Topic 3a Part 3 Flashcards
What is cell division required for?
Growth, maturation, and maintenance of tissues
What occurs during the mitotic phase?
A cell undergoes mitosis to form 2 new nuclei and then divides to form 2 new individual cells
What is cytokinesis?
The process of dividing the duplicated DNA of a cell into two new nuclei
What are the distinct stages of mitosis?
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
What happens during prophase?
DNA condenses, organizes, and the classic chromosome structure appears
What occurs during prometaphase?
Microtubules attach to the chromosomes
What is the key event during metaphase?
Chromosomes align
What happens during anaphase?
Chromosomes separate
What occurs during telophase?
Nuclear membranes reappear around the two sets of chromosomes
What is the outcome of mitosis?
2 new cells are formed
What is the cell cycle?
The series of events that a cell goes through in order to divide and replicate
How often is a cell duplicated in many eukaryotic cells?
Every 24 hours
What comprises interphase?
- G1
- S
- G2
What is the G1 phase?
The first growth stage of interphase where the cell grows and performs biochemical functions
What is the first growth stage of interphase called?
G1
G1 stands for Gap 1
What happens during the G1 phase of interphase?
The cell grows to nearly its full size and performs specific biochemical functions
These functions aid the organism’s overall processes
What is the S phase of interphase responsible for?
DNA replication
The S phase stands for synthesis phase
What occurs during the G2 phase of interphase?
The cell finishes growing and prepares for mitosis
Two centrosomes appear in the cytoplasm during this phase
How long does mitosis last for a typical eukaryotic cell?
About 80 minutes
This duration can vary depending on the cell type
What is the first stage of mitosis called?
Prophase
Prophase is characterized by the condensation of chromosomes
What structural changes occur during prophase?
Chromosomes condense and microtubules appear from centrosomes
The nucleolus also disappears during this stage
What begins during prometaphase?
The breakdown of the nuclear membrane
Spindle fibers grow from centrosomes during this phase
Fill in the blank: During G1, the cell grows and performs specific _______.
biochemical functions
These functions support cellular processes
True or False: The centrosomes duplicate during the S phase.
True
Centrosomes are crucial for organizing microtubules during mitosis
What happens to the nuclear membrane during prophase?
The nuclear membrane is broken down.
What are microtubule strands also known as?
Spindle fibres.
What is the kinetic core attached to?
The centromere of each sister chromatid.
What occurs during metaphase?
Sister chromatids align along the centre of the cell.
What is the role of microtubules during anaphase?
Microtubules shorten to separate sister chromatids.
What happens to the poles of the cell during anaphase?
The poles of the cell move farther apart.
What is the final stage of mitosis?
Telophase.
What occurs during telophase?
A new nuclear membrane surrounds the chromosomes.
What is mitosis followed by?
Cytokinesis.
What is the contractile ring’s role during cytokinesis?
It compresses the cell to divide it into nearly equal halves.
What organelles are replicated and divided during cytokinesis?
- Mitochondria
- Golgi bodies
- Rough ER
- Chloroplasts
What stage do the two new cells enter after cytokinesis?
G1 stage of interphase.
What is the first phase of mitosis?
Prophase.
What occurs to DNA during prophase?
DNA condenses into chromosomes.
What marks the transition to prometaphase?
The appearance of microtubules.
Fill in the blank: During ________, chromosomes are aligned at the centre of the cell.
metaphase
True or False: Mitosis results in the formation of one new cell.
False.
What returns to an uncondensed state at the end of telophase?
Chromosomes.
What is the first stage of mitosis?
Prophase
In prophase, DNA condenses into chromosomes and microtubules appear.
What occurs during prometaphase in mitosis?
Nuclear membrane breaks down and microtubules attach to chromosomes
This stage is crucial for chromosome movement.
What is the key event during metaphase?
Chromosomes align at the center of the cell
This alignment is essential for proper separation during the next phase.
What happens during anaphase?
Chromosomes move apart to opposite poles of the cell
This ensures that each new cell will receive an identical set of chromosomes.
What characterizes the telophase stage of mitosis?
Appearance of new nuclear membranes
This stage signifies the end of mitosis.
What is the final process of cell division called?
Cytokinesis
Cytokinesis is when the cell membrane splits, resulting in two new cells.
What organelles are divided between the two new cells after mitosis?
- Mitochondria
- Golgi bodies
- Rough ER
- Chloroplasts
These organelles are essential for the functioning of the new cells.
What phase do the two new cells enter after cytokinesis?
G1 stage of interphase
This stage is part of the cell cycle where cells grow and perform their specialized functions.
Fill in the blank: Mitosis begins with _______.
Prophase
True or False: The chromosomes are moving apart during metaphase.
False
Chromosomes align at the center during metaphase, not move apart.
What are the two phases during the cell cycle?
- Interphase
- Mitosis
Interphase includes G1, S, and G2 phases, while mitosis is the process of cell division.
