Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIO 202 > The Cell Cycle > Flashcards

The Cell Cycle Flashcards

1
Q

What best distinguishes living vs non-living?

A

The ability to reproduce

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

Key Function of Cell Division (3):

A

1) Asexual Reproduction

2) Growth and Development

3) Cell Replacement

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

Asexual Reproduction

A

Unicellular organisms divide to form individual organisms

–> Prokaryotes, unicellular eukaryotes (yeast, amoebas, etc.)

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

Cell Division’s Role in Growth and Development

A

Multicellular organisms divide to grow –> Enables organisms to develop from a single cell to a complex cell system

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

Cell Division’s Role in Cell Replacement

A

Tissue renewal/repair:

Replacing cells that die from accidents or normal wear and tear

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

What must be highly coordinated for proper cell division?

A

The timing of DNA replication and the actual cell division

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

Genome

A

All of a cell’s DNA (all the genetic info)

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

Eukaryote vs Prokaryote Genome

A

Eukaryotes = Genome containing multiple DNA molecules

Prokaryotes = Genome containing usually only one DNA molecule

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

Chromosomes

A

DNA wrapped in protein –> DNA-Protein Complex

–> Carry genes which specify an organism’s inherited traits

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

Gene

A

A segment of DNA

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

Replicated vs UN-replicated chromosomes

A

Replicated Chromosome = “X Shape” –> TWO DNA molecules

UN-Replicated Chromosome = NOT “X shape”
–> ONE DNA molecule

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

When in the cell cycle do we see replicated chromosomes?

A

During cell division (mainly mitosis)

–> DNA is usually kept in its unreplicated form

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

What do the chromosome proteins do?

A

Control chromosome structure (folding) and function (gene expression)

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

Chromatin

A

All the DNA and proteins of chromosomes

–> (kind of referring to all chromosomes)

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

Every species has a ________________ ______________ of chromosomes

A

1) Characteristic
2) Number

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

of chromosomes DOES NOT EQUAL

A

sophistication

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

Human Somatic Cells Chromosomes

A

46 Total Chromosomes –> 23 pairs (one from mom and the other from dad to form the pairs)

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

Gamete Chromosomes

A

1/2 the number of chromosomes as a somatic cell

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

Form of DNA when NOT dividing

OR

when DNA is REPLICATING!

A

Each chromosome is in the form of a long, thin chromatin fiber (uncondensed/uncoiled)

–> Cannot see using light microscope

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

Form of DNA AFTER Replication

OR

When cell is dividing

A

The chromosomes condense; each chromatin fiber becomes densely coiled and folded (“X shape”)

–> CAN see using a light microscope

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

Sister Chromatids

A

Copies of the same chromosome that are joined together (make up the classing “X shape’)

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

What holds sister chromatids together?

A

Cohesins

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

Cohesins

A

Proteins that hold sister chromatids together along their length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Centromere

A

A specialized sequence of DNA where sister chromatids most CLOSELY attach/tether

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

A centromere is NOT a _______________

A centromere IS a _________ _______________

A

1) Location

2) DNA sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How do centromeres cause greater tethering between the sister chromatids?

A

Due to proteins that recognize and bind to centromere DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Importance of centromere

A

Important for proper splitting of the sister chromatids during segregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Chromosome Arm

A

The portion of a chromosome to either side of the centromere

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Cell Cycle

A

The life of a cell from the time it is first formed during division of a parent cell until its own division into 2 daughter cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Two main processes must alternate to allow for proper cell division:

A

1) Doubling the genome –> Chromosome replication

2) Separation of the duplicated genome into exactly one half –> Chromosome segregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The cell cycle is split into two overall phases

A

1) Interphase
2) M-Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Steps of Interphase

A

1) G1 phase
2) S phase
3) G2 phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Purpose of Interphase

A

Sets up and readies the cell to undergo mitosis and cell division

–> Accounts for around 90% of the cell cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

M-Phase

A

1) Mitosis
2) Cytokinesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

G1 Phase

A

“First Gap” AKA First Growth

–> Cell grows, producing proteins and cytoplasmic organelles

36
Q

S Phase

A

“Synthesis” phase

–> DNA/chromosome replication: the cell duplicates its chromosomes

37
Q

G2 Phase

A

“Second Gap” AKA Second Growth

–> Cell continues to grow AND completes preparations for the cell to divide

–> ** The centrosome duplicates**

38
Q

MTOC

A

Microtubule Organizing Centers

–> Structure from which microtubules emerge

39
Q

What is the Microtubule Organizing Centers (MTOC) in animals?

