Exam 2
During anaphase __, sister chromatids are pulled towards opposite poles as their kinetochore microtubules, which are attached to the poles, are shortened.
A
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
When does cytokinesis take place?
After mitosis
At the beginning of which phase does the centromeres of sister chromatids split apart allowing sister chromatids to separate from each other?
Anaphase
Which cell type has centrioles?
Animal
During anaphase __, microtubules slide past each other pulling the poles anchored to them, and the chromosomes attached to the poles, away from the center of the cell.
B
The __ enzymes control progression through the checkpoints in the cell cycle.
Cdk
Phosphorylation within the cell cycle is performed by enzymes called ___________________________.
Cdks
are cellular structures, typically found in animal cells, which are replicated during the G2 phase. They are positioned at the poles of the cell and participate in the movement of chromosomes during mitosis.
Centrioles
What organelles reabsorbs the components of the broken down nuclear membrane during mitotic division of the cell?
Endoplasmic reticulum
True or false: Cell division is complete at the end of mitosis.
False
Condensation of chromosomes is initiated in the ____________________________ phase of interphase and continues until the end of prophase.
G
Some cells remain in the __________________ phase permanently while others can proceed to the G1 phase when new cells are needed (e.g., during an injury).
G0
Some cells, such as muscle and nerve cells, remain permanently in which of the following phases of the cell cycle?
G0
The _________________ phase is considered a resting phase in the cell cycle.
G0
Which of the following phases in the cell cycle is considered a resting phase?
G0
Fruit flies have the shortest known animal cell cycle because they lack which of the following stages?
G1 and G2
Where is the start or restriction point for cell division?
G1/S checkpoint
Which of the following checkpoints is the phase during which growth factors affect the cell cycle and the phase that links cell division to cell growth and nutrition? a. G2/M checkpoint b. Cytokinesis c. G1/S checkpoint d. Spindle checkpoint
G1/S checkpoint
Passage through which checkpoint is a commitment to cell division?
G2/M checkpoint
Damage to DNA can halt division of the cell at which cycle(s)?
G2/M checkpoint G1/S checkpoint
In actively dividing cells, the G1, S, and G2 phases are collectively known as which of the following?
Interphase
While preparing to divide, the cell grows and copies its chromosomes during which stage?
Interphase
Which of the following describes the number of chromosomes in eukaryotic cells?
It varies considerably between different species.
The pairs of sister chromatids align themselves in a single row along a plane half-way between the poles during which phase of mitosis?
Metaphase
During the formation of the spindle apparatus what must break down?
Nuclear membrane
The bacterial genome consist of a single loop of DNA located in which of the following regions of the cell?
Nucleoid
Inhibitory phosphorylation of the kinase component of Cdc2 is catalyzed by which type of enzyme?
Phosphatase
In what cells does cytokinesis involve the formation of a cell plate?
Plant cells
Condensation of chromosomes continues throughout which phase?
Prophase
dentify the type of protein encoded by the cdc2 gene.
Protein kinase
What is the key event in anaphase?
Removal of cohesin proteins from the centromeres of sister chromatids
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 which phase of the cell cycle?
S
When is the spindle apparatus 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
During anaphase B, microtubules slide past each other pulling the poles anchored to them away from the center of the cell. At the same time, chromosomes are also pulled apart because
a different set of microtubules attaches the chromosomes to the poles.
During the __________________________ of mitosis, the centromeres of sister chromatids split apart allowing sister chromatids to move away from each other.
anaphase
The shortest stage of mitosis is ____________________.
anaphase
A cleavage furrow is typically formed during cytokinesis in ___________________________ cells.
animal
During cytokinesis in plants, the newly formed cell plate is coated with ____________________ to create two new cell walls. At this point the space between the two daughter cells is called the middle _______________________.
cellulose lamella
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
Cytokinesis in animal cells involves the formation of a ____________________furrow around the cell.
cleavage
The key event in anaphase is the removal of _____________________ proteins from the centromeres of sister chromatids.
cohesin
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
Full activation of the Cdc2 kinase requires complexing with a ________________________ and the correct pattern of phosphorylation.
cyclin
The division of the cytoplasm to produce two distinct daughter cells is referred to as _____________________.
