front 1 A bacterial chromosome consists of:
- a linear DNA
molecule many times larger than the cell.
- a circular DNA
molecule many times larger than the cell.
- a circular DNA
molecule smaller than the cell.
- a linear DNA molecule
smaller than the cell.
- a linear or circular DNA molecule
smaller than the cell.
| back 1 a circular DNA molecule many times
larger than the cell. |
front 2
Eukaryotic chromosomes consist of:
- circular DNA
molecules complexed with positively charged nonhistone
proteins.
- circular DNA molecules complexed with
negatively charged histone proteins.
- linear DNA molecules
complexed with positively charged histone proteins.
- linear
DNA molecules complexed with negatively charged histone proteins.
circular DNA molecules. | back 2
linear DNA molecules complexed with
positively charged histone proteins. |
front 3
Nucleosomes are best
described as:
- eukaryotic
DNA associated with histone proteins.
- prokaryotic DNA
associated with nonhistone proteins.
- eukaryotic DNA
associated with nonhistone proteins.
- prokaryotic DNA
associated with histone proteins.
- eukaryotic DNA associated
with scaffolding proteins.
| back 3
eukaryotic DNA associated with histone proteins. |
front 4 What is the function of nucleosomes?
- To prevent
DNA strands from tangling.
- To help DNA replicate.
- To make RNA synthesis possible.
- To prevent RNA from
tangling with DNA during transcription.
- To prevent
histones from tangling.
| back 4 To prevent DNA strands from tangling. |
front 5
Nucleosomes are organized into large coiled loops held
together by:
- histones.
- centromeres.
- kinetochore
proteins.
- scaffolding proteins.
- condensins.
| |
front 6 The cell cycle of a typical somatic cell
consists of __________ and M phase.
- interphase
- meiosis I
- crossing-over
- meiosis II
- mitosis
| |
front 7
The M phase of the cell cycle
involves two main processes:
- mitosis and
cytokinesis.
- meiosis I and meiosis II.
- homologous
pairing and crossing-over.
- interphase and mitosis.
- mitosis and meiosis.
| |
front 8 Once nerve cells become mature, they don't usually undergo cell
division. Based on your knowledge of the cell cycle, you would predict
that mature nerve cells become arrested in the
__________ of the cell cycle.
- G0 phase
- S phase
- prophase
- G1 phase
- G2 phase
| |
front 9
Chromosomes are duplicated during __________ of the
cell cycle.
- G1 phase
- G2 phase
- S
phase
- metaphase
- prophase
| |
front 10 Which of the following represents the
overall sequence of events during mitosis?
- prophase -
prometaphase - metaphase - anaphase -telophase
- interphase
- prometaphase - metaphase - anaphase - telophase
- anaphase
- telophase - metaphase - prophase - interphase
- interphase
- prophase - anaphase - metaphase - prometaphase
- metaphase
- telophase - prometaphase - anaphase - prophase
| back 10 -
prophase - prometaphase -
metaphase - anaphase -telophase
|
front 11
If a cell is in G2:
- it has twice
the amount of DNA present in a telophase nucleus.
- it has
visibly distinct chromosomes.
- it lacks a visible nuclear
membrane.
- it is in mitosis.
- it is in
cytokinesis.
| back 11 it has twice the amount of DNA present in a
telophase nucleus. |
front 12
During prophase, __________ is(are)
compacted into visible chromosomes.
- chromatin
- centrioles
- centromeres
- kinetochores
- colchicine
| |
front 13 The __________ is responsible for the separation of
the chromosomes during __________ of mitosis.
- cell wall;
anaphase
- flagellum; metaphase
- mitotic spindle;
anaphase
- kinetochore; prophase
- centromere;
telophase
| back 13
mitotic spindle; anaphase |
front 14 __________ contain identical DNA sequences and are
held together by __________ during mitosis.
- Daughter
chromosomes; hydrogen bonding
- Daughter chromosomes; ionic
bonding
- Sister chromatids; spindle fibers
- Sister
chromosomes; histone proteins
- Sister chromatids;
centromeres
| back 14
Sister chromatids; centromeres |
front 15 The mitotic spindle is made of:
-
collagen.
-
condensin.
-
histones.
-
keratin.
-
microtubules.
| |
front 16 Which of the following represents the
overall sequence of events during mitosis?
