inherited characteristics of organisms is not predictable.
C) The separation of alleles for one gene does not affect the separation of alleles for other genes.
D) Recessive alleles cause the death of the gamete.

Question 27

You are considering the inheritance of some human traits.One trait controls the quality of earwax,and it is controlled by the E gene.Wet earwax is dominant to dry earwax.Another trait is free or attached earlobes,represented by the A gene.Attached earlobes are recessive to free earlobes.Assume that a man who was pure-breeding for dry earwax and free earlobes had children with a woman who was pure-breeding for attached earlobes and wet earwax.What would be the genotype of their offspring?

A) EEAA
B) Eeaa
C) eeAa
D) EeAa

Question 28

If the D allele is completely dominant over the d allele,what percentage of the offspring will have the dominant phenotype when two heterozygous individuals mate?

A) 25 percent
B) 50 percent
C) 75 percent
D) 100 percent

Question 29

The following figure depicts red blood cells from a mother,a father,and their child.The mother and father are the biological parents of the child.What is the mother's genotype for ABO blood type?

A) IAIA
B) IAIB
C) IAi
D) ii

Question 30

A Punnett square is used to

A) determine the source of new alleles.
B) determine how many genes control a given trait.
C) predict the gametes that will be produced by an organism.
D) predict the outcome of a genetic cross.

Question 31

When two individuals who are heterozygous for a gene are mated,we would predict a dominant to recessive phenotypic ratio of ________ in the offspring.

A) 1:2:1
B) 1:3
C) 3:1
D) 9:3:3:1

Question 32

What is the smallest number of traits that are needed to test Mendel's law of independent assortment?

A) one
B) two
C) four
D) eight

Question 33

The leaf color of a certain plant is controlled by one gene.For that gene,the allele G = orange and g = green.You have a plant with orange leaves,but do not know whether that plant's genotype is GG or Gg.Which of the following would help you determine the plant's genotype?

A) Cross the plant to another plant with orange leaves.
B) Cross the plant to a plant with green leaves.
C) Cross two true-breeding, orange-leaved plants to each other and then cross one of their offspring to the plant with the unknown genotype.
D) Change the environment in which the plant grows to find the conditions that cause the leaves to produce the orange color.

Question 34

Cystic fibrosis is caused by a recessive gene.If C = normal and c = cystic fibrosis,how can a child with cystic fibrosis have two parents who do not have cystic fibrosis?

A) The child has a genotype of CC.
B) The parents have genotypes of CC and Cc.
C) The parents have genotypes of Cc and Cc.
D) The child has a genotype of Cc.

Question 35

An individual with the genotype Aa mates with an individual with the genotype AA.Which of the following is true?

A) These two individuals will have four offspring.
B) Half of the offspring will be Aa.
C) Twenty-five percent of the offspring will be aa.
D) Seventy-five percent of the offspring will be AA.

Question 36

Which of the following expresses Mendel's law of segregation?

A) All dominant alleles of different genes divide into different cells from the recessive alleles.
B) Two copies of a gene separate during meiosis and end up in different gametes.
C) When gametes form, the genes originally from one parent all end up in different gametes from the genes originally from the other parent.
D) Gametes with recessive alleles will only fuse with each other.

Question 37

Two pea plants are mated that are heterozygous for height where the tall (T )trait is dominant to short plants (t),and flower color where white flower color ( p)is recessive to purple flower color (P).What is the ratio that one would expect in their offspring?

A) 3:1
B) 1:1
C) 1:1:1:1
D) 9:3:3:1

Question 38

Two humans mate who are heterozygous for earlobe shape where attached earlobes (A)are dominant to free earlobes (a),and earwax quality where dry earwax (e)is recessive to wet earwax (E ).What is the probability that their first child will have dry earwax and attached earlobes?

A) 1/2
B) 3/16
C) 9/16
D) 1/16

Question 39

Suppose D were dominant and d were recessive,and you could label the D allele in the P generation with a radioactive substance that could be inherited over several generations.You create hybrids by mating your radioactive DD individuals to dd individuals.Finally,you cross two Dd individuals.In 1,000 offspring,how many do you predict would be radioactive?

A) 250
B) 500
C) 750
D) 1,000

Question 40

In a genetic cross of Gg with Gg guinea pigs,none of the four offspring were gg.This outcome

A) disproves Mendel's law of independent assortment.
B) neither supports nor disproves Mendel's law of independent assortment.
C) supports Mendel's law of independent assortment.
D) supports Mendel's law of segregation.

Question 41

Humans have many genes that contribute to the unique array of proteins found on their red blood cells.Your MN blood type (the letters indicate the presence of M and N proteins on the red blood cells)is determined by the codominant alleles Lᴹ and Lᴺ.Which of the following genotypes could NOT be produced when a man with MN blood and a woman with MN blood mate?

A) LMLM
B) LMLN
C) LNLN
D) LMNLM

Question 42

Alternate versions of the same gene,such as blue or brown for eye color,are known as ________.

Question 43

The expressed characteristics of an organism are known as its ________.

Question 44

Inheritance of ABO blood type in humans is an example of

A) incomplete dominance.
B) complete dominance of one allele over another.
C) a gene that is coded by only one allele.
D) epistasis.

Question 45

The first generation of phenotypes resulting from a genetic cross between two members of the parental generation would be seen in the ________ generation.

Question 46

A controlled mating experiment used to examine the inheritance of a particular gene is called a genetic ________.

Question 47

Two genes control fur color in Labrador retrievers.The first gene determines whether the pigment to be deposited in the hair will be black or brown.The second gene determines whether the pigments are put into the dog's hair at all.A dog homozygous for the recessive allele of this second gene will be yellow because no pigment is deposited in its fur.This is an example of

A) epistasis.
B) pleiotrophy.
C) codominance.
D) incomplete dominance.

