Cell Cycle Part I: Overview and Interphase in Detail
1.
For a given cell, the time required for the cell cycle depends on what?
The amount of genetic material present and the job description of the cell will dictate the
time required for the cell cycle.
2.
Use the following table to summarize the different phases of interphase.
Phases
Description
*Cell grows, makes new molecules and components, and
performs normal cellular reactions
st
1 growth phase
*The majority of the cell cycle is spent in this phase Cell
(G1)
grows, makes new molecules and components, and performs
normal cellular reactions
*The majority of the cell cycle is spent in this phase
*DNA duplicates and forms identical copies of each
chromosome
*Each identical chromosome (now called a chromatid) is
Synthesis phase
held together by a centromere
(S)
*Chromatids are in the form of chromatin and are not visible
under the microscope
*Microtubules accumulate and organize
2nd growth phase
(G2)
*Cell continues to grow and new organelles are made
*Cell prepares for M phase
Use the diagram to describe the following:
3.
What is the object labeled A?
A chromosome
4.
What process does the arrow signify?
Duplication of the chromosome
5.
What are the twin objects labeled B?
Sister chromatids, each chromatid is a
chromosome
full
6.
What is the object at C and what does it
do?
A centromere made up of highly compacted DNA holds the sister chromatids together
7.
The cytoskeleton begins to grow during S-Phase. What is a cytoskeleton and what does it
do?
The cytoskeleton is a network of protein fibers maintain the shape of the cell
Cell Cycle Part II: M-Phase (Mitosis) Overview and Prophase in Detail
1.
Use the following diagram to identify each step of mitosis and cytokinesis.
A. prophase
B. metaphase
C. anaphase
D telophase
E. cytokinesis
2.
Are the steps illustrated in the correct sequence? Yes
3.
What steps are involved in Mitosis?
prophase, metaphase, anaphase, and telophase
4.
What steps are involved in the M-phase?
prophase, metaphase, anaphase, telophase, and cytokinesis, OR mitosis and cytokinesis
5. Use this diagram to answer the following questions about prophase. Each question
corresponds to a labeled image.
A.
What happens to the nuclear envelope?
It fragments into vesicles
B.
What happens to the nucleolus?
It disappears or disintegrates
C.
What forms from pole to pole?
The mitotic spindle made of microtubules
D.
Where do microtubules attach to sister chromatids?
At the centromeres
E.
Where do the microtubules transport the sister chromatids?
To the metaphase plate, or equator
Cell Cycle Part III: Metaphase, Anaphase, Telophase
Use the diagram to fill in the blanks with the appropriate terms.
1.
The entire structure labeled (A) is considered a chromosome. It is made up of two sister
chromatids, which are held together by a centromere. Each sister chromatid contains
identical DNA.
Terms: centromere, DNA, sister chromatids, chromosomes
2.
Once two sister chromatids (a chromosome) pull apart in anaphase they are no longer
considered chromatids. Therefore, the structures labeled (B and C) that were once
considered sister chromatids are now called complete individual chromosomes. Each
individual chromosome (B and C) contains identical DNA.
Terms: anaphase, chromatids, DNA, chromosomes
Use the diagram below to answer the following questions about telophase.
3.
Describe what is happening to the mitotic spindle.
Parts of the microtubules that form the spindle stretch out and help elongate the cell OR
The microtubules that were attached to chromosomes begin to break down
4.
Describe what is happening to the centrosomes.
They are disintegrating
5.
Describe what is happening to the chromosomes.
Microtubules that were once attached to the chromosomes disappear.
At each end of the cell, chromosomes unravel into chromatin threads.
6.
Describe what is happening to each nuclear envelope and nucleus.
Vesicles release fragments of the original nuclear envelope. The cell uses those original
parts to make new nuclear envelopes. The nucleus reforms.
7.
What happens to the cytoplasm in the cell during cytokinesis?
The cytoplasm splits to form two new cells
8.
What is the term for the new cells that are formed during cytokinesis?
daughter cells
Cell Cycle Part IV: Cytokinesis
1.
This illustration shows progressive stages of cytokinesis in an animal cell. What makes
this process different from a plant cell undergoing
cytokinesis?
Myosin and actin, also found in muscle tissue,
encircle and
pinch the plasma membrane. The midbody is
severed,
and two fully enclosed daughter cells are
formed.
2.
This illustration shows a stage of cytokinesis in
Use the labeled images below to complete the
by filling in the blanks.
a plant cell.
sentences
In plant cells, the (A) Golgi apparatus makes (B) vesicles that transport cell wall precursors to
form the (C) cell plate. These components are transported along (D) microtubules remaining
from the mitotic spindle.
This illustration shows progressive stages in cell wall formation during plant
cell cytokinesis (top to bottom).
3.
What is the cell plate made up of?
The cell plate is made up of a double membrane
4.
Where does the cell wall form?
The cell wall forms between the double membrane layers of the cell plate. In
other words, the cell plate is scaffolding for cell wall formation.
5.
What are the similarities of cytokinesis that are shared by animal cells
and plant cells?
The cytoplasm splits, two daughter cells are formed, each new daughter cell
contains a set of identical chromosomes