Florida National University Biology Cells Practice Exam

0.25 PointsA cell is dividing by binary fission. What can you conclude?

1. Mitosis has taken place without cytokinesis.
2. Homologous chromosomes have already paired.
3. The cell is prokaryotic.
4. The cyclin-Cdk complex is no longer phosphorylating enzymes.
5. The cell cycle is out of control.

0.25 PointsPlant hormones known as ____ stimulate mitosis.

1. growth factors
2. cohesins
3. cytokinins
4. scaffolding proteins
5. cyclins

0.25 PointsTo prevent disastrous consequences, the eukaryotic cell cycle is controlled by:

1. replication.
2. a very detailed, rigid genetic program.
3. the mitochondria.
4. a series of cell cycle checkpoints.
5. environmental signals.

0.25 PointsWhat would happen if meiosis did not occur in sexually reproducing organisms?

1. The growth of the zygote would be halted.
2. The gametes would remain haploid.
3. The eggs would be haploid, but the sperm would be diploid.
4. Mitosis would be sufficient to produce haploid gametes.
5. The chromosome number would double in each generation.

0.25 PointsA bacterial chromosome consists of a:

1. linear DNA molecule many times larger than the cell.
2. circular DNA molecule smaller than the cell.
3. linear or circular DNA molecule smaller than the cell.
4. linear DNA molecule smaller than the cell.
5. circular DNA molecule many times larger than the cell.

0.25 PointsChromosomes are duplicated during the ____ of the cell cycle.

1. prophase
2. S phase
3. metaphase
4. G2 phase
5. G1 phase

0.25 PointsWhen is a cell in metaphase?

1. The chromosome are separated into distinct groups at opposite poles of the cell.
2. Cytokinesis is occurring.
3. The chromosomes are aligned at the midplane of the cell.
4. The chromosomes are visible as threadlike structures.
5. The nuclear envelope is clearly visible.

0.25 PointsEukaryotic chromosomes consist of:

1. linear DNA molecules complexed with positively charged histone proteins.
2. circular DNA molecules complexed with negatively charged histone proteins.
3. circular DNA molecules folded to fit inside a bacterial cell.
4. linear DNA molecules complexed with negatively charged histone proteins.
5. circular DNA molecules complexed with positively charged nonhistone proteins.

0.25 PointsDuring which stage of meiosis do the sister chromatids separate?

1. anaphase I
2. metaphase II
3. anaphase II
4. metaphase I
5. telophase II

0.25 PointsChromosomes are duplicated during the ____ of the cell cycle.

1. G2 phase
2. metaphase
3. prophase
4. S phase
5. G1 phase

0.25 PointsA cell is dividing by binary fission. What can you conclude?

1. The cell is prokaryotic.
2. The cyclin-Cdk complex is no longer phosphorylating enzymes.
3. Mitosis has taken place without cytokinesis.
4. The cell cycle is out of control.
5. Homologous chromosomes have already paired.

0.25 PointsIn a human cell at prophase I, there are ____ tetrads.

1. 23
2. 4
3. 2
4. 92
5. 46

0.25 PointsA cell in the G2 phase:

1. has visibly distinct chromosomes.
2. is in mitosis.
3. has twice the amount of DNA present in a telophase nucleus.
4. is in cytokinesis.
5. lacks a visible nuclear membrane.

0.25 PointsA cell in the G2 phase:

1. is in mitosis.
2. lacks a visible nuclear membrane.
3. is in cytokinesis.
4. has twice the amount of DNA present in a telophase nucleus.
5. has visibly distinct chromosomes.

0.25 Points____ organized on chromosomes carry the information that controls the functions of the cell.

1. Nucleosomes
2. Proteins
3. Asters
4. Histones
5. Genes

0.25 PointsA nucleosome consists of DNA wrapped around scaffolding proteins.__________________

1. True
2. False

0.25 PointsGametophyte plants produce gametes using:

1. fertilization.
2. meiosis.
3. sporogenesis.
4. polyploidy.
5. mitosis.

0.25 Points____ organized on chromosomes carry the information that controls the functions of the cell.

1. Nucleosomes
2. Proteins
3. Histones
4. Asters
5. Genes

0.25 PointsIn fungi and protists, gametes produced by ____ of haploid cells fuse to form a ____ zygote, which then undergoes ____ to restore the haploid chromosome number.

1. meiosis, diploid, mitosis
2. mitosis, haploid, meiosis
3. meiosis, haploid, mitosis
4. mitosis, diploid, mitosis
5. mitosis, diploid, meiosis

0.25 PointsHomologous chromosomes can be identified and/or characterized by:

1. paternal chromosomes only.
2. maternal chromosomes only.
3. their similar and characteristic staining patterns.
4. the different centromere positions in the maternal vs. paternal chromosomes.
5. those chromosomes that do not have partners.

