Cell Cycle Test Study Guide Flashcards
Why do cells need to divide?
to allow for:
- organism growth
- healing of injuries and wounds
*Draw a chromosome about to undergo mitosis (after S phase). Label the centromere and chromatids.
What is chromatin?
Uncoiled DNA
What stage of cell division would you find chromatin?
Interphase
What is the longest phase of the cell cycle
Interphase
How many checkpoints are in the cell cycle?
3
(G1 checkpoint,
G2 checkpoint,
Spindle checkpoint)
Where are the checkpoints and what do they do
G1: end of G1 phase
checks for: enough nutrients, damaged DNA, cell size
G2: end of G2 phase
checks for: complete DNA, damaged DNA, cell size, enough nutrients
Spindle: during metaphase
checks for: chromosome alignment, spindle attachment
When does the G1 checkpoint take place
After Gap 1
What happens during the G1 checkpoint
checks for:
enough nutrients
damaged DNA
When does the G2 checkpoint take place
end of Gap 2
What happens during the G2 checkpoint
checks for:
enough nutrients
damaged DNA
When does the spindle checkpoint take place
During metaphase
What happens during the spindle checkpoint
checks for:
- chromosome alignment
- spindle attachment to kinetochores
What are the 3 stages within interphase
- Gap 1
- Synthesis
- Gap 2
What happens in each of the stages of interphase?
Gap 1:
- growing larger physically
- creating new organelles
- cell carries normal metabolic activities
Synthesis:
- cell replicates DNA
- duplicates centrosomes
Gap 2: secondary period of growth
- cell further increases in size
- produces proteins
- moves structures around
What happens in Gap 1
- cell grows in size
- cell creates new organelles
- cell carries out normal metabolic activities
What happens in S phase
- cell replicates DNA
- cell duplicates centrosomes
What happens in Gap 2
secondary period of growth
- cell grows in size
- produces proteins
- moves around structures
What are the phases of mitosis
Prophase, Metaphase, Anaphase, Telophase
*Draw or find a picture of each phase of mitosis
Spindle fibers occur in the _ phase
Prophase
DNA replicates in the _ phase
Synthesis
Chromosomes form and become visible in _
Prophase
Chromatids break apart from each other in _
Anaphase
Nuclear membrane disappears in _
Prophase (technically prometaphase)
Chromosomes line up on the equator in _
Prophase ( technically Prometaphase)
What is the difference between animal and plant cytokinesis?
- Animal cells have a cleavage furrow and split the cell membrane
- Plant cells are not able to to do that, because of the cell wall. They create a cell plate that turns into a new cell wall.
FUN FACT! Telophase
In telophase the cell will have two nuclei in one cell before it has completely separated
What are the proteins that stimulate cell division?
helicase, SSB proteins, topoisomerase
What is a tumor?
an abnormal growth of tissue that could be cancerous or non-cancerous
What is the difference between a benign vs. a malignant tumor
Benign tumor: does not spread to surrounding healthy tissue or other parts for the body
Malignant tumor: cancerous tissue that spreads to and destroys surrounding tissue
What is it called when the cytoplasm divides in the cell cycle?
Cytokinesis
What does metastasis mean?
when cancer cells spread to other parts of the body
What is the role of the spindle fibers in cell division?
to pull apart the sister chromatids
What is the difference between chromosome and chromatin?
- Chromosomes are a highly condensed form of chromatin
- Chromatin is uncoiled DNA
**Draw a picture of chromosome and chromatin?
FUN FACT! Mitosis produces ___ that are ___ to __ and to the ___ cell
Mitosis produces two identical daughter cells that are identical to each other and to the parent cell
What does radiation and chemotherapy do?
both kill off cells that are developing (even healthy ones)
How are radiation and chemotherapy different
Radiation: targets a certain area
Chemotherapy: used on all parts of body, usually used on cancer that has spread
What are several reasons why it is difficult to find a cure for cancer?
