Deck 25: Sexual Reproduction,meiosis,and Genetic Recombination

Question 1

How many different types of gametes can be produced by an individual with genotype AaBBCcDdEe,if all five genes are on different chromosomes?

A)4
B)5
C)10
D)16
E)25

Answer 1

D

Question 2

Fungi produce spores by which of the following processes?

A)binary fission
B)mitosis
C)meiosis
D)gene conversion
E)cloning

Answer 2

C

Question 3

Fungi produce gametes by which of the following processes?

A)binary fission
B)mitosis
C)meiosis
D)gene conversion
E)cloning

Answer 3

B

Question 4

The genotype of a tall,yellow pea plant is TtYy.How many different types of gametes can this individual produce if the tall and yellow genes are on different chromosomes?

A)1
B)2
C)4
D)5
E)8

Question 5

Which of the following applies to organisms,particularly plants and fungi,that have distinct haploid and diploid phases of their life cycles?

A)polyploidy
B)aneuploidy
C)alternation of generations
D)asexual propagation
E)regeneration

Question 6

New combinations of genetic material give rise to genetic variability in sexually reproducing organisms through

A)crossover events between nonsister homologous chromatids.
B)crossover events between sister chromatids.
C)egg and sperm genetic recombination from distinct individuals.
D)egg and sperm genetic recombination from one individual in which crossing over and independent assortment of homologues has occurred.
E)A,C,and D all contribute to genetic variability.

Question 7

The protein shugoshin is crucial for meiosis I,because it

A)promotes chiasmata formation.
B)condenses chromosomes.
C)decondenses chromosomes.
D)protects centromere cohesins from degradation by separase.
E)attaches microtubules to kinetochores.

Question 8

Alternative forms of a gene are known as

A)alleles.
B)genes.
C)loci.
D)spores.
E)haplotypes.

Question 9

A black Angus bull named Charlie is heterozygous (Bb)for coat color (B = black and b = brown).Charlie's black coat color is his

A)genotype.
B)heterozygous state.
C)gene conversion state.
D)phenotype.
E)homozygous state.

Question 10

Meiosis I results in the formation of

A)two diploid cells.
B)four diploid cells.
C)two haploid cells.
D)four haploid cells.
E)one quadraploid cell.

Question 11

In a cross of two individuals,both of whom have genotype AaBb,what proportion of the offspring are expected to have the genotype AABB?

A)9/16
B)1/16
C)1/2
D)3/16
E)6/16

Question 12

Meiosis involves

A)one round of chromosomal replication and one nuclear division.
B)one round of chromosomal replication and two nuclear divisions.
C)two rounds of chromosomal replication and one nuclear division.
D)two rounds of chromosomal replication and two nuclear divisions.
E)the number of rounds of chromosomal replication and nuclear divisions depends on whether the cell is haploid or diploid.

Question 13

Meiosis most resembles mitosis in

A)the phases of meiosis I.
B)the phases of meiosis II.
C)meiosis I,except for the pairing of homologues.
D)meiosis II,except for the pairing of homologues.
E)all phases of meiosis I and meiosis II.

Question 14

The stage of prophase I in which mammalian oogenesis can arrest for years is

A)leptotene.
B)zygotene.
C)pachytene.
D)diplotene.
E)diakinesis.

Question 15

How many chromatids are present in prophase I in a diploid cell in which 2n = 12?

A)6
B)12
C)24
D)48
E)Can't tell-more information is required.

Question 16

In humans,the volume of an egg is 100 times the volume of a sperm.Compared to the amount of chromosomal DNA in an egg,the amount of chromosomal DNA in a sperm is

A)variable but usually less than one-hundredth that of the egg.
B)exactly one-hundredth that of the egg.
C)one-fourth that of the egg.
D)one-half that of the egg.
E)equal to that of the egg.

Question 17

Which of the following types of organisms is always haploid?

A)bacteria
B)fungus
C)Drosophila
D)ferns
E)humans

Question 18

Individuals with Turner syndrome (monosomy X)have only one sex chromosome-a single X chromosome.Such individuals are produced when nondisjunction results in a gamete with no sex chromosome,which subsequently fuses with a normal gamete.What would be the sex chromosome complement of an individual produced by fusion of a normal gamete with the gamete that ended up with the extra chromosome missing from the Turner syndrome patient?

A)XXX
B)XXY
C)XYY
D)XY
E)Either A or B would be a possible chromosome complement.

Question 19

Which of the following is true about mitosis or meiosis?

A)Homologues are separated in prophase I of meiosis.
B)Homologues are separated in prophase II of meiosis.
C)Homologues are separated in prophase of mitosis.
D)Sister chromatids are separated in prophase I of meiosis.
E)Sister chromatids are separated in anaphase II of meiosis.

