chapter 10 bio
Plant cell cytokinesis
- cell plate - fusion of vesicles - lacks asters
If the gene encoding one of the proteins that forms cohesin were mutated such that cohesin could not perform its normal function, what would be the consequence?
-Chromosomes would not be able to condense. -Chromosomes would not be able to properly align at the metaphase plate. -The separation of sister chromatids would not likely occur specifically during anaphase A. -The nuclear envelope would not be able to reform.
A new small molecule drug inhibits the function of the APC/C. If this drug were applied to cells undergoing the cell cycle, what do you think would be the result?
-Securin would not be destroyed in these cells. -These cells would not be able to undergo Anaphase A. -These cells would not be able to degrade mitotic cyclins. -These cells would not be able to exit mitosis.
Estimates are that p53 is mutated in 50% of all human cancers. If the gene that encodes p53 is mutated such that p53 is non-functional, what processes would be affected?
-The ability to halt the cell cycle in response to DNA damage. -The ability to repair DNA damage. -The ability to stimulate cell death processes if the cell is irreparably damaged.
If a gene encoding one of the proteins that is part of the condensin complex was mutated such that condensin could not bind properly with DNA, what would be the result?
-There is likely a mutation in a gene that encodes an SMC protein. -There may be chromosome breakages that occur during mitosis, because compaction of the chromosome cannot properly occur.
In a human somatic cell (normal body cell) that is in G1, what would be true about chromosome number and structure?
-These cells would be considered diploid (2n). -These cells would contain homologous chromosomes.
In a human somatic cell (normal body cell) that is in G2, what would be true about chromosome number and structure?
-These cells would be considered diploid (2n). -These cells would contain homologous chromosomes. -These cells would contain sister chromatids.
sister chromatids
-attached to each other by cohesion -replica of single chromosome -formed during interphase -separated during mitosis
cytokinesis
-cells divide -cleavage furrow and plate forms
anaphase
-centrosomes split and move apart -sister chromatids separate
metaphase
-chromosomes align at equator -the spindle checkpoint arrests cells
prophase
-chromosomes become visible -spindles first form
Animal cell cytokinesis
-cleavage furrow -constricting belt of actin -centrioles separate
homologous chromosomes
-maternal and paternal pairs -in humans their are 23 pairs of these -numbered in kyrotype
telophase
-nucleus reformation -chromosomes at poles
interphase
-replicating DNA -cell prepares for division
The cells of most eukaryotes have between 10 and which number of chromosomes?
50
How many generations does it take for a single bacterial cell to become 256?
8
During anaphase ______, sister chromatids are pulled towards opposite poles as their kinetochore microtubules, which are attached to the poles, are shortened.
A
Mutations in the protein retinoblastoma (Rb) are often associated with cancer in the eye. What mutation might lead to cancer?
A mutation that prevents Rb from interacting with myc
During anaphase, two forms of movement take place simultaneously and as a result sister chromatids are pulled towards opposite poles of the cell. The two forms of movement are commonly referred to as anaphase _____ and anaphase ____.
A, B
Passage through checkpoints is controlled by _____ enzymes.
Cdk
What usually occurs during the G1 phase?
Cells are growing
When DNA replicates the sister chromatids are held together at their centromeres by which of the following complex of proteins?
Cohesins
The generation time for the five bacterial species mentioned in the animation are shown below. Which of these bacteria would be the best organism for scientists to use to study genetics, and why?
Escherichia coli, because many generations can be examined in a short period of time.
The _______ phase is considered a resting phase in the cell cycle.
G0
In a cell's life, cell growth occurs primarily during what phase?
G1
The _____ checkpoint is the primary point of the cell cycle that is influenced by external signals.
G1/S
Condensation of chromosomes is initiated in the ______ phase of interphase and continues until the end of prophase.
G2
During interphase, what is the name of the phase that occurs after the replication of DNA and before the start of mitosis?
G2
Which of the following phases occurs after the replication of DNA and before the start of mitosis?
G2
The _____ checkpoint assesses whether DNA is damaged, and also whether DNA replication has completed.
G2/M
Cell division in bacterial and eukaryotic cells produces which of the following?
Genetically identical cells
While preparing to divide, the cell grows and copies its chromosomes during which of the following stage?
Interphase
How does myc become active?
It dissociated from Rb.
The centromere serves as an attachment site for a group of proteins that form a disklike structure called which of the following?
Kinetochore
Which of the following is the key event in anaphase?
Removal of cohesin proteins from the centromeres of sister chromatids
Which type of microtubules attach to and separate the chromosomes during cell division?
The kinetochore microtubules
In streptococci, why is new cell wall only produced in certain regions of the daughter cells?
These bacteria possess cell wall from the parent, and only need to produce new cell wall in certain regions.
The growth factors illustrated in this system are positive regulatory growth factors. Why are they considered 'positive' growth factors.
They increase the rate of cell proliferation.
