Cell Division Flashcards
What is meant by the cell cycle or cell division cycle ?
The series of events that occur in a eukaryotic cell between the formation of the cell and the time where the cell gets replicated.
The series of events that occur in a eukaryotic cell between the formation of the cell and the time where the cell gets replicated.
Cell cycle/ cell division cycle
In what type of cell does the cell cycle occur in?
Eukaryotic cells
2 main phases of the cell cycle
Interphase and mitotic phase
What is occurring in a cell during interphase?
The cell is forming and it carries on with its regular metabolic functions
The cell is forming and it carries on with its regular metabolic functions
Interphase
What is occurring during the mitosis phase?
The cell is replicating itself
In which phase does the cell replicate itself?
Mitosis phase
A fertilized cell develops into a ______ organism during the cell cycle
Mature
Name at least three things that form during the cycle
Hair
Skin
Blood cells
Internal organs
What process NEVER occurs in interphase?
Cell division
Where are chromatids found in a cell?
In the nucleus
Chromatids are made of a molecule called _______
DNA
See note called chromosome
1- chromatid
2- centromere
3- short arm
4-long arm
In what PHASE do most cells spend the majority of their lifetime?
Interphase
How often do human skin cells divide each day?
Once a day
How many hours per day is a human skin cell in interphase?
Roughly 22 hours
What type of cell may spend decades in interphase instead of dividing?
Nerve cells
Name the 3 stages in interphase
G1
S phase
G2
G1
S phase
G2
Stages in interphase
What does G1 stand for and what occurs in this stage?
Growth 1
The cell creates organelles and begins to metabolize
The cell creates organelles and begins to metabolize
G1
What does S stand for and what occurs in this stage?
Synthesis
DNA synthesis occurs in which chromosomes are copied
DNA synthesis occurs in which chromosomes are copied
S phase
What does G2 stand for and what occurs in this stage?
Growth 2
Cell grows to prepare for cell division
Cell grows to prepare for cell division
G2
From what stage of the cell cycle do cells sometimes EXIT?
G1 phase
What happens to cells that enter the G0 phase?
They are alive but they cannot divide and they do not copy their own DNA
They are alive but they cannot divide and they do not copy their own DNA
G0 phase
Name 3 types of cells that enter the G0 phase when they are mature?
Heart muscle cells, eye cells, and brain cells
What happens if G0 cells are damaged during your lifetime?
They cannot be replaced
Cytokinesis
Process where a single cell is divided into two identical daughter cells whenever the cytoplasm is divided
Process where a single cell is divided into two identical daughter cells whenever the cytoplasm is divided
Cytokinesis
What stage occurs after cytokinesis
G1 stage
What part of the cell is divided during cytokinesis
The cytoplasm
What are the new cells called and how do they compare with eachother
Daughter cells
Identical
What is the major thing happening to a cell during G1
The cell is growing and synthesizing proteins and organelles
What cell structures are made in G1
Organelles
Since proteins and _______ are being made during G1, there is a great amount of protein _______ occurring
Enzymes
Synthesis
What does the S phase stand for?
Synthesis phase
What happens during the S phase?
DNA synthesis or replication
Each chromosome originally is made of how many DNA molecules and how does this molecule appear in the chromosome?
One DNA molecule. In a chromosome it has one DNA double helix (or cromatid)
Chromatid
DNA double helix
At the end of S phase each chromosome has how many coiled DNA molecules?
Two identical DNA double helix molecules (chromatids)
What structure holds the duplicated chromosomes together and is also copied during the S phase?
Centromere
What is the final and shortest phase of interphase?
The G2 phase
About how long would a typical cell be in the G2 phase?
Four to five hours
How is the cell prepared for mitosis during the G2 phase?
It produces all of the enzymes that the cell will need in order to divide
What follows the G2 phase?
Mitosis
What part of the cell is actually dividing in mitosis?
Nucleus
What is another name for mitosis
Karyokinesis
Karyokinesis
Mitosis
When are the chromosomes duplicated - before or after mitosis?
Before
What process follows mitosis?
Cytokinesis
The nucleus is divided during _______, while cytoplasm of the cell is divided during __________
Mitosis
Cytokinesis
How do the two new cells compare with each other?
