Deck 9: Genetic Recombination

Question 1

Suppose that a researcher is looking for met^- strains of E. coli. She compares two plates. One plate has colonies growing on complete media. The other plate has colonies growing on methionine-deficient media. How can the researcher determine which colonies are met^-?

A)by replica plating the plate with minimal media onto one with complete media
B)by streaking all individual colonies on minimal media
C)by replica plating the plate with complete media onto one with minimal media
D)by growing the bacteria in broth media that is complete

Answer 1

C

Question 2

By which molecular process do noninfective strains of bacteria acquire genes from infectious strains?

A)by nuclear division
B)by metaphase II
C)by double cross-overs
D)by meiosis

Answer 2

C

Question 3

What type of genetic recombination results from the mating of two strains of bacteria F⁺ and F^-?

A)transposition
B)plasmid genetic recombination
C)conjugation
D)histone genetic recombination

Answer 3

B

Question 4

Which type of DNA is transferred as a result of conjugation involving an Hfr strain of E. coli?

A)the F factor
B)chromosomal genes
C)eukaryotic DNA
D)the sex pilus

Question 5

"Bio" refers to a gene that governs a cell's ability to synthesize biotin from inorganic precursors. What does the designation "bio⁺" indicate?

A)that the bacterium is biologically inactive
B)that the allele is the mutant allele
C)that the bacterium is biologically active
D)that the allele is normal (i.e., wild type)

Question 6

"Thr" refers to a gene that governs a cell's ability to synthesize threonine from inorganic precursors. What does the designation "thr⁺" indicate?

A)that the bacterium is biologically inactive
B)that the bacterium is biologically active
C)that the allele is the mutant allele
D)that the allele is normal (i.e., wild type)

Question 7

What is identified through the technique of replica plating?

A)auxotrophic bacteria
B)a heterozygote
C)prototropic bacteria
D)phototropic bacteria

Question 8

What is the purpose of the sex pilus?

A)to form a gap junction and conjugate
B)to allow transfer of gametes
C)to facilitate DNA exchange
D)to stabilize a network of bacterial cells

Question 9

Which genetic factor confers upon bacteria the ability to undergo conjugation?

A)the F factor
B)the sex pilus
C)the X factor
D)the C factor

Question 10

"Met" refers to a gene that governs a cell's ability to synthesize methionine from inorganic precursors. What does the designation "met^-" indicate?

A)that the allele is normal (i.e., wild type)
B)that the bacterium is biologically active
C)that the bacterium is biologically inactive
D)that the allele is the mutant allele

Question 11

Which term refers to media that contain water, organic carbon sources, and salts, but no extra nutritional components?

A)nutritious media
B)complete media
C)minimal media
D)agar media

Question 12

Hfr cells can integrate the F factor and some genes into the bacterial chromosome. How do Hfr cells accomplish this?

A)through crossing-over
B)through mitosis
C)through meiosis
D)through prophase

Question 13

How many recombination events result from cutting and pasting four DNA backbones?

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

Question 14

"Leu" refers to a gene that governs a cell's ability to synthesize leucine from inorganic precursors. What does the designation "leu^-" indicate?

A)that the bacterium is biologically inactive
B)that the allele is the mutant allele
C)that the bacterium is biologically active
D)that the allele is normal (i.e., wild type)

Question 15

Which sentence best describes what occurs during bacterial transformation?

A)Bacteria take up pieces of DNA through infection of a virus.
B)Bacteria replicate DNA molecules.
C)Bacteria make replicate copies of one another.
D)Bacteria take up pieces of DNA that are released as other cells disintegrate.

Question 16

During conjugation, which cells are the recipients of the exogenous DNA?

A)F^- cells
B)F2 cells
C)F1 cells
D)F⁺ cells

Question 17

During bacterial conjugation, bacterial DNA with different alleles get together. What is the name of the long tubular structure that bacteria use to obtain differing alleles?