cytokinesis
Cytokinesis is the division of the cytoplasm to produce two distinct cells which are called which of the following?
daughter
The active domains of chromatin in a nondividing nucleus are called
euchromatin
During telophase, chromosomes uncoil to allow for gene __________________
expression
During telophase, chromosomes uncoil to allow for gene ____________________.
expression
Cytokinesis involves the formation of a cleavage _______________________ in animal cells and a cell __________________________ in plant cells.
furrow plate
Cell division in bacterial cells and eukaryotic cells involves the replication and segregation of _____________________ information and the division of contents within the cell.
genetic
Two irreversible points in the cell cycle are replication of ____________________ material and _____________________ of sister chromatids.
genetic separation
The metaphase plate is a plane located
halfway between the poles.
During anaphase A, chromosomes are pulled towards opposite poles as their _________________________ microtubules become shorter.
kinetochore
During anaphase A, chromosomes are pulled towards opposite poles as their ___________________________ microtubules become shorter.
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
Sister chromatids are pulled towards opposite poles of the cell by microtubules attached to their ________________________.
kinetochores
The ______________________ membrane does not break down before mitosis in most fungi and some protists, therefore mitosis occurs within the _____________________.
nuclear nucleus
During telophase, the nuclear envelope re-forms to produce two separate __.
nuclei
The region in a bacterial cell where DNA is located is called the
nucleiod
The region in a bacterial cell where DNA is located is called the ________________________.
nucleoid
The region in a bacterial cell where DNA is located is called the _______________________.
nucleon
n most fungi and some protists, the nuclear membrane does not break down before mitosis, therefore, mitosis takes place within the
nucleus
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 ______________ is reached.
origin termination
Cdks are enzymes which regulate proteins within the cell cycle via __.
phosphorylation
During telophase, the changes made to the cell during ____________________ are reversed.
prophase
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 or duplicated
Replication of each chromosome and its centromere takes place during the ________________________ phase to produce two complete DNA molecules.
s
During the _________________ phase of the cell cycle, the chromosomes are replicated.
s or synthesis
During DNA replication the chromosomes contract and the identical halves are called ______________________ ________________________.
sister chromatids
The ________________________ apparatus is broken down during telophase.
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
The term mitosis is from the Greek "mitos," meaning
thread
Humans have ____________ chromosomes.
46
Identify the diploid number of chromosomes in humans.
46
The human cell contains a total of how many chromosomes
46
MPF is composed of two parts: a cyclin component and a ___________________________component.
kinase
Place the following interphase events in the correct order
1. Cell actively grows 2. Chromosomes are duplicated and begin to condense. 3. Centrioles are duplicated 4. Centrioles move to opposite ends of the cell.
Interphase events in the correct order
1. Cell actively grows 2. Chromosomes are duplicated and begin to condense. 3. Centrioles are duplicated. 4. Centrioles move to opposite ends of the cell.
Order the steps in binary fission from first to last, starting at the top.
1. The bacterial DNA molecule replicates 2. The cell elongates and the DNA is partitioned such that the origins are at 1/4 and 3/4 positions in the cell. 3. Septation begins 4. The cell pinches in two, forming two daughter cells.
The cells of most eukaryotes have between _________________ and __________________ chromosomes, although some species can have hundreds or even thousands of chromosomes.
10 50
The chromosome number in the body cells of most eukaryotic species falls within which range?
10 and 50
Animal embryonic cells complete the cell cycle in less than ______________________. The shortest cell cycle is found in embryonic cells of the fruit flies: ___________________ minutes.
20 8
What is the number of haploid chromosomes in humans?
23
The inactive domains of chromatin in a nondividing nucleus are referred to as _____________________.
heterochromatin
Cell division in bacterial and eukaryotic cells produces genetically__________________________ cells.
identical
During bacterial cell division, two genetically _______________ daughter cells are produced.
identical
During bacterial cell division, two genetically ______________________ daughter cells are produced.
identical
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
In an actively dividing eukaryotic cell, the G1, S, and G2 phases are collectively constitute the ________________________.
interphase
During __________________________ the chromosomes are aligned midway between the spindle poles.
metaphase
The ________________________ plate is a plane halfway between the poles along which chromosomes align during 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