- prophase - prometaphase
- metaphase - anaphase -telophase
- interphase - prometaphase
- metaphase - anaphase - telophase
- anaphase - telophase -
metaphase - prophase - interphase
- interphase - prophase -
anaphase - metaphase - prometaphase
- metaphase - telophase -
prometaphase - anaphase - prophase
| back 16 -
prophase - prometaphase -
metaphase - anaphase
-telophase
|
front 17
All of the following events occur during
prometaphase EXCEPT:
-
the nuclear envelope breaks down.
-
the nucleoli disappear.
-
the mitotic spindle is completely assembled.
-
the spindle fibers "capture" chromosomes.
-
the duplicated chromosomes become visible with the light
microscope.
| back 17 the duplicated chromosomes become visible with the
light microscope. |
front 18
A cell is in metaphase if:
-
the chromosomes are visible as threadlike structures.
-
the nuclear envelope is clearly visible.
-
the chromosomes are aligned at the midplane of the cell.
-
the chromosome are separated into distinct groups at opposite
poles of the cell.
-
cytokinesis is occurring.
| back 18 the chromosomes are aligned at the midplane of the cell. |
front 19
Duplicated centrioles move to opposite poles of a
dividing __________ cell during __________ of the
cell cycle.
-
plant; metaphase
-
plant; anaphase
-
prokaryotic; metaphase
-
animal; interphase
-
animal; prophase
| |
front 20 The chromosome makeup of an individual organism is
called a:
- kinetochore.
- chromosome plot.
- centromere.
- karyotype.
- centriole.
| |
front 21
Chromosomes are condensed to their greatest
extent during __________ of mitosis.
- metaphase
- prophase
- telophase
- interphase
- anaphase
| |
front 22
Cytokinesis in animal cells involves contraction of a
ring of __________ microfilaments.
- tubulin plus
actin
- actin plus myosin
- cyclin plus myosin
- keratin plus actin
- cyclin plus actin
| |
front 23
Cytokinesis in plant cells occurs via the
formation of a(n):
- aster.
- mitotic spindle.
- Golgi complex.
- cell
wall.
- cell plate.
| |
front 24 If a cell is dividing by binary fission then you
know that:
-
mitosis has taken place without cytokinesis.
-
homologous chromosomes have already paired.
-
the cyclin-Cdk complex is no longer phosphorylating enzymes.
-
the cell cycle is out of control.
-
the cell is prokaryotic.
| |
front 25 To prevent disastrous consequences, the
eukaryotic cell cycle is controlled by:
- the
mitochondria.
- helper viruses.
- environmental
signals.
- a very detailed, rigid genetic program.
- a
series of cell cycle checkpoints.
| back 25 a series of cell cycle checkpoints. |
front 26 Which of the following statements concerning
the cell cycle is FALSE?
-
The activity of Cdks increases and decreases during the cell
cycle.
-
Cyclins fluctuate during the cell cycle.
-
are active only when they bind to cyclins.
-
The anaphase-promoting complex stimulates the separation of
sister chromatids.
-
M-Cdk inhibits mitosis.
| |
front 27 The correct number of chromosomes is
maintained during sexual reproduction by:
- a process by which
one half of the chromosomes in gametes are removed.
- chromosome doubling in the newly formed zygote.
- meiosis, which reduces the chromosome number by half.
- mitosis, which maintains the original chromosome number.
- replication of chromosomes twice during meiosis.
| back 27
meiosis, which reduces the
chromosome number by half. |
front 28
Animal cells are stimulated to divide by mitosis by:
- colchicines.
- magnetic fields.
- mating.
- growth factors.
- nutrients.
| |
front 29
If meiosis did not occur in sexually reproducing
organisms, then:
- growth of the zygote
would be halted.
- mitosis would be sufficient.
- gametes would remain haploid.
- chromosome number would
double in each generation.
- eggs would be haploid, but sperm
would be diploid.
| back 29
chromosome number would double in
each generation. |
front 30 What evolutionary advantage is provided by
sexual reproduction?
- increased genetic
diversity
- making clones
- making diploidy
possible
- making polyploidy possible
- being able to
work with chromosomes
| back 30
increased genetic diversity |
front 31
Plant hormones known as __________ stimulate mitosis.