A)the sex pilus
B)the metabolic pilus
C)the flagellum
D)the asexual pilus

Question 18

Which sentence best describes what occurs during bacterial conjugation?

A)Cells exchange their entire genome.
B)Cells contact each other using a sex pilus to obtain new alleles.
C)Cells contact each other to exchange proteins.
D)Cells disrupt each other.

Question 19

What is the name of the small circles of DNA that occur in bacteria in addition to the main circular chromosomal DNA molecule?

A)plasmids
B)plastids
C)transformants
D)plasmitrons

Question 20

Suppose that two strains of E. coli-strain a (bio^- met^- leu⁺ thr⁺ thi⁺) and strain b (bio⁺ met⁺ leu^- thr^- thi^-)-conjugate. If the two strains are grown on minimal medium, what is the most likely genotype of their offspring?

A)bio⁺ met^- leu^- thr^- thi⁺
B)bio⁺ met⁺ leu⁺ thr⁺ thi⁺
C)bio⁺ met⁺ leu^- thr^- thi⁺
D)bio^- met^- leu^- thr^- thi⁺

Question 21

Suppose that an unknown organism from an alien planet is observed and found to have a diploid state only following fertilization. Meiosis follows and the majority of this organism's life is spent in a haploid state. Which multicellular organisms on Earth most closely resemble this type of life cycle strategy?

A)ferns
B)maple trees
C)humpback whales
D)some algae

Question 22

Suppose that a researcher exposes a noninfective form of the bacterium Streptococcus pneumoniae to heat-killed cells of an infective strain. Which process of genetic exchange is most likely to occur between the strains?

A)conjugation
B)re-infection
C)transduction
D)transformation

Question 23

Who discovered transformation?

A)Gregor Mendel
B)Fred Griffith
C)Elie L. Wollman
D)Joshua Lederberg

Question 24

What term refers to the series of events that begins with an infection of one cell and ends with the release of progeny phages from broken or open cells?

A)the lysogenic cycle
B)the lytic cycle
C)the citric acid cycle
D)the Krebs cycle

Question 25

Which of the following is an advantage of sexual reproduction over asexual reproduction?

A)Sexual reproduction mixes genetic information into a new combination in the next generation.
B)Sexual reproduction ensures a greater number of progeny.
C)Sexual reproduction keeps the number of chromosomes constant more effectively.
D)Sexual reproduction requires an interaction between two individuals.

Question 26

Suppose that an unknown organism from an alien planet is observed and found to have a diploid state in every other generation and to result from fertilization. The haploid state is able to grow into a gametophyte-like structure. Which life cycle strategies does this alien organism closely mimic?

A)those of all plants and some fungi
B)those of fungi and algae
C)those of algae and animals
D)those of plants and animals

Question 27

What sort of phage is bacteriophage lambda considered to be?

A)a virulent phage
B)a plant phage
C)an animal phage
D)a temperate phage

Question 28

Which pattern of diploid and haploid phases reflects the life cycle of animals?

A)alternation between haploid and diploid generations
B)one haploid generation followed by two diploid generations
C)two haploid generations followed by a diploid generation
D)a single generation that limits the haploid state to gametes, while the rest of the organism is diploid

Question 29

Which of the following processes is used by plants to generate gametes from gametophytes?

A)conjunction
B)mitosis
C)meiosis
D)transduction

Question 30

Which organisms undergo alternation between haploid and diploid generations?

A)all plants
B)all animals
C)all bacteria
D)all fungi

Question 31

In terms of meiosis, what is the essential difference between the life cycle of animals and the life cycle of plants?

A)Plants alternate between haploid and diploid generations.
B)Animals do not have a haploid phase.
C)Animals have a dominant haploid phase.
D)Plants alternate between diploid and polyploid generations.

Question 32

Which term refers to a virus in the lysogenic cycle that is fully integrated into the host genome?

A)virulent phage
B)infectious phage
C)tempered phage
D)prophage

Question 33

What do bacterial cells do in transduction?

