Chapter 11 Bio
Recall the experiments of Rous and colleagues. If he has found that filtered cancer cell extract could not cause cancer when injected into healthy animals, what could he have deduced ?
1. Cancer may be caused by bacteria 2. An intact cancer cell is necessary to cause cancer 3. A large protein may cause cancer
What is a characteristic of meiotic cell division?
1. Cell division results in the production of gametes 2. Cell division results in the formation of four daughter cells 3. Cell division requires two rounds of nuclear division
What is not true regarding viruses?
1. Contain multiple genes, each of them an oncogene 2. Only contain DNA, which is capable of inserting itself into a host cell's genome 3. Are the root cause of most-if not all-cancers 4. Human cancers have not been associated with viruses
What is true regarding the cell cycle?
1. It has three cell cycle checkpoints 2. It is regulated by the Cyclones and CDKs 3. Different levels of cyclins are observed at different cell cycle stages 4. It can be "paused" by the action of p53
What is true regarding cancer- according to Hanahan and Weinberg- ?
1. Secrete factors that promote angiogenesis, or blood vessel formation 2. Metastasize and travel throughout the body 3. Growth factors are required 4. Resist cell-death signals
The prokaryotic protein FtsZ is evolutionarily related to eukaryotic tubulin. What does this mean?
1. The genes sequence for FtsZ is similar to tubulin 2. The amino acid sequence for FtsZ is similar to tubulin 3. The overall protein structure of FtsZ is similar to tubulin
Asexual reproduction occurs in:
1. Unicellular eukaryotes 2. Skin cells 3. Plant dermal cells
How many chromosome pairs are there in the human genome?
23
At the start of mitosis, how many centromeres are present in a human cell ?
46
What is a cyclin?
A protein that activates kinases and whose levels change with the cell cycle
The division of the cell's cytoplasm in a eukaryotic cell is know as:
Cytokinesis
Imagine that 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 ( lasting approximately 12 hours) and is characterized by an increase in the DNA content of cells. This second stage is most likely:
Interphase
What is true regarding the S cyclin-CDK complex?
It assures that DNA is not relocated multiple times
What is the role of the protein FtsZ?
It forms a ring at the site of constriction
What is not true regarding the protein CDK?
The levels of CDK change with the cell cycle
Evidence exists (especially in dinoflagellates) that mitosis actually 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
Some types of leukemia are the result of constitutively active (I.e., "always on") growth factor receptors.
True
The alignment of chromosomes at metaphase of meiosis II is most similar to the alignment of chromosomes during metaphase of mitosis.
True
What is the function of histone proteins?
To organize DNA in eukaryotic chromosomes
In what phase of mitosis do microtubules shorten?
Anaphase
In which phase of mitosis do sister chromatids separate?
Anaphase
At what step in meiosis do the daughter cells become haploid?
Anaphase I
When do sister chromatids separate in meiosis?
Anaphase II
The process of cell division in a prokaryotic cell is called:
Binary fission
Predict what would happen if crossing over occurred as part of mitosis.
Daughter cells would not be genetically identical, and they could contain two copies of the same allele
A zygote is:
Diploid
All cancers are caused by viruses.
False
A phragmoplast functions to:
Form a new cell wall
A cell that is not actively dividing is in what phase of the cell cycle?
G0
Another name for non-sister chromatids is:
Homologous chromosomes
What happens to CDK in the absence of cyclin?
It is inactive
Why would a compound that interferes with bacterial cell wall synthesis be useful for the treatment of an infection ?
It would limit the spread of infection
In which phase of mitosis do chromosomes line up at the middle of the cell?
Metaphase
How must spindle microtubule attach to chromosomes during anaphase of meiosis I?
Microtubule simply attach to one kinetochore per homologous pair
The division of genetic material in a eukaryotic cell is called:
Mitosis
What would happen if crossing over occurred between sister chromatids ?
Nothing, sister chromatids are identical
A women has her genome sequenced and finds that she carries a mutation in p53. Will she develop cancer ?
Possible-this mutation may predispose her to developing certain types of cancer
In what phase of mitosis do chromosomes condense ?
Prophase
In what phase of mitosis does the meiotic spindle form?
Prophase
Crossing over occurs during which phase in meiosis?
Prophase I
What type of gene is c-src (cellular-src)?
Proto-oncogene
What is not a step in the process of binary fission?
Rearrangement of the microtubule cytoskeleton
Replication of DNA in a eukaryote occurs during which phase of the cell cycle ?
S phase
In what phase of mitosis does the nuclear envelope reform?
Telophase
Synopsis is best described as:
The alignment of homologous chromosomes in prophase I.
Mitotic cell division is considered asexual because:
The daughter cells receive DNA from one parent cell, and the daughter cells are genetically identical
What is the function of the centromere?
To attach the sister chromatids to each other
How do new cyclin proteins appear in the cytoplasm?
They are made through protein synthesis