They are both identical with an equal distribution of organelles
The two new cells are called ____ cells
Daughter
Does mitosis occur in prokaryotes? Explain why or why not.
Mitosis does not occur I. Prokaryotes because they do not have a nucleus
What process is used by bacteria to divide and reproduce?
Binary fission
Body cells are called ________ cells, while reproductive cells are known as ______ cells
Somatic
Germ
Name the 4 mitotic stages
Prophase, metaphase, anaphase, and telophase
How does cytokinesis occur in an animal cell?
The cells divide the cytoplasm
By constructing the cell membrane in the center to form a cleavage forrow
How does cytokinesis occur in a plant cell?
Form a cell plate
In the center in order to divide the cytoplasm
Genetic material is called ______ during interphase and IS/IS NOT clearly visible
Chromatin
Is not
What makes The chromosomes become visible during prophase?
The DNA molecules are shortened and condensed by coiling
What Is used to help break down the nuclear membrane?
Enzymes
Besides the nucleus, what else is broken down during prophase?
Nucleolus
What forms during prophase to later attach and move chromosomes?
Spindle fibers
Doubled chromosomes are held together by the ________
Centromeres
Where do chromosomes line up during metaphase?
At the equator
During what stage are sister chromatids separated and moved to opposite ends of the cell?
Anaphase
Four things that happen during telophase
Nucleotides reform
Nuclear envelope reform
Chromosomes uncoil
Spindle fibers disintegrate
Nucleotides reform
Nuclear envelope reform
Chromosomes uncoil
Spindle fibers disintegrate
Telophase
See plant cells in mitosis
Name them
Interphase
Metaphase
Prophase
Anaphase
Telophase
How long does interphase take up
90% of the cell cycle
90% of the cell cycle
Interphase
G1
Cell grows and carries out regular functions
Cell grows and carries out regular functions
G1
G0
Cells that are not capable of dividing and if the cell dies they can not be replaced
Cells that are not capable of dividing and if the cell dies they can not be replaced
G0
From where do cells enter the G0 phase
G1
S-phase
Synthesis of DNA
Synthesis of DNA
S-phase
At the end of the s phase, each originals chromosome consists of two __________ connected by the _________
Chromatids
Centromere
What is the cell preparing to do in the G2 phase
Preparing to divide
Preparing to divide
G2 phase
Where is DNA checked to make sure there are no errors?
G2 phase
_________ will repair any errors in DNA that was synthesized
Enzymes
Microtubules
Cell structure that helps transport materials for cells
Cell structure that helps transport materials for cells
Microtubules
G2
Preparing to divide
Enzymes correct DNA
microtubules are rearranged for mitosis
Preparing to divide
Enzymes correct DNA
microtubules are rearranged for mitosis
G2
In which phase are microtubules rearranged for mitosis
G2
Mitosis
Cell division
Creates new cells
Cell division
Creates new cells
Mitosis
Prophase
Nuclear membrane begins to break down
Centrosomes with centrioles inside migrate to poles of the cell (animal cells)
Centrioles
Helps the movement of chromosomes during division
Associated with the spindle
Helps the movement of chromosomes during division
Associated with the spindle
Centrioles
Nuclear membrane begins to break down
Centrosomes with centrioles inside migrate to poles of the cell (animal cells)
Prophase
In which phase does the nucleolous disappear?
Prophase
In which phase does chromatin condense into chromosomes?
Prophase
Separation of chromosomes
Prophase
Prophase is the separation of ______
Chromosomes
Formations of the mitotic spindle occurs in which phase?
Prophase
Metaphase
Chromosomes like up at the equator
Spindle fibers link chromosomes to opposite poles
Chromosomes line up at the equator
Spindle fibers link chromosomes to opposite poles
Metaphase
In which phase do chromosomes line up at the equator?
Metaphase
In which phase do spindle fibers link chromosomes to opposite poles
Metaphase
Anaphase
Centromeres divide and chromatids (now chromosomes) move toward poles as spindle fibers shorten
Centromeres divide and chromatids (now chromosomes) move toward poles as spindle fibers shorten
Anaphase
Where do chromosomes move toward poles?
