Deck 2: Chromosomes and Cellular Reproduction

Question 1

Which of the following occurs during prometaphase?

A)The chromosomes align in a single plane.
B)DNA is replicated.
C)Microtubules attach to the kinetochores.
D)Mitotic spindles form.
E)The two sister chromatids separate.

Answer 1

C

Question 2

The process of splitting the cytoplasm, which separates one cell into two, is termed:

A)cytokinesis.
B)mitosis.
C)anaphase.
D)diakinesis.
E)fusion.

Answer 2

A

Question 3

Prokaryotic chromosomes do NOT have telomeres because they:

A)do not go through mitosis.
B)do not go through DNA replication.
C)are in the cytoplasm.
D)are circular.
E)have no centromeres.

Answer 3

D

Question 4

Which of the following statements is FALSE?

A)Errors in chromosome separation are rarely a problem for an organism.
B)Errors in chromosome separation can result in a miscarriage.
C)Errors in chromosome separation can result in cancer.
D)Errors in chromosome separation can result in a child with severe handicaps.
E)Errors in chromosome separation can cause numerous problems for an organism.

Question 5

Which of the following pairs are BOTH prokaryotes?

A)Eubacteria and higher plants
B)Archaea and eubacteria
C)Higher animals and archaea
D)Viruses and higher animals
E)Humans and eubacteria

Question 6

Which statement is TRUE based on our current understanding?

A)Eubacteria are not closely related to either archaea or eukaryotes.
B)Archaea are more closely related to eukaryotes than they are to eubacteria.
C)Eukaryotes are more closely related to eubacteria than they are to archaea.
D)Viruses are more closely related to prokaryotes than they are to eukaryotes.
E)Eubacteria, archaea, and eukaryotes are all equally related.

Question 7

The highly organized internal scaffolding of the nucleus is called the:

A)histone complex.
B)spindle microtubules.
C)nuclear cohesion.
D)nuclear matrix.
E)nuclear envelope.

Question 8

In order to be functional, a eukaryotic chromosome requires all of the following EXCEPT:

A)a centromere.
B)origins of replication.
C)a plasmid.
D)telomeres.
E)A centromere and origins of replication are both correct.

Question 9

In eukaryotes, chromosomes do NOT contain:

A)ribosomes.
B)chromatin.
C)proteins.
D)histones.
E)DNA.

Question 10

Diploid cells are cells with _____ chromosomes.

A)a single set of
B)circular
C)two sets of
D)many sets of
E)three sets of

Question 11

In prokaryotes, replication usually begins at a specific place on the chromosome called the:

A)binary fission site.
B)origin of replication.
C)origin of mitosis.
D)anchoring site.
E)kinetochore.

Question 12

Which of the following does NOT occur during the G₂ phase of the cell cycle?

A)The G₂/M checkpoint is reached.
B)DNA replication and error checking is completed.
C)The cell completes preparation for mitosis.
D)The cell divides.
E)None of above answers is correct.

Question 13

Pea plants have seven different pairs of chromosomes.The nucleus of a megaspore in a pea ovary would contain how many chromosomes?

A)3
B)7
C)14
D)21
E)30

Question 14

During anaphase of mitosis, which of the following occurs?

A)Sister chromatids separate from each other.
B)Homologous chromosomes separate from each other.
C)The spindle-assembly checkpoint insures that each chromosome is properly aligned.
D)The condensed chromosomes relax.
E)Spindle microtubules anchor to kinetochores.

Question 15

The attachment point on the chromosome for spindle microtubules is the:

A)telomere.
B)centromere.
C)origin of replication.
D)sister chromatid.
E)allele.

Question 16

Pea plants have seven different pairs of chromosomes.A nucleus in the pea endosperm contains how many chromosomes?

A)3
B)7
C)14
D)21
E)30

Question 17

A dividing eukaryotic cell is treated with a drug that inhibits the activity of the spindle-attachment checkpoint.At which cell cycle stage would you predict that the cell would be blocked?

A)G₁
B)S
C)G₂
D)Mitosis (metaphase)
E)Mitosis (telophase)

Question 18

If a healthy cell passes the G₁/S checkpoint:

A)it will enter the G₀ stage of the cell cycle.
B)DNA will be replicated.
C)it will not divide.
D)it will proceed immediately to cytokinesis.
E)it will die.

Question 19

Which of the following statements is FALSE?

A)Generally, chromosomes of prokaryotes are circular.
B)Prokaryotes usually have a single molecule of DNA.
C)Generally, chromosomes of eukaryotes are circular.
D)Eukaryotes usually have multiple chromosomes.
E)Eukaryote chromosomes are usually linear.

Question 20

Pea plants have seven different pairs of chromosomes.A chromosome with a centromere at the very end is called :

A)submetacentric.
B)metacentric.
C)acrocentric.
D)acentric.
E)telocentric.