Question 20

A black Labrador retriever named JD is heterozygous (Bb)for coat color (B = black and b = brown).Bb is JD's

A)genotype.
B)heterozygous state.
C)gene conversion state.
D)phenotype.
E)homozygous state.

Question 21

Each of the following transfers DNA into bacteria except

A)conjugation.
B)infection.
C)transduction.
D)transformation.
E)All transfer DNA into bacteria.

Question 22

One parent carries a dominant allele (A^L)that is lethal in early life in homozygotes.The other parent is homozygous for the wild type allele (A⁺)of the same gene.What is the expected dominant:wild type phenotype ratio for their offspring?

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

Question 23

During bacterial conjugation,interrupted matings yielded the following information: leu 10 minutes,arg 8 minutes,str 15 minutes,and amp 12 minutes.Based on this information,the order of the genes,beginning at the origin,is

A)amp-arg-leu-str.
B)str-amp-leu-arg.
C)leu-arg-str-amp.
D)arg-amp-leu-str.
E)arg-leu-amp-str.

Question 24

Homologous chromosomes are held together by

A)a synaptonemal complex.
B)centromeres.
C)kinetochores.
D)spindle poles.
E)bouquets.

Question 25

Each of the following is an activity of RAD51 or the DNA with which it interacts except

A)RAD51 appears in cells at the time of recombination.
B)RAD51 coats single-stranded DNA.
C)RAD51-coated DNA interacts with double-stranded DNA.
D)RAD51-coated DNA moves along target DNA until it finds a complementary sequence.
E)All are RAD51 or RAD51-DNA activities.

Question 26

Reproduction of Komodo dragons by parthenogenesis involves

A)conjugation.
B)transformation.
C)self-fertilization.
D)homologous recombination.
E)spore formation.

Question 27

Each of the following is associated with F factor transfer from an F⁺ bacterium to an F⁻ bacterium except

A)transfer involves conjugation.
B)transfer of the plasmid begins at the plasmid origin of transfer.
C)transfer of the plasmid converts the original F⁺ cell to an F⁻ cell.
D)following transfer,the F factor can become integrated into the F⁻ cell genome to generate an Hfr cell.
E)All the above are associated with the F factor transfer.

Question 28

The synaptonemal complex becomes fully developed during which stage of prophase I?

A)leptotene
B)zygotene
C)pachytene
D)diplotene
E)diakinesis

Question 29

What is the distribution of parental chromosomes in each of the four haploid cells produced by meiosis II?

A)100% maternal or paternal chromosomes
B)a 75%:25% mix of maternal and paternal chromosomes
C)a 50%:50% mix of maternal and paternal chromosomes
D)a random mix of maternal and paternal chromosomes
E)The distribution depends on whether the organism is haploid or diploid.

Question 30

The genes along a particular linear chromosome are illustrated in the figure above.The frequency of crossover events between these loci will be least frequent for genes

A)a and b.
B)b and c.
C)c and d.
D)d and e.
E)a and e.

Question 31

Each of the following sentences is true regarding homologous recombination except

A)The frequency of recombination is uniform across the genome.
B)Homologous recombination involves RecA in prokaryotes and RAD51 in eukaryotes.
C)Homologous recombination resolves the repaired strands using a Holliday junction.
D)Homologous recombination involves a process known as homology searching.
E)Homologous recombination involves the formation of a synaptonemal complex.

Question 32

A bacterial cell in which the F plasmid is integrated into the chromosome is known as

A)an F^- cell.
B)an F⁺ cell.
C)an F' cell.
D)an Hfr cell.
E)None of the above.

Question 33

Crossing over between the A and B genes in a parental cell containing an AB chromosome and an ab chromosome yields which of the following ratios of parental:recombinant gametes?

A)100:0
B)75:25
C)50:50
D)25:75
E)The ratio depends on whether the parental cell is male or female.

Question 34

You wish to confirm that gene X is associated with the F plasmid of your bacterial strain.To accomplish this using bacterial conjugation,you should conjugate your strain with a compatible bacterial strain that is

A)an Hfr strain.
B)another F⁺ strain.
C)an F' strain.
D)an F⁻ strain.
E)the same F⁺ strain.

Question 35

The sporophyte form of a moss is

A)haploid.
B)diploid.
C)tetraploid.
D)aneuploid.
E)either haploid or diploid.

Question 36

When studying Drosophila genetics,Morgan found that the haploid chromosome number equals the number of

A)bouquets.
B)linkage groups.
C)centromeres.
D)haploid gametes.
E)cohesins.