Question 48

The genetic makeup of an organism,such as Gg,is its ________.

Question 49

Siamese cats have dark fur on their extremities (paws,nose,ears,and the tail),while the rest of their bodies are covered with lighter hair,despite the fact that only one gene controls their coat color.Why does the coat color differ at different places on a Siamese cat's body?

A) Melanin can be produced in the extremities because they are colder than the rest of the body.
B) Melanin can be produced in the extremities because they are warmer than the rest of the body.
C) Tyrosinase, which is needed for pigment formation, does not function in the colder extremities.
D) Tyrosinase, which is needed for pigment formation, does not function in the warmer extremities.

Question 50

An offspring of sexually reproducing parents carries a total of 32 alleles for 16 different genes.Thus,the offspring inherited ________ alleles from each parent.

Question 51

Feather color in a certain species of bird is controlled by a pair of alleles that exhibit incomplete dominance.If birds that are homozygous for one allele are black and birds that are homozygous for the other allele are white,then heterozygous birds would be

A) black.
B) white.
C) gray.
D) black with white stripes.

Question 52

Two parents have ABO blood group genotypes of Iᴬi and IᴬIᴮ.Which of the following blood types could NOT belong to one of their children?

A) AB
B) B
C) O
D) A

Question 53

We need a hammer to pound nails into a board.Even if we have the nails,we cannot pound them without first getting hold of a hammer.This is similar to the genetic relationship known as

A) heterozygosity.
B) codominance.
C) epistasis.
D) independent assortment.

Question 54

A pigment in mammals that is responsible for yellow to red hair color is

A) eumelanin.
B) pheomelanin.
C) tyrosine.
D) albinin.

Question 55

Polygenic inheritance combined with environmental influence typically produces a wide range of phenotypic classes that grade smoothly from one to the next.This type of pattern is known as

A) punctilious variation.
B) punctuationism.
C) continuous variation.
D) epistasis.

Question 56

Most human genetic traits are

A) controlled by one gene.
B) not inherited according to Mendel's laws.
C) controlled by more than one gene.
D) not heritable.

Question 57

One of the first medical tests a newborn receives determines if the child has phenylketonuria (PKU).PKU is the result of a mutation in a single gene that causes mental retardation and a host of other phenotypes (light hair and skin color,eczema,and a "mousy" smell).By detecting PKU early,doctors are able to reduce the effect of this condition with a modified diet.PKU is an example of

A) epistasis.
B) a polygenic trait.
C) pleiotropy.
D) codominance.

Question 58

If an offspring of two diploid parents carries a total of 32 different genes,it inherited ________ genes from each of those parents.

Question 59

The lettered fragment indicated by the black arrow in the following image is the part of a chromosome responsible for encoding and producing one of the molecules that ultimately determines one or more of the phenotypes of an individual.These phenotype-determining molecules are known as ________.

Question 60

Inheritance of ABO blood type in humans is an example of

A) pleiotropy.
B) epistasis.
C) incomplete dominance.
D) a gene that is coded by more than two alleles.

Question 61

New alleles arise as a result of independent assortment during meiosis.

Question 62

A genetic cross is used to produce organisms from species that would not normally interbreed.

Question 63

When gametes are formed,the separation of alleles for one gene is unrelated to the separation of alleles for other genes.This idea is known as Mendel's law of ________.

Question 64

If the influence of two alleles is fully displayed in the heterozygote without being diminished by the presence of the other allele or being suppressed by a dominant allele,the two alleles are said to be ________.

Question 65

Experiments involving small numbers of offspring give more reliable results than experiments observing large numbers of offspring.

Question 66

There are no known exceptions to Mendel's law of independent assortment.

Question 67

Mendel's hypotheses regarding inheritance in peas were generally accepted when he published them in 1865.

Question 68

Humans exhibit a variety of physical,biochemical,and behavioral characteristics that are based on their DNA sequences.

Question 69

If both copies of a given gene in an organism are identical,the organism is homozygous for that trait.

Question 70

When a ________ variety of a plant is self-fertilized,all of its offspring have the same phenotype as the parent.

Question 71

Chromosomes are located on genes.

Question 72

Before Gregor Mendel,it was believed that offspring should be intermediate in phenotype to their two parents and that it should be impossible for "lost" traits to reappear in later generations.This idea was known as ________ inheritance.

Question 73

During meiosis,two copies of a gene separate and end up in different ________.

Question 74

By observing the offspring in a series of pea-breeding experiments,Gregor Mendel deduced the laws of ________.

Question 75

The Iᴬ and Iᴮ alleles involved in human blood type differ in that they attach different ________ to the surface of red blood cells.

Question 76

The first reaction in the chain of enzyme-catalyzed chemical reactions that convert the amino acid tyrosine into eumelanin or pheomelanin is orchestrated by an enzyme encoded by the C gene.This enzyme is called ________.

Question 77

The first reaction in the chain of enzyme-catalyzed chemical reactions that convert the amino acid tyrosine into eumelanin or pheomelanin is orchestrated by an enzyme encoded by the C gene.Homozygotes for the recessive allele of this gene (cc)exhibit the ________ phenotype.

Question 78

In the following Punnett square,the genotypes inside the boxes (a few are indicated by arrows here)represent the number and type of offspring that a given pair of individuals will produce when mated.

Question 79

A genetic cross in which the heterozygous phenotype is intermediate between the two homozygous phenotypes is an example of ________.

Question 80

The plant shown in the following image would be considered a hybrid.