Question 21

To provide food for the developing embryo, a tissue called endosperm is produced through double fertilization.Endosperm has a ploidy of:

A)1n.
B)2n.
C)3n.
D)4n.
E)5n.

Question 22

The complex of DNA and histone proteins that makes up the eukaryote chromosome is called:

A)cohesion.
B)chromatin.
C)microtubules.
D)centromere.
E)None of the answers is correct.

Question 23

In humans how many chromosomes will be seen in a polar body derived from a primary oocyte?

A)23
B)46
C)92
D)12
E)None of the answers is correct.

Question 24

A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42).As in humans, sex chromosomes determine sex: XX in females and XY in males.What is the total number of chromosomes present in the cell during metaphase I of meiosis?

A)21
B)42
C)84
D)126
E)168

Question 25

A pollen grain that lands on a stigma grows a pollen tube to deliver _____ (how many?)sperm to the ovary.Fusion of a sperm with an egg produces a _____ n cell, called a _____.

A)one; 1; zygote
B)two; 1; megasporocyte
C)two; 2; zygote
D)one; 2; microsporocyte
E)one; 2; megasporocyte

Question 26

A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42).As in humans, sex chromosomes determine sex: XX in females and XY in males.What is the total number of chromosomes in a polar body cell from a rat?

A)21
B)40
C)41
D)42
E)84

Question 27

What might be the result if breakdown of the shugoshin protein were premature?

A)The cohesion protein would hold the chromosome arms together longer.
B)The separation of homologous chromosomes would occur prematurely.
C)The separation of sister chromatids would occur prematurely.
D)Spindle fibers wouldn't form.
E)Sister chromatids would never separate.

Question 28

The figure shows chromosomal separation taking place.The letters stand for genes; capital and lowercase stand for different alleles.The diploid chromosome number in this organism is four.What process is shown?

A)Anaphase of mitosis
B)Telophase of meiosis I
C)Anaphase of meiosis I
D)Telophase of mitosis
E)Anaphase of meiosis II

Question 29

Why is mitosis important within the cell cycle?

Question 30

Suppose that a diploid cell contains eight chromosomes (2n = 8).How many different combinations in the gametes are possible?

A)2
B)4
C)8
D)16
E)64

Question 31

What process is unique to plants?

A)Meiosis
B)Double fertilization
C)Crossing over
D)Haploid gametes
E)Spermatogenesis

Question 32

What evidence is there that viruses evolved after, not before, cells?

Question 33

In a flowering plant, the male part of the flower (the stamen)produces haploid microspores that divide by _____ to produce sperm.

A)mitosis
B)meiosis
C)gametogenesis
D)spermatogenesis
E)fertilization

Question 34

In the flowering plants, diploid cells in the stamen undergo meiosis and directly produce four haploid:

A)sperm.
B)eggs.
C)microspores.
D)polar nuclei.
E)tube nuclei.

Question 35

Which of the following statements is TRUE concerning the DNA of bacterial cells?

A)It is complexed with histone proteins.
B)It contains a single telomere.
C)It has a centromere with a kinetochore.
D)It is surrounded by a nuclear envelope.
E)It is usually circular.

Question 36

List and briefly describe three major cell cycle checkpoints.For each checkpoint, predict the consequences if the checkpoint failed to work properly.

Question 37

A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42).As in humans, sex chromosomes determine sex: XX in females and XY in males.What is the total number of telomeres in a rat cell in G₂?

A)21
B)42
C)84
D)126
E)168

Question 38

Explain why mitosis does not produce genetic variation and how meiosis leads to the production of tremendous genetic variation.

Question 39

Microscopy to look at a cell's chromosomes is often done when the cell is in mitotic metaphase.For example, karyotypes that extract chromosomes from a single cell and photograph them to look for abnormalities are done on metaphase, rather than interphase, cells.Why?

Question 40

A dog has a diploid chromosome number of 78.How many separate DNA molecules should be present at metaphase of mitosis?

A)39
B)78
C)156
D)4
E)None of the answers is correct.

Question 41

What events during sexual reproduction are significant in contributing to genetic diversity?

Question 42

Which of the following is a key difference in the life cycles of higher animals and higher plants (angiosperms)?

A)Gametes are produced by animals, but plants produce diploid spores that act as gametes and undergo fertilization.
B)In animals the zygote is produced by the fusion of haploid sperm and eggs, but in plants the zygote is produce by fusion of a haploid sperm and a diploid egg producing a 3N cell.
C)In animals there is a double fertilization, while in plants only one fertilization event occurs.
D)In animals the immediate products of meiosis are gametes, while in plants the immediate products are haploid spores.
E)Animals have a multicellular gametophyte, while plants produce single cell gametes.