- There are more than 100 types of cancer (different cancers for different cells)
- Not all cancers respond the same way to treatments
- Not all patients are the same
- Patients’ lifestyles are all different
Know the different parts of a nucleotide.
nitrogenous base, 5-carbon sugar, phosphate group
What type of molecule is a nucleotide?
Nucleic acid
What does the complementary base pairing rule tell us about how the DNA structure is put together?
- it pairs up with each other consistently
- it adds onto the chain by using the already existing chain as a template
What is Chargaff’s rule?
- States that Cytosine always pairs with Guanine, and Adenine always with Thymine.
- Always 1 to 1 ratio
- Always adds up to 100% total
EX:
Cytosine & Guanine - 21%,
Thymine & Adenine 29%
What were the contributions for Franklin, Watson and Crick in terms of discovering the DNA structure?
Franklin discovered DNA is in a helix
Watson and Crick used Franklin’s work, found that DNA had a double helix structure with evenly spaced pairs of bases connecting two strands
In what direction does the DNA replication occur?
5’ to 3’
(5 prime to 3 prime)
Helicase function
Breaks down hydrogen bonds (unzips nitrogenous bases/“genes”)
Ligase function
Connects the Okazaki fragments
DNA polymerase function
Adds new nucleotide bases
What is Okazaki’s fragment and why does that happen?
Okazaki’s fragment: individual fragments that have not been connected in the lagging strand
Happens because: DNA polymerase can only add new bases to a 5’ to 3’.
What is the difference between a leading and lagging strand?
Leading strand:continuously made
Lagging strand:made in fragments (called Okazaki Fragments)
How is a stem cell different from other cells?
Stem cells are not specialized.
They can do the roles and functions of any cell that they want.
What does cell differentiation mean?
the process of a stem cell differentiating into a mature specialized cell to carry out a specific job (relies on gene expression to occur)
What is histone?
The protein that makes up nucleosomes (the group of proteins that DNA winds around)
What are centrioles?
makes up centrosomes, the mitotic spindle grows out of
Purine definition
nitrogen base with two rings
(Adenine and Guanine)
(Pure = Always Good)
Pyrimidine definition
Nitrogenous base with one ring
(Cytosine and Thymine)
Antiparallel definition
The single strands in DNA run in different directions and never touch each other
Internal regulators
Proteins that regulate inside or within the cell
External regulators
Proteins that regulate outside the cell
Positive regulators
proteins that help and allow the cell to move forward in the cell cycle
Negative regulators
proteins that do not allow the cell to move forward in the cell cycle
Apoptosis
Programmed cell death
Cancer
Uncontrolled cell growth
What happens in Prophase?
- chromatin condense, becoming visible chromosomes
- breaks down nuclear envelope
- mitotic spindle forms
What happens in Prometaphase?
- chromosomes completely condense
- nuclear envelope broken down
- mitotic spindle continues to grow
- centrosomes migrate to opposite poles
- microtubules attach to the centrosomes of sister chromatids
What happens in Metaphase?
- chromosome lined up at the middle
- spindle checkpoint
What happens in Anaphase?
- sister chromatids are pulled apart and moved to opposite poles
What happens during Telophase?
- cell reforms nuclear envelope and nucleolus
- chromosomes begin to uncoil back into chromatin
- spindle breaks down
- cytokinesis happens
T/F: The risk of dying from cancer is increasing
False
T/F: Cancer can be spread from person to person
False
T/F: What someone does as a young adult has little effect on their chance of getting cancer later in life
False
T/F: There is currently a cure for cancer but the medical industry won’t tell the public about it because they make too much money treating pateints
False
T/F: Treating cancer with surgery can cause it to spread throughout the body
False
T/F: Cancer can be effectively treated
True
T/F: Cancer is a group of over 100 diseases
True
T/F: Cancer cells can be distinguished from normal cells because of their abnormal growth
True
T/F: Cancer can only occur in specific cells in the body
False
T/F: Cancer develops because of abnormal gene function
True