A

Centrosome

40
Q

Centrosome

A

A microtubule organizing center for the formation of the mitotic spindle

–> Made of TWO centrioles that are at a 90 degree angle to each other

41
Q

How many centrosomes are needed in cell division?

A

Two

42
Q

When does the centrosome duplicate?

A

In Interphase: G2 Phase

43
Q

Mitosis

A

Nuclear division (separation of replicated chromosomes)

44
Q

Steps to Mitosis:

A

1) Prophase
2) Pro-metaphase
3) Metaphase
4) Anaphase
5) Telophase

(PpMAT)

45
Q

Prophase (3)

A

3 main events take place:

1) Centrosomes begin separating die to the lengthening of the microtubules between them (formation of an early mitotic spindle)

2) Chromosomes condense (into their classic “X shape”)

3) Nucleoli disappear

46
Q

Is the nuclear envelope still present in prophase?

A

Yes

47
Q

What causes mass cell reorganization in prophase?

A

The depolymerization of cytoskeletal microtubules to release tubulin that is then recruited for formation of the mitotic spindle

48
Q

Pro-Metaphase (3)

A

3 main events take place:

1) Nuclear envelope fragments

2) Kinetochores form at each centromere of the chromosomes (2 per chromosome: 1 on each sister chromatid)

3) Microtubules from the spindle begin attaching to the kinetochores (progressing towards alignment in the middle)

49
Q

Kinetochores

A

A protein complex that assembles on the centromere of each sister chromatid

50
Q

How do kinetochores bond to the centromere?

A

Some proteins of the kinetochore are DNA binding proteins that recognize the centromere DNA sequence, making the kinetochores from there

51
Q

Kinetochore Analogy

A

Kinetochores are like “landing pads” for microtubules

52
Q

Metaphase (3)

A

3 main events take place:

1) Centrosomes are now at EXACTLY opposite poles

2) Chromosomes have all arrived at the metaphase plate (middle)

3) All kinetochores are attached to kinetochore microtubules

53
Q

Metaphase Plate

A

An imaginary plane exactly midway between the poles of the cell

54
Q

What causes the chromosomes to align at the metaphase plate?

A

A tug of war

–> Microtubules are pulling and pushing which puts OPPOSING FORCES on the chromosomes attached

55
Q

What conditions of the “tug of war” must be met in order for the chromosomes to align in the middle?

A

The opposing forces placed on the chromosomes by the microtubules must be EQUAL –> The chromosomes align in the middle and metaphase is “reached”

56
Q

Anaphase (2)

A

2 main events take place:

1) Sister chromatids separate suddenly and get pulled to opposite sides of the cell

2) Non-Kinetochore microtubules elongate which causes the cell to also elongate overall

–> The SHORTEST step of mitosis

57
Q

What begins anaphase?

A

The Anaphase Promoting Complex (APC)

58
Q

Anaphase Promoting Complex (APC)

A

A protein complex that has PROTEASE activity that, when activated, cleaves (cuts) COHESINS

59
Q

What activates APC?

A

TENSION

–> Kinetochore-microtubule interactions must be oriented specifically to achieve a level of tension that in turn ACTIVATES APC

60
Q

What is the correct kinetochore interaction with microtubules?

A

Microtubules from each respective side connect to the kinetochore closest to the side of their origin (BOTH kinetochores must be bonded to a microtubule)

–> “Back to back” attachment

–> Produces the sufficient tension that activates APC

61
Q

How does the APC protect the cell?

A

Anaphase will be delayed until all chromosome kinetochores have been properly attached to the microtubules

–> This ensures proper chromosomal segregation and that there are no errors when pulling the chromatids apart

Protects against improper segregation of the DNA

62
Q

What does APC do once activated?