0.25 PointsWhich event occurs in prophase II?

1. formation of the cleavage furrow
2. disappearance of the spindle
3. condensation of the chromatin into chromosomes
4. formation of the chiasmata
5. crossing over occurs.

0.25 PointsCytokinesis in animal cells involves contraction of a ring of ____ microfilaments.

1. cyclin plus myosin
2. tubulin plus actin
3. cohesin plus actin
4. actin plus myosin
5. cyclin plus actin

0.25 PointsEukaryotic chromosomes are composed of:

1. proteins only.
2. DNA only.
3. circular chromatin.
4. karyotypes.
5. chromatin.

0.25 PointsWhat is the function of kinetochores?

1. Kinetochores attach to microtubules during mitosis.
2. Kinetochores are involved in cytokinesis.
3. Kinetochores regulate the length of the cell cycle.
4. Kinetochores are the site of DNA synthesis.
5. Kinetochores anchor spindle fibers to the centrioles.

0.25 PointsHomologous chromosomes undergo synapsis during:

1. anaphase II.
2. prophase I.
3. telophase II.
4. prophase II.
5. anaphase I.

0.25 PointsAn animal with a diploid number of 36 chromosomes will have ____ chromosomes in its gametes and ____ chromosomes in its somatic cells.

1. 36; 18
2. 36; 36
3. 18; 18
4. 36; 72
5. 18; 36

0.25 PointsIn unwound chromatin, nucleosomes are organized into large coiled loops held together by:

1. scaffolding proteins.
2. histones.
3. centromeres.
4. kinetochore proteins.
5. condensins.

0.25 PointsIn a prometaphase cell, the:

1. spindle fibers pull chromosomes to opposite sides of the cell.
2. duplicated chromosomes become visible with the light microscope.
3. nucleolus disappears.
4. nuclear envelope is visible with the light microscope.
5. mitotic spindle is beginning to assemble.

0.25 Points____ contain identical DNA sequences and are held together by ____ during mitosis.

1. Sister chromatids; spindle fibers
2. Sister chromatids; cohesin proteins
3. Daughter chromosomes; hydrogen bonding
4. Daughter chromosomes; ionic bonding
5. Sister chromosomes; histone proteins

0.25 PointsWhich of the following is produced by meiosis?

1. diploid cells
2. somatic cells
3. zygotes
4. polyploid cells
5. animal gametes

0.25 Points____ contain identical DNA sequences and are held together by ____ during mitosis.

1. Daughter chromosomes; hydrogen bonding
2. Sister chromatids; cohesin proteins
3. Sister chromatids; spindle fibers
4. Daughter chromosomes; ionic bonding
5. Sister chromosomes; histone proteins

0.25 PointsThe ____ is responsible for the separation of the chromosomes during the ____ of mitosis.

1. kinetochore; prophase
2. cell wall; anaphase
3. centromere; telophase
4. mitotic spindle; interphase
5. mitotic spindle; anaphase

0.25 PointsOnce nerve cells become mature, they do not typically undergo cell division. Based on your knowledge of the cell cycle, you might predict that mature nerve cells become arrested in the ____ of the cell cycle.

1. G0 phase
2. S phase
3. G1 phase
4. G2 phase
5. prophase

0.25 PointsA pair of centrioles is found at the center of the microtubule-organizing center in plant cells.__________________

1. True
2. False

0.25 PointsOnce nerve cells become mature, they do not typically undergo cell division. Based on your knowledge of the cell cycle, you might predict that mature nerve cells become arrested in the ____ of the cell cycle.

1. G1 phase
2. S phase
3. G2 phase
4. G0 phase
5. prophase

0.25 PointsA bacterial chromosome consists of a:

1. linear DNA molecule smaller than the cell.
2. linear DNA molecule many times larger than the cell.
3. circular DNA molecule smaller than the cell.
4. circular DNA molecule many times larger than the cell.
5. linear or circular DNA molecule smaller than the cell.

0.25 PointsTo control the cell cycle:

1. M-Cdk inhibits mitosis.
2. cyclins fluctuate during the cell cycle.
3. the activity of Cdks stays the same throughout the cell cycle.
4. the anaphase-promoting complex stimulates DNA replication.
5. Cdks are active only when they are released from cyclins.

0.25 PointsWhat evolutionary advantage is provided by sexual reproduction?

1. production of genetically identical offspring
2. making polyploidy possible
3. making clones
4. removal of all genetic mutations
5. increased genetic diversity

0.25 PointsAn animal with a diploid number of 36 chromosomes will have ____ chromosomes in its gametes and ____ chromosomes in its somatic cells.

1. 36; 72
2. 36; 36
3. 18; 18
4. 36; 18
5. 18; 36

0.25 PointsNucleosomes are best described as:

1. prokaryotic DNA associated with histone proteins.
2. eukaryotic DNA associated with scaffolding proteins.
3. prokaryotic DNA associated with nonhistone proteins.
4. eukaryotic DNA associated with histone proteins.
5. eukaryotic DNA associated with nonhistone proteins.