Question 37

The DNA sequence of two alleles of the same gene can differ by

A)approximately 100 continuous base pairs.
B)approximately 100 base pairs scattered throughout the gene.
C)three base pairs (one coding triplet).
D)one base pair.
E)no base pairs; allele sequences can be identical.

Question 38

For three genes known to be on the same chromosome,you obtain the following percentages for recombination events.What is the order of genes on this chromosome?
no observable recombination 30%
Between A and B 15%
Between B and C 35%
Between A and C 20%

A)ABC
B)ACB
C)BAC
D)BCA
E)The gene order cannot be determined from this information.

Question 39

Synapsis between chromosomes in some species is promoted by special DNA sequences known as

A)centromeres.
B)telomeres.
C)pairing sites.
D)chiasmata.
E)bouquets.

Question 40

In mosses and fungi,the process of meiosis produces

A)egg cells.
B)hybrids.
C)spores.
D)sperm cells.
E)oocytes.

Question 41

The benefit of sexual reproduction is the production of genetic ________ in offspring.

Question 42

In analyzing data for crosses involving two genes,Mendel discovered not only that these alleles separate from each other when examining one trait but also that the alleles of a second trait will separate from each other without regard to those of the first trait.This observation was the basis of Mendel's law of ________.

Question 43

In analyzing data for crosses involving one gene,Mendel discovered that alleles are discrete entities,and that they are separated during formation of gametes.This was the basis of Mendel's law of ________.

Question 44

________ is the mechanism by which some organisms,such as Komodo dragons,can develop eggs into zygotes without sperm.

Question 45

A structure consisting of two homologous chromosomes bound together so tightly during the first meiotic prophase that they behave as a single unit is called a ________.

Question 46

The condition of a zygote with three copies of a chromosome is known as ________.

Question 47

Diploid human cells contain 22 homologous chromosomes and a pair of ________.

Question 48

________ is the term used to describe the condition of a cell containing a chromosome number that is not a multiple of the haploid number.

Question 49

A mishap in chromosomal partitioning during meiosis is referred to as ________.

Question 50

Metaphase II arrest is mediated by ________,a biochemical activity present in mature eggs.

Question 51

The designation of YyWw for a heterozygous pea plant is the plant's ________.

Question 52

A genetic cross was performed with two pea plants both with green,wrinkled seeds.Of the resulting offspring,75% had green,wrinkled seeds and 25% had green,smooth seeds (W = wrinkled; w = smooth).With regard to wrinkled versus smooth seeds,the parental plants must have been ________.

Question 53

The pairing of homologous chromosomes during meiosis I is known as ________.

Question 54

In an individual pea plant,the visible characteristics of yellow and wrinkled seeds are the plant's ________.

Question 55

The observation by Masui that cytoplasm from a mature egg injected into an immature oocyte stimulated meiosis led to the identification of ________.

Question 56

Meiosis I is known as a ________ division because of what happens to the chromosome number.

Question 57

________ chromosomes pair during ________ of meiosis.

Question 58

DNA ________ accounts for the ability of chromosomes to undergo synapsis.

Question 59

Most cases of Down syndrome are caused by three copies of chromosome number ________.

Question 60

In meiosis in females,only one haploid cell develops into an egg.The remaining haploid products of meiosis are ________,which usually degenerate.

Question 61

You mate a squash with the genotype AAbb with a squash with the genotype aaBB.The resulting F₁ squash are all AaBb.After mating two F₁ squash,you obtain an F₂ generation of squash as follows: ("-" = either allele)
$$\begin{array} { l r } A -\quad B - & 5 \\A - \quad bb & 45 \\a a\quad B - & 47 \\aa \quad bb & 3 \\\hline \text { Total } & 100\end{array}$$
a)What does this tell you about assortment of the two traits?
b)What could account for the distribution obtained?

Question 62

You are interested in mapping the relative positions of three genes in the E.coli genome and have access to several cell types to use for the mapping:
a)Describe F^?,F⁺,Hfr,and F' bacterial cell types.
b)How would you use one or more of these cell types to map genes A,B,and C in the E.coli genome?
c)If you found that the results were A = 10,B = 5,and C = 3 (in the correct units),what could you conclude about the order and proximity of the three genes?

Question 63

You are investigating two temperature-sensitive mutant cells.In one,you can inactivate shugoshin activity by raising the temperature slightly at the start of meiosis.In the other,you can similarly inactivate separase activity by raising the temperature.How would the two cells be affected by inactivating these proteins?

Question 64

You suspect a cell that is capable of forming gametes might be carrying a gene that makes it defective in homologous recombination.Design an experiment to assess its homologous recombination capability.