A

APC proteases CLEAVE the cohesins holding the sister chromatids together which then allows the microtubules to pull them apart and to opposite poles

63
Q

Telophase (4)

A

4 main events take place:

1) 2 daughter nuclei begin to form (along with their nuclear envelopes)

2) Nucleoli Reappear

3) Chromatin becomes less tightly coiled
–> **Cannot be seen under light microscope at this point

4) Removal of the mitotic spindle: Any remaining spindle microtubules DEPOLYMERIZE

–> MITOSIS IS COMPLETE AT THIS POINT

64
Q

Cytokinesis

A

Cytoplasmic Division –> Leading to (usually) 2 daughter cells

(Process is slightly different between animals and plants)

65
Q

When does cytokinesis begin?

A

Generally begins during ANAPHASE or TELOPHASE

66
Q

What marks the beginning of cytokinesis?

A

Formation of the cleavage furrow (in animals)

67
Q

Around when does the cleavage furrow begin to form?

A

Around LATE ANAPHASE

68
Q

Cleavage Furrow

A

A shallow groove in the cell surface near the old metaphase plate

–> A CONTRACTILE RING OF ACTIN MICROFILAMENTS

69
Q

What causes the cleavage furrow to contract/pinch in?

A

The contractile ring of actin microfilaments associate with myosin protein molecules allowing the ring to contract

70
Q

What happens as the cleavage furrow ring contracts?

A

The cleavage furrow deepens until the parent cell is pinched into 2 = 2 daughter cells

71
Q

Cytokinesis Proces in PLANTS

A

1) During TELOPHASE, vesicles derived from the golgi apparatus move along microtubules to the middle of the cell

2) Vesicles COALESCE in the middle of the cell = CELL PLATE

3) Cell plate enlargens until the membrane surrounding the plate fuses with the membrane along the perimeter of the cell

= 2 daughter cells with individual plasma membranes

–> Cell wall then forms between the two cells

72
Q

In plant cytokinesis, what do the vesicles carry?

A

Materials used for building the cell plate and wall

73
Q

Binary Fission

A

= “Division in half”

A type of asexual reproduction typically observed in prokaryotes and a select few unicellular eukaryotes

74
Q

Binary Fission in Eukaryotes vs Prokaryotes

A

Eukaryotes = Involves mitosis

Prokaryotes = NO mitosis

75
Q

Bacterial Binary Fission

A

1) Chromosome replication begins at the origin = two copies of the origin, one of the copies moves to the other end of the cell

2) Origins are at 2 opposite ends of the cell
–> Replication continues and cell continues to grow

3) Replication finishes and the cell is roughly double its original size = Plasma membrane pinches inwards (by a tubulin like protein)

4) New cell wall is deposited and cell division is complete

76
Q

Bacterial chromosome is _________ and ________…

A

circular and attached to the cell membrane

77
Q

In bacterial binary fission, all newly synthesized DNA is…

A

Attached to the plasma membrane

78
Q

Mitotic Spindle

A

A microtubule based machine:

Provides MECHANICAL FORCE that drives the alignment of chromosomes during Metaphase AND the separation of sister chromatids during anaphase

79
Q

Origins of the mitotic spindle

A

centrosomes

80
Q

What is the mitotic spindle made up of?

A

Consists of fibers made of microtubules and associated proteins

81
Q

3 types of microtubules in the mitotic spindle:

A

1) Astral MT

2) Kinetochore MT

3) Overlap (“Non-kinetochore”) MT

82
Q

Astral Microtubules

A

A radial array of short microtubules that extend out from each centrosome (Gives the “star” appearance of the aster)

83
Q

Kinetochore Microtubules

A

Microtubules that actually attach to chromosome kinetochores

84
Q

Overlap Microtubules

A

AKA Non-Kinetochore MT

–> Microtubules that DO NOT bind to kinetochores but elongate to overlap and interact with each other

85
Q

Mitotic Spindle Through the Phases

A

Interphase === Centrosome duplicates

Early Prophase === 2 centrosomes are adjacent on the nuclear membrane

Prophase === Microtubules grow –> Centrosomes pushed apart

Metaphase === Each mitotic spindle is at opposite ends of the cell

Telophase === Mitotic spindle deforms

BIO 202 (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions