Biology I Chapter 11

A zygote is: monoploid. haploid. polyploid. diploid.

diploid

How many chromosome pairs are there in a normal human genome? 22 23 46 64

23

At the start of mitosis, how many sister chromatids are present in a human cell? 12 23 46 92

92

Asexual reproduction occurs in: unicellular eukaryotes. animal cells. plant cells. bacterial cells. All of these choices are correct.

All of these choices are correct.

The prokaryotic protein FtsZ is evolutionarily related to eukaryotic tubulin. What does this mean? The gene sequence for FtsZ is similar to tubulin. The amino acid sequence for FtsZ is similar to tubulin. The overall protein structure of FtsZ is similar to tubulin. The two proteins evolved from a common ancestral protein. All of these choices are correct.

All of these choices are correct.

Muscle cells in the mammalian heart are multinucleate, meaning that multiple nuclei are present in the cytoplasm of a large cell. Predict what is different about the cell cycle in a muscle cell. S phase happens twice. The G1 and G2 phases are extended. Cytokinesis does not occur. M phase is inhibited.

Cytokinesis does not occur.

Which of the following statements is true regarding binary fission? Proteins only anchor the original circular genome to the plasma membrane; the copy produced by DNA replication is free-floating. In binary fission, cell division is typically asymmetrical, with one daughter cell appearing much smaller than the other. Tubulin, rather than FtsZ, is responsible for cell division during binary fission. DNA replication during binary fission is a bidirectional process, occurring in opposite directions. None of the answer options is correct.

DNA replication during binary fission is a bidirectional process, occurring in opposite directions.

Which of the following is NOT a characteristic of meiotic cell division? Cell division results in the production of gametes. Cell division requires two rounds of nuclear division. Daughter cells are genetically identical. Cell division results in the formation of four daughter cells.

Daughter cells are genetically identical.

Why would a compound that interferes with bacterial cell wall synthesis be useful for treating a bacterial infection? It would prevent replication of DNA. It would prevent the cells from becoming larger. It would limit the spread of the infection through cell division. It would prevent replication of DNA, and it would limit the spread of the infection.

It would limit the spread of the infection through cell division.

What would happen if crossing over occurred between sister chromatids? Genetic diversity would decrease due to the loss of gene combinations. Genetic diversity would increase due to the addition of gene combinations. Gene rearrangement would lead to changes in gene expression. Nothing would happen because sister chromatids are genetically identical or nearly identical.

Nothing would happen because sister chromatids are genetically identical or nearly identical.

How must spindle microtubules attach to chromosomes during prometaphase of meiosis I? Spindle microtubules from one pole must attach to both kinetochores in a pair of sister chromatids. Microtubules attach at the centrosomes. Spindle microtubules from one pole attach to one kinetochore, and spindle microtubules from the other pole attach to the other kinetochore in a pair of sister chromatids, just like in mitosis. Microtubules attach to the chiasma. Microtubules attach using their minus (slow assembling) ends.

Spindle microtubules from one pole must attach to both kinetochores in a pair of sister chromatids.

What would happen to the daughter cells if the G2 phase of the parent cell is shortened? The cells would be larger than normal. The cells would be smaller than normal. The cells would not undergo cytokinesis. The cells would be missing chromosomes.

The cells would be smaller than normal.

Why are the X and Y chromosomes not considered homologous? They do not carry the same set of genes. They come from different parents. Mammalian males carry two very different chromosomes. They do not carry the same set of genes, and mammalian males carry two very different sex chromosomes.

They do not carry the same set of genes, and mammalian males carry two very different sex chromosomes.

Polar bodies are: produced by mitosis. functional gametes that are produced by mitosis. haploid cells. functional gametes that are produced by meiosis.

haploid cells

True or False. Evidence exists (especially in dinoflagellates) that mitosis evolved from binary fission. For example, in certain eukaryotic cells during mitosis, DNA is attached to the membrane of the nucleus (much like a circular chromosome of a bacterium is attached to the plasma membrane).

True

True or False. The alignment of chromosomes at metaphase of meiosis II is most similar to the alignment of chromosomes during metaphase of mitosis.

True

What protein forms the contractile ring during cytokinesis in animal cells? kinesin actin DNA polymerase dynein

actin

During what step in meiosis do the daughter cells become haploid? anaphase I metaphase II anaphase II prophase II

anaphase II

When do sister chromatids separate in meiosis? telophase I metaphase II anaphase II anaphase I

anaphase II

How does meiosis generate genetic diversity? synapsis crossing over random alignment at metaphase I both crossing over and random alignment at metaphase I

both crossing over and random alignment at metaphase I

What cellular process(es) is/are responsible for the increase in protein content associated with the gap phases of the cell cycle? both gene expression and protein synthesis glycolysis gene expression protein synthesis

both gene expression and protein synthesis

A human cell with a total of 23 chromosomes is: Please choose the correct answer from the following choices, and then select the submit answer button. polyploid. haploid. aneuploid. diploid.

haploid

A researcher is studying a population of cells with two major phases. The first phase is relatively short (it lasts approximately one hour), whereas the second stage is much longer (it lasts approximately 12 hours) and is characterized by an increase in the DNA content of cells. This second stage is most likely: G0. interphase. mitosis. cytokinesis.

interphase.

Homologous chromosomes separate from each other in: mitosis. meiosis I. meiosis II. They never separate from each other during any form of cell division.

meiosis I.

In which phase of mitosis do chromosomes line up at the middle of the cell? telophase metaphase anaphase prophase

metaphase

What cytoskeletal protein is important to the function of the sperm cells illustrated in Figure 11.13? Click to view full size. microfilaments intermediate filaments microtubules All of these choices are correct.

microtubules

In which phase of mitosis does the nuclear envelope reform? prophase anaphase metaphase telophase

telophase

Synapsis is best described as: the exchange of genetic information between sister chromatids. the alignment of non-sister chromatids at the metaphase plate. the exchange of genetic information between non-sister chromatids. the pairing of homologous chromosomes in prophase I.

the pairing of homologous chromosomes in prophase I.

What is the function of the centromere? to attach the DNA to the plasma membrane to attach the chromosome to the spindle to organize the microtubules to form a spindle to attach the sister chromatids to each other

to attach the sister chromatids to each other

What is the function of histone proteins? to package DNA in eukaryotic chromosomes to attach sister chromatids together to connect chromosomes to the mitotic spindle to organize the microtubules that make up the spindle

to package DNA in eukaryotic chromosomes