Deck 11: Simple Inheritance and Meiosis

Question 1

In diploid organisms,having two homologues of each chromosome can be beneficial if one allele of a gene encodes a nonfunctional protein.Can haploid organisms avoid the negative effects of nonfunctional alleles?

A) No,because there is only one allele for the gene in each cell,and the nonfunctional allele has no other allele to mask it.
B) No,because there are two chromosomes each with a single allele that is always the same,and one cannot compensate for the other being nonfunctional.
C) Yes,because there is only one allele for the gene in each cell,and the nonfunctional allele will be masked by another allele of a different kind.
D) Yes,because there are two chromosomes each with a single allele that is always the same,and one can compensate for the other being nonfunctional.
E) Yes,because there are always other alleles for other genes that will compensate for a nonfunctional allele.

Answer 1

A

Question 2

One of the purposes of meiosis is to _____.

A) produce four zygotes instead of only two (as produced in mitosis)
B) reduce the chromosome number in each resulting cell by half
C) increase genetic diversity in the diploid-starting cells
D) increase the number of embryos per fertilization
E) double the number of chromosomes per gamete

Answer 2

B

Question 3

Why is it possible for two healthy parents to give birth to a child with a genetic defect such as cystic fibrosis?

A) CF is normally caused by a mutation that occurs only in the sperm and eggs of the parents,so their bodies are not affected.
B) CF is normally caused by a mutation that occurs in the fetus during pregnancy,and it does not affect the mother.
C) CF is only evident in individuals with two mutant alleles;a healthy parent could carry both a defective allele and a normal allele.
D) CF is not passed to children from their parents;it comes from their grandparents.
E) CF is caused by the inheritance of too many "normal" genes;the parents would be unaffected.

Answer 3

C

Question 4

A human female has _____ chromosomes in each skin cell and _____ chromosomes in each egg.

A) 46;46
B) 23;46
C) 46;23
D) 23;23
E) 92;46

Question 5

A woman is heterozygous for the CF-associated gene (the alleles are represented here by the letters A and a.Assuming that meiosis occurs normally,which answer choice represents eggs that she can produce?

A) A
B) a
C) Aa
D) A or a
E) AA

Question 6

How do the two alleles of the CFTR gene in a lung cell differ?

A) They are inherited from different parents.
B) One is on chromosome 7 and one is on chromosome 3.
C) Only one is expressed.
D) They are inherited from different parents,they are on different chromosomes,and only one is expressed.
E) There is no difference because they are both the same gene.

Question 7

An alien has 82 total chromosomes in each of its body cells.The chromosomes are paired,making 41 pairs.If the alien's gametes undergo meiosis,what are the number and arrangement (paired or not)of chromosomes in one of its gametes?

A) 41 paired chromosomes
B) 41 unpaired chromosomes
C) 82 unpaired chromosomes
D) 82 paired chromosomes
E) 164 paired chromosomes

Question 8

Which phrase accurately describes meiosis?

A) contains two rounds of division (meiosis I and meiosis II)
B) ends with four gametes that are not the same genetically
C) takes one diploid cell to make four haploid cells
D) all of these
E) none of these

Question 9

Children often have many of the phenotypes of their parents because _____.

A) they have the exact same genotypes as their parents
B) they inherit half of their genetic material from each parent
C) they carry the same combinations of alleles that their parents have
D) they inherit mutations that make their bodies appear identical to one or both parents
E) the cells of embryos divide by meiosis,a process that yields genetic duplicates

Question 10

Besides recombination,what other event in meiosis increases the genetic diversity of the gametes?

A) the way in which chromosomes are replicated in meiosis II
B) the random line-up and separation of maternal and paternal chromosomes
C) the random exchange of DNA segments between paternal chromosomes
D) the random exchange of DNA segments between maternal chromosomes
E) the random way in which gametes fuse together to make uniquely different sperm and eggs

Question 11

Meiosis differs from mitosis in the _____.

A) way in which sister chromatids separate
B) number of cells produced immediately after the starting cells divide
C) number of chromosomes in the starting cells
D) number of sister chromatids in the starting cells
E) number of chromosomes in each ending cell

Question 12

A diploid cell of baker's yeast has 32 chromosomes.How many chromosomes are in each of its haploid spores?

A) 32
B) 16
C) 8
D) 64
E) 1

Question 13

In order for a child to develop cystic fibrosis _____.

