Lab 3: Cell Division Flashcards
(15 cards)
Name the four stages of Mitosis.
Prophase, Metaphase, Anaphase, Telophase
What are the sub-phases of Interphase + explain each one?
G1: Cell is growing and metabolically active
S: DNA synthesis
G2: Preparation for division, centrosome replicate, mitochondria and chloroplasts replicate through binary fission.
How are chromosomes views during interphase?
Still surrounded by nuclear envelope.
Chromosomes are called chromatin.
What happens to the nucleus during Prophase?
The nucleoli disappears.
The sister-chromatids are visible.
The nuclear membrane breaks down.
ID the following structures (Photo)
- Cohesion protein
- Centromere region
- Kinetochore microtubules
- Kinetochore
- Metaphase Chromosome
- Sister chromatids
During Metaphase, where do the chromosomes line up?
Metaphase plate (Equator)
Where do you find the aster? What is its purpose
Mostly in animal cells.
Bc the centrosome have to stay at opposite poles, they have stabilizing microtubules that anchor to the plasma membrane.
What roles do the centrosome play during mitosis? In animal cells
They shoot microtubules that catch the chromosomes by the centromere.
They form the spindle apparatus.
What defines the beginning and end of Anaphase?
Start: The splitting of centromeres marks the beginning of anaphase.
End: Anaphase ends when the migrating chromosomes reach their respective poles.
What happens to the chromosomes during Anaphase?
Sister chromatids are pulled apart. Thus, each former chromatid is now a chromosome.
Describe Telophase, and cytokinesis in a plant cell.
The nuclear envelope reforms around each compact mass of chromosomes.
Nucleoli reappear.
Chromosomes begin to uncoil and become less distinct.
Cytokinesis is accomplished by the formation of a cell plate that begins in the centre of the equatorial plane and grows outward to the cell wall.
Name 3 differences between animal and plant cell division.
- Centrosome in animal cell, microtubule organizing centres in plant cell.
- Aster anchor to the plasma membrane in animal cell. The cell wall anchors to the spindle of fibres.
- Cleavage furrow in animal cell. Cell plate at the equator forms the new cell wall in plant cell.
Which phase of the cell cycle lasts the longest, and which phase of M phase lasts the longest?
The interphase lasts the longest.
Prophase lasts the longest in M phases.
Why is DNA more susceptible to chemical damage during metaphase and anaphase?
It is more susceptible to chemical damage because the nuclear membrane dissolved in prophase, which usually protects DNA from the chemicals in the cytoplasm.
Why are the class results a more precise and accurate measure of phase duration than are the individual results?
The class average is more accurate because it is based on more trials. Repetition is an important step in experiments because it reduces systematic and random errors. Also the more data we have, the more precise it is.