- gametophytes
- kinesin and dynein
- cytokinins
- colchicines
- kinetochores
| |
front 32
Homologous chromosomes undergo synapsis during:
-
anaphase I.
-
prophase I.
-
anaphase II.
-
telophase II.
-
prophase II.
| |
front 33 A maternal homologue and a paternal
homologue synapse to form:
- a tetrad.
- a
parental pair.
- a paternal pair.
- sister
chromatids.
- a maternal pair.
| |
front 34
During which phase does crossing-over occur?
- interphase
- prophase I
- metaphase I
- prophase II
- metaphase II
| |
front 35 A zygote contains the __________ number of chromosomes.
- haploid
- diploid
- polyploid
- spermatogenesis
- none
of these
| |
front 36 In a human cell at prophase I, there are __________ tetrads.
- 92
- 46
- 23
- 2
- 4
| |
front 37 An animal with a diploid number of 36 chromosomes
will have __________ chromosomes in its
gametes and __________ chromosomes
in its somatic cells.
- 18; 18
- 18;
36
- 36; 18
- 36; 36
- 36; 72
| |
front 38 During prophase I, each chiasma represents:
- the remnants of the
nuclear membrane.
- the remnant of the nucleolus.
- a
newly formed haploid gamete.
- a site of crossing-over.
- the site where sister chromatids are connected.
| |
front 39 During which of the following stages of
meiosis do the sister chromatids separate?
- metaphase I
- anaphase I
- metaphase II
- anaphase II
- telophase II
| |
front 40 Which of the following represents the
overall sequence of events during mitosis?
- prophase - prometaphase
- metaphase - anaphase -telophase
- interphase - prometaphase
- metaphase - anaphase - telophase
- anaphase - telophase -
metaphase - prophase - interphase
- interphase - prophase -
anaphase - metaphase - prometaphase
- metaphase - telophase -
prometaphase - anaphase - prophase
| back 40 -
prophase - prometaphase -
metaphase - anaphase
-telophase
|
front 41 The sources of genetic variation during meiosis are:
- crossing-over and the
random assortment of maternal and paternal chromosomes.
- crossing-over and random pairing of tetrads.
- random
pairing of tetrads and mutations.
- polyploidy and random
pairing of tetrads.
- random pairing of tetrads and random
assortment of maternal and paternal chromosomes.
| back 41
crossing-over and the random assortment
of maternal and paternal chromosomes. |
front 42 Which of the following events does not occur
during meiosis I?
- DNA exchange
- pairing of homologous chromosomes
- separation of sister
chromatids
- separation of homologous chromosomes
- crossing-over between homologous chromosomes
| back 42
separation of sister chromatids |
front 43
Figure 10-1 Use the figure to answer the
corresponding question(s). Refer to Figure 10-1. Which of the
following combinations of letters accurately
represents two sister chromatids?
- A and B
- A and
C
- A and D
- A and E
- B and F
| |
front 44
Figure 10-1 Use the figure to answer the
corresponding question(s). Refer to Figure 10-1. Which of the
following combinations of letters accurately
represents two homologous chromatids?
- A and B
- A and
C
- A and D
- B and F
- D and E
| |
front 45 The formation of female gametes is termed:
- oogenesis.
- macrogenesis.
- spermatogenesis.
- ovogenesis.
- microgenesis.
| |
front 46 Which of the following are
NOT produced by meiosis?
- polar bodies
- animal eggs
- animal sperm
- plant spores
- zygotes
| |
front 47
Figure 10-2 Use the figure to answer the
corresponding question(s). Refer to Figure 10-2. The
chromosome complement of item 6 in the life cycle is:
- twenty.
- haploid.
- diploid.
- forty-eight.
- four.
| |
front 48
Figure 10-2 Use the figure to answer the
corresponding question(s). Refer to Figure 10-2. The process
occurring at arrow 3 in the associated figure is:
- fertilization.
- G1.
- meiosis.
- mitosis.
- fusion.
| |
front 49
Gametophyte plants produce gametes using:
- mitosis.
- meiosis.
- fertilization.
- polyploidy.
- sporogenesis.
| |
front 50
Sporophyte plants produce spores using:
- mitosis.
- meiosis.
- fertilization.
- macrogenesis.
- microgenesis.
| |