A) a sperm carrying a CF allele must fertilize an egg that also has that allele
B) genetic recombination must occur in the father but not the mother
C) genetic recombination must occur in the mother but not the father
D) more than one sperm in the father must carry the CF allele
E) more than one egg in the mother must carry the CF allele

Question 14

Women can inherit alleles of a gene called BRCA1 that puts them at higher risk for breast cancer.The alleles associated with elevated cancer risk are dominant.Of the genotypes listed below,which carries the lowest genetic risk of developing breast cancer?

A) BB
B) Bb
C) bb
D) Bb and bb
E) All of these genotypes carry equal risk.

Question 15

If meiosis were to fail and a cell skipped meiosis I,so that meiosis II was the only meiotic division,how would you describe the resulting cells?

A) haploid cells with 23 pairs of chromosomes
B) diploid cells with 23 pairs of chromosomes
C) haploid cells with 23 unpaired chromosomes
D) diploid cells with 23 unpaired chromosomes
E) none of the above

Question 16

Which statement is true of a single human liver cell?

A) There are 46 chromosomes present.
B) There are two alleles for each gene.
C) There is one allele on each chromosome.
D) The number of chromosomes in this liver cell is referred to as diploid.
E) all of these

Question 17

Assume that Emily (who has CF,a recessive disease (aa))decides to have children with a man who does not have CF and who has no family history of CF.What combination of gametes can each of them produce,and what is the probability that they will have a child who is a carrier for CF?

A) Emily: aa,man: Aa;100% probability
B) Emily: Aa,man: AA;50% probability
C) Emily: aa,man: AA;100% probability
D) Emily: aa,man: AA;50% probability
E) Emily: Aa,man: Aa;100% probability

Question 18

Which statement is true of a single human gamete?

A) There are 46 chromosomes present.
B) There are two alleles per trait on each chromosome.
C) There is one allele per trait on each chromosome.
D) all of these
E) none of these

Question 19

Use the following information for this question:
Phenylketonuria is considered to be an inborn error of metabolism.It is a recessive genetic condition in which the enzyme that breaks down the amino acid phenylalanine is defective or missing.Testing of all newborns allows this condition to be detected at birth.A special diet that severely minimizes phenylalanine (e.g. ,by avoiding diet sodas and most usual sources of protein)can treat the condition.
In this scenario,two carriers of both cystic fibrosis and phenylketonuria have a child.
What is the probability that the child will have both cystic fibrosis and phenylketonuria?

A) 6.25%
B) 12.5%
C) 18.75%
D) 56.25%
E) 0%

Question 20

What is the genotype of a person with cystic fibrosis?

A) The genotype includes two mutant CFTR genes,one each on the homologous chromosomes for chromosome 7.
B) The genotype includes one mutant CFTR gene and one normal gene,one each on the homologous chromosomes for chromosome 7.
C) The genotype includes two mutant CFTR genes,both on a single homologous chromosome 7;the other homologous chromosome 7 is normal.
D) The genotype includes only one homologous chromosome 7;the second chromosome 7 is missing.
E) The genotype includes 2 additional chromosomes with the mutant CFTR gene,making a total of 25 chromosomes.

Question 21

Would a change in the nucleotide sequence of DNA change the structure of a protein?

A) One base equals one amino acid,so if there is a change in a base,it changes the amino acid,too.
B) A change in the DNA could lead to a change in the protein's amino acid sequence.This could lead to improper folding of the protein.
C) It wouldn't affect the protein;a change in the DNA sequence doesn't change the protein sequence.
D) A change in the DNA would only be caused by a change in the protein first.
E) None of the above.

Question 22

A mutation in a DNA coding region of a protein can cause

A) a change in primary structure of the protein.
B) a change in secondary structure of the protein.
C) a change in tertiary structure of the protein.
D) a change in quaternary structure of the protein.
E) All of the above.

Question 23

In the case of the Schallers,why doesn't their genotype correlate with their phenotype?

A) Although each carries a copy of a mutated CF gene,they also express a normal copy of the CF gene that renders them phenotypically normal.
B) The Schallers have only normal,nonmutated copies of the CF gene.
C) The Schallers inherited one mutated and one normal CF gene.
D) None of the above.
E) A and C.

Question 24

What is a genotype?

A) the genetic makeup of an individual
B) defined by one's phenotype
C) the same as the phenotype
D) the measureable or visual traits of an individual
E) A and B.

Question 25

An organism's _________ determines its __________.

A) phenotype;holotype
B) genotype;holotype
C) karyotype;genotype
D) genotype;phenotype
E) genotype;karyotype

Question 26

If a trait is not displayed in the phenotype,it is called

A) recessive.
B) aa.
C) Aa.
D) dominant.
E) homozygous.