Question 43

What is one feature of meiosis that produces genetic variability in gametes? In two or three sentences, explain how this feature causes genetic uniqueness.

Question 44

Describe what is happening to chromosomes during prophase I of meiosis.

Question 45

Describe the difference between G₁ and G₂ of the cell cycle.

Question 46

(a)Describe the changing role of cohesin during the mitotic cell cycle.(b)Explain the importance of regulation of cohesin activity to normal cell division.

Question 47

List two differences and two similarities between mitosis and meiosis.

Question 48

Describe the difference between the centromere and kinetochore.

Question 49

Describe the difference between homologous chromosomes and sister chromatids.

Question 50

What is the type of chromosome where the centromere is located in the middle of the chromosome producing arms of equal length?

A)Metacentric
B)Telocentric
C)Submetacentric
D)Acrocentric
E)Prokaryotic

Question 51

Describe the difference between meiosis I and meiosis II.

Question 52

Assume that a species has a diploid chromosome number of 20.How many double-stranded DNA molecules would you expect to see at prophase of mitosis in this species?

A)5
B)10
C)20
D)40
E)80

Question 53

What are some of the main differences between prokaryotic and eukaryotic cells?

Question 54

In which stage of the cell cycle does most DNA replication occur in eukaryotes?

A)G₁
B)G₂
C)S
D)Prophase of mitosis
E)G₀

Question 55

Describe the difference between the sporophyte and gametophyte.

Question 56

(a)Compare and contrast spermatogenesis and oogenesis in animals.For each process, be sure to include information about division of the nucleus, allocation of chromosomes to the various products, and division of the cytoplasm.(b)Why is the difference in cytoplasmic division between spermatogenesis and oogenesis important to reproduction, considering the different roles of sperm and egg in reproduction?

Question 57

In a higher animal, how many secondary oocytes could be produced from 20 primary oocytes?

A)5
B)10
C)20
D)40
E)80

Question 58

What is a major function of telomeres?

A)To serve as attachment points for the kinetochore protein complex
B)To stabilize the ends of chromosomes
C)To attach to the spindle fibers during mitosis
D)To keep chromosomes circular
E)To act as origins of DNA replication

Question 59

The cells illustrated below belong to a species with a diploid chromosome number of four.Which stage of mitosis or meiosis is each cell in?

Question 60

During prophase I of meiosis, crossing over is indicated by what microscopically visible structure?

Question 61

A cell has a diploid or 2N chromosome number of 24 in its somatic cells.How many chromatids would you expect to see in G₂?

A)12
B)24
C)48
D)6
E)96

Question 62

What is the special class of proteins that is associated with the DNA of eukaryotic chromosomes and forms a complex called chromatin?

A)Cohesins
B)Histones
C)Cytokins
D)Nuclear binding proteins
E)Centromeres

Question 63

Which of the following statements about meiosis is FALSE?

A)Homologous chromosomes separate from each other during anaphase I.
B)Sister chromatids separate from each other during anaphase II.
C)Crossing over takes place during prophase I.
D)DNA replication occurs between the first and second divisions.
E)The chromosome number is reduced by one-half at the end of the first division.

Question 64

The normal function of shugoshin during meiosis involves:

A)attaching spindle fibers to the kinetochores.
B)holding homologous chromosomes together until they separate at anaphase I.
C)keeping cohesin from being broken down in the centromere regions.
D)holding sister chromatids together until they separate at anaphase I.
E)allowing crossing over to only occur at specific chromosomal regions.

Question 65

Three primary oocytes can lead to _____ eggs while three secondary spermatocytes can lead to _____ sperm.

A)12; 9
B)3; 3
C)3; 6
D)6; 12
E)6; 6

Question 66

Which of the following events occurs during meiosis I but not during meiosis II?

A)Separation of sister chromatids
B)The cytoplasm divides
C)Individual chromosomes line up on the metaphase plate
D)Chromosomes condense
E)The two chromosomes of each homologous pair separate

Question 67

In animals, what is a diploid cell which can directly initiate meiosis I and produce two haploid cells?

A)Microspore mother cell
B)Secondary oocyte
C)Secondary spermatocyte
D)Primary spermatocyte
E)First polar body

Question 68

In the life cycle of a higher plant (angiosperm), the female part of the flower undergoes meiosis and directly produces:

A)four functional microspores.
B)one functional microspore.
C)one functional egg.
D)the endosperm.
E)one functional megaspore.

Question 69

Viruses consist of a:

A)histone molecule associated with a circular chromosome.
B)nucleic acid surrounded by a protein coat.
C)DNA genome associated with small RNAs.
D)small prokaryotic cell associated with plasmids.
E)telocentric chromosome surrounded by cohesin.

Question 70

Compare the haploid portion of the life cycle of a higher animal with the haploid portion of the life cycle of a higher plant (angiosperm).