A)They take up pieces of DNA through the use of a virus.
B)They replicate DNA molecules.
C)They make replicate copies of one another.
D)They take up pieces of DNA that are released as other cells disintegrate.

Question 34

Which phrase best describes a homologous chromosome pair?

A)two chromosomes that have the same genes in the same order, but have different alleles
B)two chromosomes that have different genes in the same order, and possibly have different alleles of some genes
C)two chromosomes that have the same alleles of the same genes in the same order
D)two chromosomes that have different alleles of the same genes arranged in a different order

Question 35

Which of the following outcomes is more likely to occur in an organism undergoing sexual reproduction than in an organism undergoing asexual reproduction?

A)a rapid increase in population size
B)a decrease in genetic diversity
C)an increase in genetic diversity
D)a rapid colonization of new niches

Question 36

How can bacterial cells that cannot readily pick up DNA molecules from their surroundings be forced to do so?

A)by double crossing-over
B)by crossing-over
C)by artificial transformation
D)by constriction

Question 37

For some virulent phages, fragments of the host DNA may be included in the heads as the viral particles assemble, thus providing the basis for transduction of bacterial genes during the next cycle of infection. What is the name of this mechanism?

A)generalized transduction
B)transformation
C)transmutation
D)specific transduction

Question 38

Which phrase best describes sister chromatids?

A)two chromosomes having an identical DNA sequence
B)two chromosomes having different alleles of the same genes arranged in a different order
C)two chromosomes having the same alleles of the same genes in a different order
D)two chromosomes having the same genes in the same order, but having different alleles

Question 39

Which pattern of diploid and haploid phases reflects the life cycle of plants?

A)alternation between haploid and diploid generations
B)one haploid generation followed by two diploid generations
C)two haploid generations followed by a diploid generation
D)a single generation that limits the haploid state to gametes, while the rest of the organism is diploid

Question 40

Which pattern of diploid and haploid phases reflects the life cycles of some fungi and algae, but NOT the life cycles of plants or animals?

A)two haploid generations followed by a diploid generation
B)one haploid generation followed by two diploid generations
C)a life cycle that limits the diploid state to a single cell produced by fertilization
D)alternation between haploid and diploid generations

Question 41

In what way is the process of fertilization random?

A)in the type of gamete fertilized
B)in the selection of which gametes fuse
C)in the recombination of chromosomes
D)in the number of chromosomes involved

Question 42

Which of the following types of genetic material undergo recombination during meiosis?

A)sister chromatids
B)sister chromatids and homologous chromosomes
C)all four chromatids
D)homologous chromatids

Question 43

Suppose that an organism has the same life strategy as a maple tree. When will the synaptonemal complex be observed?

A)only in a unicellular haploid phase
B)in each generation
C)only in a multicellular haploid phase
D)only in alternating generations

Question 44

Spore is another name for gamete.

Question 45

Which chromosomal arrangements are assured by the gametes that are produced by independent assortment?

A)chromosomes containing genes from the paternal and maternal chromosomes
B)some paternal chromosomes and some maternal chromosomes
C)only maternal chromosomes
D)only paternal chromosomes

Question 46

What would be the outcome, in genetic terms, of recombination between sister chromatids?

A)Genetic diversity is unaffected.
B)Genetic diversity is decreased.
C)Genetic diversity is increased.
D)Nonhomologous chromatids are formed.

Question 47

When researchers exposed Volvox carteri to oxidative stress, what was the result?

A)induction of sex-related genes
B)induction of genes for colour
C)mating
D)death

Question 48

When do homologous chromosomes undergo recombination?

A)during anaphase
B)during prophase
C)during telophase
D)during metaphase

Question 49

What is the main difference between bacterial and eukaryotic transposons?

A)Eukaryotic transposons sometimes transpose using RNA and bacterial transposons do not.
B)Eukaryotic transposons carry genes and bacterial transposons do not.
C)Bacterial transposons contain inverted repeats and eukaryotic transposons do not.
D)Bacterial transposons sometimes transpose using RNA and eukaryotic transposons do not.

