Cell division Flashcards

1
Q

What is DNA?

A

Deoxyribonucleic acid - all genetic info of a cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a chromosome?

A

A length of DNA and its associated proteins found in nucleus of Eukaryotic cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a Histone?

A

Protein that helps condense DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is chromotin?

A

DNA appears in this form during most of a cells life. Becomes condensed durng cellular devision.
slightly condensed DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What s the centromere?

A

Specilized constricted (pinched in) region in the condensed chromosome.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are homologous cells?

A

Similar looking chromosomes that carry the same genes also known as autosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 46 somatic chromosomes divided into?

A

22 pairs of homologous cells
and 2 sex cells that may or may not be homologous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the sex chromosomes?

A

X and Y (23rd pair)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a karyotype?

A

Picture of chromosomes - particular set of chromosomes that an individual posesses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the term Ploidy mean?

A

Measure of how many chromosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does haploid mean?

A

One copy of each chromosome (sperm and eggs) | n

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the term diploid mean?

A

Two copies of each chromosome (somatic cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the term polyploid mean?

A

More than two coppies of chromosomes (Some plants, genetic disorders)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does n repersent?

A

The number of copies of each chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why do cells need to divide?

A

Repair, growth, sexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the three stages of the cell cycle?

A

Interphase, Mitosis, Cytokenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are characteristics of interphase?

A

Cell growth and normal function
Not dividing
Composed of 3 stages: G1, S, G2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the G1 stage?

A

Apart of interphase, normal cell function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the S stage (Synthesis)

A

Synthesis of DNA, makes a copy of each chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the G2 stage?

A

Apart of interphase, growth of cell and preperation to divide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is mitosis?

A

Cell division contains four steps:
Prophase
Metaphase
Ananphase
Telophase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is cytokenesis

A

The splitting og cytoplasm, last step

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is G0?

A

Stage of interphase, not going to replicate DNA
Done by cells that dont divide (Neurons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the purpose of contractile ring?

A

Pinches rhe cell into two during cytokenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
What does a plant produce during cell division?
Cell plate, forms down middle of dividing cell, helps divide
25
What is the purpose of checkpoints in regulating the cell cycle?
To regulate the progression through the cycle.
26
What control the cell cycle?
Interactions between cyclins and cyclin-dependent kinases to control the cell cycle.
27
What may occur if a disruption interputs the cell cycle?
May result in cancer/and or programed cell death (apoptosis)
28
What are cell cycle checkpoints?
Where a cell decides to proceed with the next steps of the cell cycle.
29
What are the three most important checkpoints?
G1, G2, Spindle Checkpoint
30
What is the G1 checkpoint?
The main checkpoint for most cells Usually after this checkpoint cells will divide completly If a cell doesnt pass this ckecpoint it's said to be in G0
31
What chekcs occur at G1?
Cell size - is it big enough Nutrients Growth Factors DNA Damage
32
What occurs at the G2 checkpoint?
Checks for DNA damage - takes places after DNA replication
33
If the cell doesnt pass the G2 checkpoint what happens?
Apoptosis
34
What occurs at the spindle checkpoint?
Checks if sister chromatids are attached correctly to spindle microtubules This is the transition checkpoint between metaphase and anaphase
35
What may occur if the spindle checkpint fails?
May result in down syndrome
36
What are cyclins?
Proteins that activate kinases
37
What are protein kinases?
Enzymes that activate or inactivate other proteins by phosphotlating them Called Cyclin-dependent kinases or CDK
38
How do cell checkpoints work?
Cyclins partner with CDKs activating it as a kinases and CDK directs it's activation to other proteins resulting in passing the checkpoint
39
What is MPF?
Maturation-promoting factor A cyclin-CDK complex that was found in frog eggs
40
What is the role of MPF?
Breaks down the nuclear membrane (before mitosis/ M phase)
41
What makes cancer cells difer from othes?
Uncontrolled growth Cells are undifferential and non-functional No contact inhibition Able to move (metastasis) through blood
42
What does the term cell potency refer to?
A cells ability to differentiate into other cells
43
What is a totipotent cell?
Cells that can form all other types of cells in a body and extracellular/placental cells
44
Are adult mammal cells totipotent?
No however cells of murola are
45
What are stem cells?
Unspecilized cells - cannot form whole body hoever can form a vareity of cells/tissues
46
What are pluripotent cells?
Cells that can become any type of cell exluding placenta/umbillical chord
47
What are multipotent cells?
Stem cells that are more restricted and can form a few types of tissues ex: bone marrow cells becoming blood cells
48
What is meiosis?
The production of cells with only half of the necessary cells (gametes)
49
How does gametogensis work?
Through Ruduction division (Reduces DNA by half)
50
What is oogenesis?
Makes eggs - however only 1 of 4 becomes and egg the others become polar bodies
51
What are polar bodies?
Haploid cells that dont become eggs
52
What is spermatogensis?
Makes sperm, half of sperm get Y and other half get X
53
What is the purpose of the recombination of genes?
Increases variation - resuling in non-indentical daughter cells
54
What is the end result of meiosis?
4 Haploid cells
55
What is a tetred?
Homologous pair
56
At what point are haploid cells produced during meiosis?
After meiosis 1
57
What are the two ways that genetic variation may occur?
Independent assortment Crossing over
58
What is independent assortment?
Creation of gametes that carry different combinations of maternal and paternak chromosomes
59
What is crossing over?
The exchange of genetic material between maternal and patternal chromosomes
60
What process results in independent assortment?
During metaphase I each homolgous pair lines up at the equator In each pair the maternal and paternal homologues are randomly pulled to poles This results in different combinations
61
What process results in crossing over?
During prophase I chromosomes will form a tetrad and swap genes This produces recominants which are different from either parent
62
What is the site of crossing over called
Chiasma
63
What is non-disjunction?
The failure of homologous chromosomes or sister chromatids to seperate propery during cell division
64
What does the term synapsis refer to?
Coming together
65
What are life cycles?
The series of changes that the members of a species undergo as they pass from the beginning of a given developmental stage to the inception of that same developmental stage is a subsequent generation
66
What does a life cycle show?
When an orgnanism is haploid or diploid and how they reprodue