Anaphase
Telophase
Nuclear membrane forms around the chromosomes at the poles
Spindle dissolves
Chromosomes uncoil
Cytokinesis begins as cleavage
Furrow forms (cell membranes pinches inward)
Nuclear membrane forms around the chromosomes at the poles
Spindle dissolves
Chromosomes uncoil
Cytokinesis begins as cleavage
Furrow forms (cell membranes pinches inward)
Telophase
In which phase does the nuclear membrane form around the chromosomes?
Telophase
In which phase does the spindle dissolve?
Telophase
In which phase do the chromosomes uncoil
Telophase
In which phase does the furrow form
Telophase
Cytokinesis
Cytoplasm of the cell divides in half equally
Two genetically identical cells are produces
Cytoplasm of the cell divides in half equally
Two genetically identical cells are produces
Cytokinesis
When does the cytoplasm of the cell divide?
Cytokinesis
Cytokinesis in plant cells
Cell plate forms across the middle of the cell to separate the two ends of the plant cell into two separate cells
Cell plate is formed by golgi vesicles
Cleavage furrow
Connecting two cells during telophase
Order of mitosis
Metaphase
Anaphase
Telophase
Cytokinesis
In which cell is the cell plate formed
Plant cell
Cancer
Uncontrolled cell division
Telomeres
Tips of chromosomes
Become shorter with each cell division and eventually the cell will no longer be able to divide
Tips of chromosomes
Become shorter with each cell division and eventually the cell will no longer be able to divide
Telomeres
Apoptosis
Cell death
Apoptosis example
Weaving between toes and fingers during development
Somatic cells
All body cells EXCEPT EGG AND SPERM CELLS
Full set of DNA/ diploid
All body cells EXCEPT EGG AND SPERM CELLS
Full set of DNA/ diploid
Somatic cells
Diploid
2 (di) sets of each chromosome (2n)
N= number of chromosome sets
Humans have 46
2 (di) sets of each chromosome (2n)
N= number of chromosome sets
Humans have 46
Diploid
Gametes
Sex cells
Haploid/ monoploid- half the DNA of every other type of body cell
Sex cells
Haploid/ monoploid- half the DNA of every other type of body cell
Gametes
Homologous
Two chromosomes that each code for the same traits (ex: one from mom and one from dad) from the opposite sex parents
Two chromosomes that each code for the same traits (ex: one from mom and one from dad) from the opposite sex parents
Homologous
Meiosis
2 rounds of cell division to reduce cells to haploid number
Reduction phase
2 rounds of cell division to reduce cells to haploid number
Reduction phase
Meiosis
Before meiosis
Interphase
Germ cells- diploid cells replicate
DNA - creating a second set of homologous chromosomes
Prophase |
Nuclear membrane breaks down
CROSSING OVER occurs
Nucleus beak down
The chromosomes appear condensed and the nuclear envelope is not apparent
What does crossing over create?
Genetic variation
Crossing over
Two sets of homologous chromosomes join and exchange bits
Two sets of homologous chromosomes join and exchange bits
Crossing over
Nuclear membrane breaks down
CROSSING OVER occurs
Nucleus beak down
The chromosomes appear condensed and the nuclear envelope is not apparent
Prophase |
Metaphase |
Pairs of homologous chromosomes (tetrads) move to the equator of the cell
Pairs of homologous chromosomes (tetrads) move to the equator of the cell
Metaphase |
Anaphase |
Homologous chromosomes move to poles of the cell
Homologous chromosomes move to poles of the cell
Anaphase |
Tetrad
2 chromosome x’s together
2 chromosome x’s together
Tetrad
Meiosis | amount of chromosomes
46 chromosomes
Meiosis || amount of chromosomes
23
Which two processes are involved in mitotic cell division
A) Nuclear duplication and cytoplasmic division
B)Nuclear duplication and cytoplasmic duplication
C)Spermatogenesis and cytoplasmic duplication
D) Oogenesis and cytoplasmic division
A
Which mitotic event in the chart occurs after the other three events have taken place
A)appearance of spindle fibers
B) Separation of chromatids by the action of spindle fibers
C) Disintegration of the nuclear membrane
D)Replication of chromosomes
B
Student using a compound light microscope is observing sells undergoing mitotic cell division. If the cells are from a bean plant, which process could the student observe?
