Mcat: Reproduction Mitosis And Meiosis

Front 1

Microtubules begin to form what structure during mitosis in prophase?

Back 1

The mitotic spindle

Front 2

Germ cells

Back 2

sperm and ova
haploid
1N

Front 3

Diploidy

Back 3

In human cells except for germ cells, there are 46 chromosomes, or 23 homologous pairs.
Every chromosome has a homologue.

2N

Front 4

Somatic cells reproduce through the process of ?

Back 4

Mitosis (involves nuclear division)

Front 5

The period of the cell's life cycle between mitotic divisions ?

Back 5

Interphase

Front 6

3 subphases of Interphase

Back 6

G1 AKA Gap phase

S AKA Synthesis phase

G2 AKA Growth phase

Front 7

S phase

Back 7

The cell reproduces it's genome in preparation for division.

Front 8

Cytokinesis

Back 8

Cytoplasmic division

Front 9

The cell-cycle phase associated with replication of the cell's genome is:

Back 9

S phase of Interphase

Front 10

During the S phase, what replicates?

Back 10

All 23 pairs of chromosomes replicate. each pair of duplicates are joined at the centromere.

Front 11

After all 23 pairs of chromosomes are replicated during the S phase, what are the duplicated chromosomes joined by?

Back 11

A centromere

Front 12

When each of a cell's chromosomes has a homologous counterpart, it's called a ________ cell

Back 12

Diploid.

When a cell's chromosomes don't have homologues, they are called Haploid. But regardless of dipoildy or hapoildy, the chromosomes are composed of double-stranded DNA.

Diploid cell does not contain two nuclei.

Front 13

If for a given organism, the diploid number is 24, then the haploid number is ?

Back 13

12.

A haploid cell contains 1/2 the # of chromosomes found in a diploid cell. A

Front 14

A diploid human cell contains __ chromosomes, or __ homologous pairs

Back 14

46 Chromosomes
23 homologous pairs

Front 15

Each member of the pair of chromosomes is termed?

Back 15

Sister chromatid

Front 16

For as long as duplicated pairs are joined at their centromeres, the cell has __ pairs of chromosomes and each chromosome comprised of a pair of ?

Back 16

23 pairs of chromosomes with a pair of sister chromatids each.

Front 17

After mitosis what process occurs?

Back 17

Division of the cytoplasm - Cytokinesis.

Front 18

Which phase of mitosis represents the chromosomes condensing to the point that they are visible under the light microscope as an X-shaped structure?

Back 18

Prophase

Front 19

During which phase of mitosis does the nucleolus slowly disappear?

Back 19

Prophase

Front 20

During which phase of mitosis do the centrioles move to opposite poles of the cell?

Back 20

Prophase

Front 21

Aster fibers form around what structure?
During which phase of mitosis?

Back 21

Aster fibers form around the centrioles during prophase.

Front 22

During which phase of mitosis do the microtubules begin to form?

Back 22

Prophase.

Front 23

What do the microtubules give rise to?

Back 23

Mitotic spindle which spans from pole to pole.

Front 24

When does the nuclear membrane begin to dissolve?

Back 24

Prophase

Front 25

What is the essential marker of early metaphase ?
(AKA prometaphase)

Back 25

Complete dissolution of the nuclear membrane

Front 26

When do the Kinetochore fibers, associated with the centromeres, interact with the mitotic spindle?

Back 26

Prometaphase

Front 27

Main function of Kinetochore fibers

Back 27

The structure that helps to align the centromeres and maintain the (pairs of sister chromatids) chromosomes along an the midpoint on the axis of the metaphase plate.

Front 28

During which phase of mitosis do the sister chromatids separate?

Back 28

Anaphase. Resulting in splitting of the centromeres too.

Front 29

When sister chromatids separate during anaphase, what is each separated chromatid termed?

Back 29

Daughter chromosome

Front 30

A Cleavage Furrow is seen during which phase of mitosis?

Back 30

Anaphase

Front 31

During which phase of mitosis do the Kinetochore Fibers disappear?

Back 31

Telophase

Front 32

What happens to the daughter chromosomes during telophase?

Back 32

They are positioned at opposite poles of the cell.

A nuclear membrane forms around each of the two generated cells containing the daughter chromosomes.

Front 33

The chromosomes are visible by light microscopy until they reach which point of mitosis?

Back 33

Telophase, after the membrane forms around each separated cell.

Front 34

When do the nucleoli disappear and reappear in mitosis?

Back 34

Disappear slowly in Prophase
Reappear in Telophase

Front 35

What marks the completion of mitosis and nuclear division?

Back 35

The reappearance of Nucleoli

Front 36

When does Cytokinesis begin?