Question 50

Which phrase best describes the result of meiosis?

A)the generation of four haploid cells
B)the generation of four diploid cells
C)the generation of two diploid cells and two haploid cells
D)the generation of two diploid cells

Question 51

Which of the following genes are contained in bacterial insertion sequences?

A)recombinase
B)tetracycline resistance gene
C)ampicillin resistance gene
D)transposase

Question 52

Bacterial transposons often carry genes for which feature?

A)formation of flagella
B)formation of antibiotic resistance
C)formation of the sex pilus
D)formation of a capsule

Question 53

Which stage of meiosis is characterized by DNA condensation into compact chromosomes?

A)prophase I
B)prophase II
C)prometaphase I
D)anaphase I

Question 54

Suppose that a species has 42 pairs of chromosomes. Which of the following values represents the number of combinations of maternal and paternal chromosome combinations that will be sorted to the poles?

A)2⁴²
B)2²¹
C)42²
D)21²

Question 55

Which of the following always results from recombination at the synaptonemal complex?

A)a random number of changed chromatids vs. unchanged chromatids
B)four unchanged chromatids
C)two changed chromatids and two unchanged chromatids
D)four changed chromatids

Question 56

Haploid organisms growing via mitosis from spores are called gametophytes.

Question 57

Which of the following best describes the sex chromosomes?

A)They are non-homologous.
B)They are completely homologous.
C)They are heterozygous.
D)They are partially homologous, but also have unique regions.

Question 58

Which phrase describes how identical twins can result?

A)from the fusion of two paternal gametes with a single maternal gamete that then divides
B)from a lack of chromosomal separation during meiosis, resulting in gametes that are diploid and do not need to be fertilized
C)from the fusion of two sets of identical gametes
D)from a division of a zygote into two separate cells that develop into two separate embryos

Question 59

Prokaryotic cells can undergo meiosis.

Question 60

Which of the following is among the results of nondisjunction?

A)a change in the status of a daughter cell from diploid to haploid
B)a failure of spindle fibres to separate a homologous pair of chromosomes
C)one pole receiving neither member of a homologous pair of chromosomes
D)a change in the status of a daughter cell from haploid to diploid

Question 61

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
synapsis

Question 62

Crossing-over is limited to a single occurrence for a chromosome.

Question 63

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
gametes

Question 64

List and briefly explain the three ways in which genetic variability is increased during meiosis.

Question 65

Haploid cells have homologous chromosomes.

Question 66

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
haploid

Question 67

Explain the purpose of meiosis.

Question 68

Describe the two stages in meiosis where the most genetic recombination occurs.

Question 69

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
meiosis

Question 70

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
allele

Question 71

Even if chromosomes are not a perfect match, pairing centres sometimes allow synapsis.

Question 72

Match the events listed below to the following processes. A process may be used once, more than once, or not at all.
a.prophase I
b.prometaphase I
c.metaphase I
d.anaphase I
e.telophase I
f.prophase II
g.prometaphase II
h.metaphase II
i.anaphase II
j.telophase II
Nuclear envelope reforms in all species.

Question 73

The mechanisms that control the number of cross-over events in a cell have been well characterized.

Question 74

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
fertilization

Question 75

Compare the functions of meiosis I and II in the overall generation of gametes.

Question 76

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
somatic cells

Question 77

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
chiasmata

Question 78

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
zygote

Question 79

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
sexual reproduction

Question 80

Match each term with its correct definition.
a.cell division that is modified to generate haploid cells
b.haploid products of meiosis
c.matching of homologous pairs of chromosomes during prophase I
d.term used to describe cells having two sets of chromosomes
e.diploid body cells that do not undergo meiosis
f.term used to describe cells having a single set of chromosomes
g.life strategy that involves fusion of haploid gametes from two source organisms to form a diploid cell
h.another name for cross-over sites
i.variant of a particular gene having a slightly different DNA sequence than another variant of the same gene
j.diploid product of gamete fusion
k.process of gamete fusion
diploid