A)The formation of a cell plate between two new cells
B)The replication of centrioles
C) Pinching in of the cell membrane to form two cells
D) The pairing of homologous chromosomes
A
What would most likely result if mitosis was not accomplished by cytoplasmic division
A)Two cells, each with one nucleus
B) Two cells, each without a nucleus
C) One cell with two identical nuclei
D) One cell without a nucleus
C
The process of mitosis usually involves
A)Chromosome duplication and synapsis
B) DNA replication and separation of chromatids
C) Tetrad formation and fertilization
D) reduction in chromosomes number and formation of cell plate
B
What is one difference between mitotic cell division in plants and mitotic cell division in animals?
A) chromosomes are replicated in plants but not in animals
B) the replicated chromosomes separate in plants but not in animals
C) a cell plate divides the cytoplasm in plants but not in animals
D) the nuclear membrane reforms in plants but not in animals
C
How many chromosomes will be found in each of the two new cells formed as a result of mitotic cell division?
A) only one-half as many chromosomes as the parent cell
B) twice as many chromosomes as the parent cell
C) three times as many chromosomes as the parent cell
D) the same number of chromosomes as the parent cell
D
The diploid chromosome number in a certain species of fish is 20. How many chromosomes would normally be found in bone cell of this fish?
20
If the diploid chromosome number of a cloned plant is 12, the chromosome number of the plant cell used to produce the cloned plant is
12
Sexual reproduction requires more energy and resource, what’s the average then?
A) it increases genetic diversity.
B) it can help prevent disease epidemics.
C) it can help us cope with environment changes.
D) all of the above
D
A diploid female lizard produces diploid offspring that are genetically identical to herself. This type of reproduction requires:
A) meiosis
B) mitosis
C) mitosis, then meiosis
D) none of the above
B
Chromosome A contains genes for an eye color of hazel. Chromosome B contains genes for hair color of hazel, and chromosome C contains genera for an eye color of blue.
A) chromosomes A and B are homologous
B) Chromosomes B and C are homologous
C) chromosomes A and C are homologous
D) None of the chromosomes are homologous to one another
C
Suppose that a cell is unable to replicate its DNA. Which of the following would not be present in this cell?
A) sister chromatids B) centromere C) DNA D) genes E)homologous chromosomes
A
True/ false
If a parent cell contained 30 chromosomes, it’s daughter cells would contain 15 following mitosis.
False
Gonads
Sex organs
Spermatogenesis
Results in 4 haploid sperm cells
Results in 4 haploid sperm cells
Spermatogenesis
Oogenesis
Results in 4 haploid cells but only 1 egg and 3 tiny polar bodies
Results in 4 haploid cells but only 1 egg and 3 tiny polar bodies
Oogenesis
Polar bodies
Produced in oogenesis (egg formation) are usually discarded
Produced in oogenesis (egg formation) are usually discarded
Polar bodies
How many polar bodies are produced in oogenesis?
3
Budding
Organism grows a new appendage that eventually creates a new organism
Yeast - yeast with a BUD
Organism grows a new appendage that eventually creates a new organism
Budding
Runners and leaf cutting
Plant roots grow out and create a new plant
Plant roots grow out and create a new plant
Runners
(Leaf cutting)
Tubers
Example
Each bud can form a new plant- genetically identical plant
Potato famine
Each bud can form a new plant- genetically identical plant
Potato famine
Tubers
Regeneration
When some organisms are cut into pieces the parts grow into new separate organisms
Starfish, worm
When some organisms are cut into pieces the parts grow into new separate organisms
Starfish, worm
Regeneration
Parthenogenesis
Development of an embryo from an unfertilized egg (fertilized by polar bodies)
Development of an embryo from an unfertilized egg (fertilized by polar bodies)
Parthenogenesis
A cell with two of each kind of chromosome is called a ______ cell
Diploid
A ______ is the cell created when a sperm enters an egg
Zygote
Zygote
The cell created when the sperm enters the egg
How many daughter cells are created at the end of meiosis 1 ?
2
How many daughter cells are created at the end of meiosis 2 ?
4
In humans, how many chromosomes are present in each cell at the end of meiosis 1 ?
46
What is the important outcome of meiosis?
Crossing over and genetic variation
Does mitosis involve the duplication of chromosomes?
Yes
Gonads
Sex cells