Back 36

During the last part of anaphase or early telophase, when you see the cleavage furrow begin to form.

Front 37

When does the cell actually divide into two separate entities with regard to Mitosis?
What are the two formed cells termed?

Back 37

After Telophase when cytokinesis takes place. The cleavage furrow initially formed in Anaphase begins to deepen and ultimately divides the cell.

This forms two Daughter cells, each possessing a diploid number of chromosomes.

Front 38

What marks when the daughter cells produced by Mitosis are ready to enter interphase?

Back 38

The splitting of the cells resulting from Cytokinesis, producing two diploid daughter cells.

Front 39

Development of a cleavage furrow occurs during?

Back 39

Cytokinesis

Front 40

Which two phases of mitosis involves a change in chromosome density?

Back 40

Prophase and Telophase

At prophase, the chromosomes condense and become visible under the light microscope.

Front 41

Which phases mark the visibility and invisibility of the chromosomes to be seen under a light microscope?

What is this due to a change in?

Back 41

Become visible during: Prophase.
The chromosomes condense.


Become invisible during: Telophase.
The chromosomes decondense.

Front 42

Reduction Division

What does it produce and how is it accomplished. What is it the basis of?

Back 42

Refers to the generation of haploid daughter cells by a diploid parent cell.

Accomplished by Meiosis.

Basis of gametogenesis.

Front 43

How does Prophase I of Meiosis differ from Prophase of Mitosis?

Back 43

The homologous pairs of duplicated chromosomes align to form Tetrads. This association of homologous pairs of duplicated chromosomes is called Synapsis.

Front 44

What is Synapsis?
When does it occur?

Back 44

The homologous pairs of duplicated chromosomes align to form Tetrads.

It occurs during Prophase I of Meiosis.

It is the differing factor between Mitotic and Meiotic Prophase.

Front 45

What is the Chiasma (aka Synaptonemal Membrane) ?

Back 45

The site where the tetrads' chromatids physically bind to each other.

Chromatids may break at the chiasma.

It results in crossing over.

Front 46

At what site does Crossing Over occur during Prophase I?

What does Crossing Over cause?

Back 46

Site: Chiasma

It causes:
Physical exchange of chromatid segments between sections of homologous chromatids.
Each chromatid loses a component of it's DNA and acquires a corresponding section of DNA from it's homologue.

Front 47

What is a form of genetic recombination that is specific to Meiosis?

Back 47

Crossing over at the Chiasma during Synapsis.

Front 48

Difference in the number of chromatids aligning during metaphase of Mitosis and Meiosis?

Back 48

Mitosis: Double stranded 2 sister chromatids

Meiosis: Tetrads composed of 4 sister chromatids.

Front 49

Anaphase I marks the separation and movement to opposite poles of what type of chromosome pairs?

Back 49

Homologous chromosome pairs separate and move to opposite poles of the cell.

Front 50

Main difference between Anaphase of Mitosis and Anaphase I of Meiosis?

Back 50

Mitosis: the centromeres split
Meiosis I: the centromeres do not split

Front 51

What accurately distinguishes the difference in the result from the first division of Mitosis vs. Meiosis with regards to daughter cells?

Back 51

After mitosis, each daughter cell possesses a full complement of genetic material.

After Meiosis I, they do not. The homologues separate while their centromeres remain intact. Each Daughter cell receives only one member of each homologous chromosomal pair. The absence of the other member of the homologous pair means that each daughter cell receives half of the full parental genome.

Front 52

Daughter Cells of Meiosis I

Back 52

After Meiosis I, the homologues separate while their centromeres remain intact.

Each Daughter cell receives only one member of each homologous chromosomal pair. The absence of the other member of the homologous pair means that each daughter cell receives half of the full parental genome. (But two copies of it each joined by a centromere)

Front 53

Anaphase II

Back 53

Centromeres divide.
The 2 chromatids are pulled to opposite poles of the cell.
Cytokinesis produces 2 daughter cells.

Front 54

2 Daughter cells produced by Meiosis II each have what kind of chromatids?

Back 54

Two daughter cells are produced from each two Meiosis I daughter cells.
There is one chromatid in each cell from each original tetrad.
2 daughter cells from Meiosis I produced 4 daughter single chromatid (haploid) cells from Meiosis II.

Front 55

Mitosis vs. Meiosis: Types of cells produced at the end of each?

Back 55

Mitosis: 2 Diploid daughter cells

Meiosis: 4 Haploid daughter cells

Front 56

Centromeres split during which of Mitosis, Meiosis I, Meiosis II?

Back 56

Mitosis and Meiosis II

(Anaphase)