Chapter 11 Learning Curve
What would happen if a chromosome only connected to the mitotic spindle at one of its kinetochores?
-One of the daughter cells would have an extra copy of that chromosome. -The sister chromatids would not separate. -The chromosome would not line up properly at metaphase.
What is the role of the protein FtsZ?
It forms a ring at the site of constriction.
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.
What would happen to the daughter cells if the G2 phase of the parent cell is shortened?
The cells would be smaller than normal.
The prokaryotic protein FtsZ is evolutionarily related to eukaryotic tubulin. What does this mean? Please choose the correct answer from the following choices, and then select the submit answer button.
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.
Which of the following is not true regarding CDKs?
The levels of CDK change with the cell cycle.
How do new cyclin proteins appear in the cytoplasm?
They are made through protein synthesis.
Why are the X and Y chromosomes not considered homologous?
They do not carry the same set of genes, and mammalian males carry two very different sex chromosomes.
How do CDKs promote cell division?
They phosphorylate other proteins.
When do sister chromatids separate in meiosis?
anaphase II
The microtubules that form the mitotic spindle extend out from the centrosome. Where would you expect to find the plus (fast assembling) end of a spindle microtubule?
away from the centrosome, at the kinetochore
A phragmoplast functions to:
form a new cell wall
Another name for non-sister chromatids is:
homologous chromosomes
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:
interphase
A malignant cancer differs from a benign cancer in that:
malignant cancers invade surrounding tissue and benign cancers do not.
Which of the following is not a step in the process of binary fission?
rearrangement of the microtubule cytoskeleton
Asexual reproduction occurs in:
-unicellular eukaryotes. -animal cells. -plant cells. -bacterial cells.
How many chromosome pairs are there in a normal human genome?
23
At the start of mitosis, how many centromeres are present in a human cell?
46
At the start of mitosis, how many centromeres are present in a human cell? Please choose the correct answer from the following choices, and then select the submit answer button.
46
Why don't plant cells use a contractile ring to divide their daughter cells? Please choose the correct answer from the following choices, and then select the submit answer button.
A contractile ring can't "pinch" a cell wall.
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.
Cytokinesis does not occur.
Which of the following statements is true regarding binary fission?
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?
Daughter cells are genetically identical.
Predict what would happen if crossing over between homologous chromosomes occurred as part of mitosis.
Daughter cells would not be genetically identical, and they could contain two copies of the same allele.
Look carefully at the image of the human karyotype shown in Figure 11.3. What is the significance of the small differences between homologous chromosomes?
Each homologous chromosome in a pair is from a different parent.
Why would a compound that interferes with bacterial cell wall synthesis be useful for treating a bacterial infection?
It would limit the spread of the infection through cell division.
A woman has her genome sequenced and finds that she carries a mutation in p53. Will she develop cancer?
Possibly—this mutation may predispose her to developing certain types of cancer.
When in the cell cycle would you find sister chromatids?
S and G2
The process of cell division in a prokaryotic cell is called:
binary fission
A proto-oncogene is a "normal" gene that, if mutated, can become an oncogene and lead to a cell becoming cancerous.
true