Chapter 3 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What are the types of cell division?

A

2 types, mitosis and meiosis

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

Mitosis :

It produces :

A

The growth and repair of body cells

-2 genetically identical daughter cells w/ the same chromosome number as the parent cell

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

(mitosis) Each daughter cell is

A

Diploid (2n), just like its parent cell

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

Meiosis

Each resulting cell:

A
  1. Occurs on in sexually reproducing organisms
  2. it produces gametes (sperm and ova) w/ ½ the chromosome number of the parent cell
  3. Is haploid (n)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Chromosome consists of

A

A highly coiled and condensed strand of DNA

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

A replicated chromosome consists of

A

2 sister chromatids, where 1 is an exact copy of the other

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

Centromere

A

A specialized region that holds the 2 sister chromatids together

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

Spindle fibers connect the

A

Centromere to the centrosome during cell division

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

Each chromosome contains

A

2 identical chromatids connected at a centromere

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

Cell cycle

A

When living and dividing cells pass through a regular sequence of growth and division

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

Stem cells (from human embryos)

A
  1. Retain the ability to divide indefinitely

2. to differentiate into any cell type

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

Cell cycle is strictly regulated by many

A

Proteins including some called cyclins

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

Some proteins are internal regulators making sure

A

That the cell does not undergo mitosis until certain conditions are met

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

Other proteins such as growth factors are

A

External regulators of the cell cyle: speeding up, slowing it down, or even stopping it

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

Cell cycle consists of

To move from one phase to the next

A

5 stages: G1 , S, G2, mitosis, cytokinesis

The cell must pass through 3 checkpoints

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

G1

A

Newly divided cell enters this phase right after completing mitosis

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

During G1, the cell

A
  1. Increases in size

2. prepares to replicate it’s DNA

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

G-1 checkpoint

A
If the cell is:
- healthy 
- contains adequate resources 
- DNA is undamaged,
 growth factors stimulate the cell to proceed to DNA synthesis of S phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

If the cell doesn’t pass G1-checkpoint, the cell

A

Dies or enters a resting state, G0 phase

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

S-phase

A

DNA is synthesized through the process of replication

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

S-checkpoint

A

DNA synthesis is monitored for any replication errors

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

S-phase checkpoint: If the synthesis progresses without errors

A

Growth signals will stimulate the cell to proceed to G2

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

G-2

A

Cell has to produce organelles and other cellular components that will populate two new functional daughter cells

24
Q

G-2 checkpoint

A

All chromosomes must be
1. fully replicated
2.contain no other types of damage
only then can the cell enter M phase

25
Q

When errors occur in cell division, it causes the

A

Development of cancer

26
Q

More than ____% of life of a cell is spent in _______.

A

90%, interphase

27
Q

Most cells observed under a microscope are

A

In interphase

28
Q

During interphase, chromosomes

A

Replicate in preparation for cell division

29
Q

During interphase, 1 or more nucleoli become visible within the nucleus and

A

The nuclear membrane remains intact

30
Q

Interphase is made up of

A

G1, S, G2

31
Q

Mitosis is

A

Actual division of the nucleus

32
Q

Mitosis is divided into 4 phases

A

Prophase, metaphase, anaphase, and telophase

33
Q

Prophase

A
  1. Strands of chromosomes begin to condense and become visible
  2. Nucleoli disappear
  3. Spindle fibers begin to form in the cytoplasm extending from 1 centrosome to the other
  4. centrioles begin to migrate to the poles,
  5. nuclear membrane begins to disintegrate
34
Q

Metaphase

A
  1. Chromosomes line up single file located on the equator or (metaphase plate)
  2. centrosomes are at opposite poles of the cell
  3. spindle fibers run from centrosomes to the centromeres of the chromosomes
35
Q

Anaphase

A
  1. Centromeres of each chromosome separate and spindle fibers begin to pull the sister chromosomes apart
  2. anaphase is the shortest phase of mitosis
36
Q

Telophase

A
  1. Chromosomes cluster at opposite ends of the cell and the nuclear membrane reforms
  2. supercoiled chromosomes begin to unravel and tor return to their pre-cell division condition as long , threadlike strands
  3. the nuclear membrane reforms
37
Q

Cytokinesis

A

Division of the cytoplasm

38
Q

In animal cells, a cleavage furrow forms

A

Down the middle of the cell as the cytoplasm pinches inward and the 2 daughter cells separate from each other

39
Q

In plant cells, a cell plate forms down

A

The middle of the cell

40
Q

Daughter cells do not

A

Separate from each other ,instead a sticky middle lamella cement adjacent cells together

41
Q

Meiosis

A

A form of cell division in which cells having the diploid chromosome number (2n) produce gametes (sex cells) with the haploid chromosome number (n)

42
Q

Meiosis occurs in

A

2 stages, meiosis I and meiosis II

43
Q

Meiosis I is also called

A

Reduction division

44
Q

What occurs in meiosis I?

A

Synapsis and crossing-over

45
Q

Synapsis

A

Chromosomes pair up precisely w/ their homologue so that crossing-over can occur

46
Q

Crossing-over

A

The process in which homologous chromatids exchange genetic material, it ensures greater variety in the gametes

47
Q

Homologous chromosomes separate, failure to separate is

A

Nondisjunction

48
Q

Next, chromosomes line up randomly on the

A

Equatorial plate and separate independently

49
Q

This means that how 1 pair of chromosomes lines up and separates

A

Has no effect on how any other pair of chromosomes lines up and separates

50
Q

Each resulting gamete is

A

Genetically unique

51
Q

Meiosis II

A

Sister chromatids separate

52
Q

This division

A

Maintains the haploid number of chromosomes

53
Q

This phase completes the goal of meiosis

A

Producing 4 genetically unique cells from 1 original mother cell

54
Q

In metaphase I of meiosis I

In metaphase II of meiosis II

A

Chromosomes are lined up double files

Chromosomes are lined up single files

55
Q

Summary:

A

Mitosis is for growth/repair and meiosis is for the production of gametes only

56
Q

Summary of meiosis I and II

A

I: homologous pairs separate
II: sister chromatids separate