Question 27

What is the possible outcome of a mutation in terms of protein function?

A) It's beneficial.
B) It's detrimental.
C) It has no effect.
D) All of the above.
E) None of the above.

Question 28

What does it mean to say that a person has a heterozygous genotype for a disease and no disease phenotype?

A) It means that the person has two copies of the disease allele.
B) It means that the person has two copies of the normal allele.
C) It means that the person exhibits the symptoms of the disease if the disease allele is recessive.
D) It means that the person does not show symptoms of the disease if the disease allele is recessive.
E) It means that the person is a carrier who has already sired children who show symptoms of the disease.

Question 29

The deletion of a codon in the gene for CF causes the CFTR protein to

A) stop being made.
B) become nonfunctional.
C) become more active.
D) become overexpressed.
E) become underexpressed.

Question 30

The most common CF allele on chromosome 7 is

A) a three-base-pair deletion.
B) a three-codon deletion.
C) a three-amino-acid deletion.
D) a single base pair deletion.
E) a frameshift mutation.

Question 31

A phenotype is

A) an inherited disorder.
B) a physical trait.
C) a genetic trait.
D) an allele descriptor.
E) a karyotype.

Question 32

If two individuals were heterozygous for freckles,which is a dominant trait,what percentage of their progeny would have freckles?

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

Question 33

A mutation in a DNA coding region of a protein can cause

A) a different amino acid at that position.
B) altered bonding between amino acids in the protein.
C) a change in the 3D shape of the protein.
D) no change in protein functionality.
E) All of the above.

Question 34

What is the significance of gene mutations in terms of protein function and clinical outcome?

A) Changes in gene sequence can alter the shape or function of a protein.
B) Analyzing specific mutations allows researchers to study overall gene function.
C) Gene mutations allow researchers to identify deficient proteins and aid in therapeutic intervention,such as in cystic fibrosis.
D) A and B.
E) All of the above.

Question 35

The appearance of an organism is known as its

A) karyotype.
B) genotype.
C) phenotype.
D) holotype.
E) physiotype.

Question 36

How is the sequence of amino acids in a protein determined?

A) The sequence of amino acids is determined by each individual base in DNA that codes for an amino acid.
B) The sequence of amino acids is not dependent on the order of bases in the DNA.
C) The amino acids are determined by codons in the DNA,which are read in 3-base increments.
D) The sequence of amino acids depends on the protein's function.
E) The sequence of amino acids is determined by the properties of each amino acid.

Question 37

People with the same cystic fibrosis alleles at the CFTR site do not always exhibit the same symptoms-some are sicker than others.Which of the following best explains this?

A) the influence of modifier genes
B) the influence of deletion genes
C) the presence of other genes that code for normal CFTR protein
D) the presence of another gene that fixes the deformed protein
E) worse symptoms in men than in women

Question 38

What is a phenotype?

A) the genetic makeup of an individual
B) a person's measurable,or observable,traits
C) the type of alleles present in an individual
D) an individual's physical appearance
E) B and D

Question 39

Use the following information for this question:
Phenylketonuria is considered to be an inborn error of metabolism.It is a recessive genetic condition in which the enzyme that breaks down the amino acid phenylalanine is defective or missing.Testing of all newborns allows this condition to be detected at birth.A special diet that severely minimizes phenylalanine (e.g. ,by avoiding diet sodas and most usual sources of protein)can treat the condition.
In this scenario,two carriers of both cystic fibrosis and phenylketonuria have a child.
What is the probability that the child will have cystic fibrosis and be a carrier for phenylketonuria?

A) 6.25%
B) 12.5%
C) 18.75%
D) 56.25%
E) 0%

Question 40

What is the most common mutation found in cystic fibrosis?

A) Three nucleotides in the CFTR gene are deleted on chromosome 3.
B) Two nucleotides are deleted in the CFTR gene on chromosome 7.
C) Three nucleotides are deleted in the CFTR gene on chromosome 7.
D) The entire gene is deleted.
E) None of the above.

Question 41

All of the following are true of alleles,EXCEPT

A) they vary in nucleotide sequence.
B) when alleles of a gene differ,the organism is said to be homozygous.
C) for some diseases,if a person has only one disease allele,they may be healthy.
D) there may be many different alleles in the population.
E) pairs of alleles reside on homologous chromosomes.

Question 42

How can someone get two different alleles of the same gene?

A) A mutation can cause a second form of a gene to be created.
B) One allele can be inherited from mom and a different allele inherited from dad.
C) They can inherit two different alleles from mom.
D) They can inherit two different alleles from dad.
E) A and B

Question 43

Which of the following statements is TRUE?

A) Males get all of their chromosomes from their fathers.
B) Females get all of their chromosomes from their mothers.
C) Females get half of their chromosomes from each parent.
D) Females get 75% of their chromosomes from their mothers.
E) Males get 75% of their chromosomes from their fathers.

Question 44

What are gametes?

A) in humans,the egg and sperm
B) reproductive cells that carry only one copy of each chromosome
C) haploid cells
D) gametes are diploid cells with chromosomes from the mother and father
E) A,B,and C

Question 45

Which of the following statements is FALSE?

A) Homologous chromosomes have the same types of genes as each other.
B) Homologous chromosomes might have the exact same alleles as each other.
C) Homologous chromosomes are assigned the same chromosome number.
D) The sizes of homologous chromosomes are very similar or identical.
E) Homologous chromosomes must have the exact same alleles as each other.

Question 46

Is a change in nucleotide sequence always detrimental?

A) Yes,it always leads to a loss of protein function.
B) It can also be beneficial.
C) It can also have no effect at all.
D) Both B and C

Question 47

In humans,a homologous chromosome pair consists of

A) one chromosome from mom and one from dad.
B) two chromosomes from mom and two from dad.
C) one chromosome from mom and two from dad.
D) 22 chromosomes from mom and 22 from dad.
E) 23 chromosomes from mom and 23 from dad.

Question 48

Humans have

A) 23 pairs of chromosomes,which include the sex chromosomes.
B) 46 pairs of chromosomes,which include the sex chromosomes.
C) 23 pairs of chromosomes,plus the sex chromosomes.
D) 46 pairs of chromosomes,plus the sex chromosomes.
E) 23 chromosomes.

Question 49

A human female has how many pairs of homologous chromosomes?

A) 46
B) 44
C) 22
D) 23
E) 48

Question 50

How many chromosomes are in a gamete?

A) 46
B) 23
C) 12
D) 1
E) 92

Question 51

One of the mutations of the CFTR gene is the result of the deletion of three consecutive nucleotides.This leads to all of the following,EXCEPT

A) one missing amino acid.
B) incorrect base pairing.
C) one missing codon.
D) a deformed protein.
E) incorrect mRNA.

Question 52

A mutation in DNA can

A) lead to a change in protein shape.
B) lead to a change in protein function.
C) lead to a shorter protein.
D) lead to a protein that is missing critical amino acids.
E) All of the above.

Question 53

How are gametes different from the rest of the body's cells?

A) Gametes are diploid,whereas other cells are haploid.
B) Gametes are sex cells.
C) Gametes are haploid,containing only one copy of each chromosome.
D) Gametes are generated from a specialized form of cell division called meiosis.
E) B,C,and D

Question 54

How many chromosomes do human sperm and egg cells have?

A) 22
B) 23
C) 46
D) 48
E) 24

Question 55

All of the following are true of mutations,EXCEPT

A) they lead to new alleles.
B) they are a source of genetic variation.
C) they are sometimes harmful.
D) they are sometimes helpful.
E) mutations always lead to the organism's death.

Question 56

How are the X and Y chromosomes in males different from other diploid cells?

A) Genes on the X and Y chromosome do not have a second copy.
B) Genes on the X and Y chromosome express an extra copy of each gene.
C) The X and Y chromosome in males preferentially express specific genes while silencing others.
D) A and C.
E) None of the above

Question 57

What are homologous chromosomes?

A) paired chromosomes that are inherited from either mother or father
B) two copies of each chromosome within a cell that are inherited from both mother and father
C) two chromosomes located within a haploid cell
D) two copies of identical chromosomes within a diploid cell
E) None of the above.

Question 58

A human male has how many pairs of homologous chromosomes?

A) 46
B) 23
C) 22
D) 44
E) 48

Question 59

You have cystic fibrosis (CF)if you have inherited

A) two normal CF alleles.
B) two normal and two defective CF alleles.
C) two normal and one defective CF alleles.
D) one normal and one defective CF allele.
E) two defective CF alleles.

Question 60

In a diploid organism

A) there are two copies of every gene,both inherited from the mother.
B) there are two copies of every gene,both inherited from the father.
C) there are two copies of every gene,one inherited from the mother and the other from the father.
D) there is one copy of every gene,randomly inherited from either mother or father.
E) there are only two alleles present in the entire population.

Question 61

During meiosis,

A) cells do not divide.
B) cells divide once.
C) cells divide twice.
D) cells double in size but do not divide.
E) cells do not divide but lose half their chromosomes.

Question 62

What is meiosis?

A) the specialized type of cellular division that generates haploid gametes
B) a type of cellular division that contains two separate divisions,ultimately leading to the separation of sister chromatids
C) a type of cellular division that aides in genetic diversity by containing both recombination and independent assortment
D) A and B
E) A and C

Question 63

What two processes occur during meiosis to aide in genetic diversity?

A) recombination and dependent assortment
B) independent assortment and recombination
C) meiosis I and II
D) All of the above.
E) None of the above.

Question 64

In human gametes,how many possible allele combinations exist?

A) 23²³
B) 46²
C) 23²
D) 46²³
E) 2²³

Question 65

Meiosis differs from mitosis in all of the following ways,EXCEPT

A) in meiosis there are two cell divisions;in mitosis there is only one.
B) meiosis only occurs in ovaries and testes.
C) meiosis results in haploid cells whereas mitosis results in diploid cells.
D) mitosis results in four cells whereas meiosis results in two.
E) meiosis results in genetically unique daughter cells whereas mitosis results in genetically identical daughter cells.

Question 66

Crossing over occurs between

A) maternal chromosomes.
B) sister chromatids.
C) nonsister chromatids.
D) paternal chromosomes.
E) homologous chromosomes.

Question 67

In humans,which process increases genetic diversity the most?

A) mutations
B) linkage
C) recombination
D) independent assortment
E) gamete fusion

Question 68

What is the process where maternal and paternal chromosomes exchange genetic material?

A) gamete fusion
B) recombination
C) independent assortment
D) meiosis
E) mitosis

Question 69

During the process of genetic recombination,

A) maternal and paternal chromosomes pair and physically exchange DNA segments.
B) crossing over occurs between two nonsister chromatids.
C) DNA segments are exchanged between two nonsister chromatids during meiosis I.
D) None of the above.
E) All of the above.

Question 70

What is the difference between meiosis I and II?

A) During meiosis I,sister chromatids separate.
B) Meiosis II produces haploid daughter cells.
C) Meiosis I begins with a haploid cell containing 23 pairs of chromosomes.
D) Meiosis II produces daughter cells that will each develop into egg or sperm.
E) B and D

Question 71

In humans,after meiosis,one diploid cell produces

A) two identical diploid daughter cells.
B) two unique haploid daughter cells.
C) four unique haploid daughter cells.
D) four identical diploid daughter cells.
E) four unique diploid daughter cells.

Question 72

What percentage of a man's chromosomes are found in a single sperm cell?

A) 25%
B) 75%
C) 100%
D) 33.3%
E) 50%

Question 73

How is genetic diversity created in meiosis I?

A) The sister chromatids line up in the middle of the cell.
B) Meiosis I results in a mixture of 46 chromosomes that are different from one another.
C) Recombination of sister chromatids occurs in meiosis I.
D) Each cell gets only one copy of each chromosome at the end of meiosis I.
E) None of the above.

Question 74

Gametes differ from other cells in the body because gametes

A) are only inherited from the mother.
B) do not carry a gene to determine gender.
C) have three copies of every gene.
D) live forever.
E) are haploid.

Question 75

A duplicated homologous chromosome pair contains how many possible alleles?

A) 2
B) 4
C) 8
D) 16
E) 32

Question 76

Sister chromatids are separated during

A) meiosis II.
B) meiosis I.
C) mitosis I.
D) mitosis II.
E) meiosis I and II.

Question 77

Sexual reproductive cells are called

A) sporozoites.
B) lymphocytes.
C) zygotes.
D) gametes.
E) conidia.

Question 78

Sister chromatids are held together at the

A) kinetochore.
B) centrioles.
C) chromosome.
D) centromere.
E) centrosome.

Question 79

All of the following are TRUE of meiosis,EXCEPT

A) recombination occurs during meiosis II.
B) the resulting cells contain 23 chromosomes.
C) there are two cell divisions.
D) one cell produces four cells.
E) homologous pairs separate during meiosis I.

Question 80

Which of the following puts the events of meiosis in the correct order?

A) chromosomes duplicate,crossing over,homologous chromosomes separate,sister chromatids separate
B) chromosomes duplicate,crossing over,sister chromatids separate,homologous chromosomes separate
C) homologous chromosomes separate,chromosomes duplicate,crossing over,sister chromatids separate
D) crossing over,chromosomes duplicate,homologous chromosomes separate,sister chromatids separate
E) crossing over,chromosomes duplicate,sister chromatids separate,homologous chromosomes separate