At the beginning of which of the following phases do the centromeres of sister chromatids split apart allowing sister chromatids separate from each other?
anaphase
During the ____ of mitosis, the centromeres of sister chromatids split apart allowing sister chromatids to move away from each other.
anaphase
which of the following is the shortest stage of mitosis?
anaphase
Which of the following cell types have centrioles?
animal
What is a sequence of growth, replication, and division that produces new eukaryotic cells called?
cell cycle
Growth factor receptors are typically found in the
cell membrane
The kinetochore microtubules are attached to kinetochores, which are bound to the ________, a point of constriction on the chromosome containing repeated DNA sequences.
centromere
Centromeres occur at a specific location along a:
chromosome
Which of the following events do NOT occur in prophase of mitosis?
chromosomes are replicated
The key event in anaphase is the removal of ______ proteins from the centromeres of sister chromatids.
cohesin
During G2, chromosomes begin to undergo ______.
condensation
The structure that divides the bacterial cell in two is termed the
cross septum
In multicellular eukaryotic organisms, the production of new cells follows a highly regulated sequence of growth, DNA replication, and division. This sequence is referred to as the cell ______ , which consists of the G1, S, G2, and M phases.
cycle
If the protein retinoblastoma is ________, it can bind to and ________ the Myc protein.
dephosphorylated; inactivate
During telophase, chromosomes uncoil to allow for gene _____.
expression
True or false: A centromere is located at a random location along the length of a chromosome.
false
True or false: In a typical mammalian adult cell, the M phase takes up a large fraction of the entire cell cycle.
false
Cell division in bacterial cells and eukaryotic cells involves the replication and segregation of ______ information and the division of contents within the cell.
genetic
During G1, cells undergo the major portion of their ________.
growth
The ______ is a dislike protein structure found at the point of constriction on the chromosome.
kinetochore
The centromere contains repeated DNA sequences that can bind specific proteins. These proteins form the _______ , which is shaped like a disk.
kinetochore
During prometaphase, sister chromatids attach to the spindle by their ______ , which are attached to the centromere region of each sister chromatid.
kinetochores
During prometaphase, which protein complex on each sister chromatid attaches to the spindle?
kinetochores
Sister chromatids are pulled towards opposite poles of the cell by microtubules attached to their ______.
kinetochores
During telophase, the nuclear envelope re-forms to produce two separate ______.
nuclei
In bacterial cells, the replication of DNA begins at a specific site called _____ the of replication, and proceeds in both directions around the circular DNA until a specific _____ site is reached.
origin, temrmination
Condensation of chromosomes continues throughout which of the following phases?
prophase
During telophase, the changes made to the cell during _____ are reversed.
prophase
Which is the first stage of mitosis?
prophase
Chromosomes are composed of chromatin which is a complex of DNA and which of the following?
protein
During cell division in both bacterial cells and eukaryotic cells, genetic information is ______ and segregated and the contents of the cell are divided between the daughter cells.
replicated
During the ______ phase of the cell cycle, the chromosomes are replicated.
s
Replication of each chromosome and its centromere takes place during the _____ phase to produce two complete DNA molecules.
s
Replication of each chromosome and its centromere takes place during the ______ phase to produce two complete DNA molecules.
s
During which phase of the cell cycle are the chromosomes replicated?
s phase
After S phase ______ appear to share a common centromere.
sister chromatids
During DNA replication the chromosomes contract and the identical halves are called _______ _______.
sister chromatids
The ______ checkpoint ensures that all of the chromosomes are attached to microtubule
spindle
Two centriole pairs establish a bridge of microtubules which form the _____ ______ during prophase.
spindle apparatus
During the stage of mitosis known as ______ , gene expression resumes, as chromosomes uncoil.
telophase
What phase of mitosis is characterized by the reformation of the nuclear envelope and the production of two separate nuclei?
telophase
When is the spindle apparatus is broken down?
telophase
______ is the final phase of mitosis.
telophase
_______ can be viewed as the stage of mitosis during which the changes made to the cell during prophase are reversed.
telophase
Which of the following statements about microtubules during anaphase is TRUE?
those attached to chromosomes shorten, while those that are unattached elongate
True or false: Bacterial cell division produces genetically identical daughter cells.
true
During interphase, all eukaryotic cells synthesize large amounts of ______.
tubulin
Chromatin is a complex with ~40% DNA and which of the following?
~60% Protein
Typically, a dividing mammalian cell completes its cell cycle in about how many hours?
24 hours
The human cell contains a total of how many chromosomes?
46
the steps in binary fission
1)the bacterial DNA replicates 2)the cell elongates and the DNA partitioned such that the origins are at the 1/4 and 3/4 positions in the cell 3)seperation begins 4)the cell pinches in two, framing two daughter cells.
The generation time of Mycobacterium tuberculosis is
12 hours
Cell division in bacterial and eukaryotic cells produces genetically _____ cells.
identical
During bacterial cell division two, genetically _______ ________ ________ , daughter cells are produced.
identical (blank 1 only)
During _________ , which includes the G1, S and G2 phases of the cell cycle, the cell grows and chromosomes replicate in preparation for cell division.
interphase
Docetaxel is a drug that is used in the treatment of cancer. It interferes with cell division by inhibiting microtubule depolymerization. Specifically what would be the greatest impact of this drug on mitosis?
it will prevent sister chromatids from separating during anaphase.
During ____ the chromosomes are aligned midway between the spindle poles.
metaphase
The pairs of sister chromatids align themselves in a single row along a plane half-way between the poles during which of the following phases of mitosis?
metaphase
The term ______ is from the Greek "mitos", meaning thread.
mitosis
During the five phases of _________ , the replicated genetic material is partitioned into ______ new nuclei.
mitosis, 2
