MITOTIC CELL DIVISION

Question 1

Your 46 nuclear DNA molecules interact with histone proteins to form

Answer 1

46 chromatin molecules

Question 2

The benefits of packaging DNA in chromatin molecules:

Answer 2

-Reducing DNA molecule length so DNA can fit in the nucleus
-Reducing the rate of mutation
-Enabling more precise gene expression

Question 3

After DNA replication in the S phase of the cell cycle, the nucleus contains…

Answer 3

92 DNA molecules in the form of chromatin

Question 4

The spindle during mitosis

Answer 4

Separates each pair of duplicated chromosomes, which are shortened chromatin molecules called sister chromatids
This ensures that each daughter cell inherits a nucleus with 46 chromosomes

Question 5

The spindle coordinates _________ _________ during the mitosis part of mitotic cell division

Answer 5

Chromosome movement

Question 6

What is the spindle formed by?

Answer 6

Protein filaments called microtubules

Question 7

Each microtubule is formed from

Answer 7

The polymerization of tubulin proteins

Question 8

The spindle microtubules attach to a structure on each chromosome called the

Answer 8

Kinetochore

Question 9

The kinetochore is formed from

Answer 9

Specific proteins that bind to a nucleotide sequence called the centromere

Question 10

Cytoskeleton

Answer 10

Formed from microtubules

Question 11

_________ proteins in the kinetochore enable each sister chromatid to move along the spindle’s microtubules

Answer 11

Motor

Question 12

Mitotic cell division enables all eukaryotic cells to _________ and copy themselves

Answer 12

Reproduce (divide)

Question 13

Single cell eukaryotic species use mitotic cell division to

Answer 13

-Reproduce asexually
-Purge toxins
-Eliminate defective organelles

Question 14

Mitotic cell division supplies the new cells that enable your body to

Answer 14

-Grow
-Repair
-Renew (replace)
-Produce hair
-Defend itself (immune system)

Question 15

When does mitotic cell division occur?

Answer 15

During the Mitotic (M) phase of the cell cycle

Question 16

M phase

Answer 16

-Generates two, independent, function daughter cells with 46 chromosomes in the nucleus
-A complete set of organelles and other cellular structures
-Exact size required to carry out functions

Question 17

Two major processes of mitotic cell division

Answer 17

Mitosis, cytokinesis

Question 18

Mitosis produces…

Answer 18

Two nuclei in the adult stem cell to ensure that each daughter cell inherits a nucleus with 46 chromosomes

Question 19

After mitosis, the adult stem cell briefly has…

Answer 19

Two nuclei that each contain 46 chromosomes

Question 20

Mitosis enables the cell to….

Answer 20

“Duplicate the nucleus”

Question 21

First phase of mitosis

Answer 21

Prophase

Question 22

Prophase:

Answer 22

-Chromatin molecules condense into shorter chromosomes that are easier for the spindle to move
-The spindle becomes functional
-Large organelles and the cytoskeleton disassemble

Question 23

Second stage of mitosis:

Answer 23

Prometaphase

Question 24

Prometaphase

Answer 24

-The kinetochore forms at the centromere of each sister chromatid
-The spindle microtubules attach to the kinetochore
-The spindle moves all 46 pairs of sister chromatids towards the cell center

Question 25

Third stage of mitosis

Answer 25

Metaphase

Question 26

Metaphase

Answer 26

-The spindle positions all 46 pairs of sister chromatids at the cell's centre (equator) to form the metaphase plate -The mitotic phase (spindle) checkpoint verifies the attachment of spindle microtubules to every kinetochore

Question 27

Fourth stage of mitosis

Answer 27

Anaphase

Question 28

Anaphase

Answer 28

-Ensures that 46 chromosomes are delivered to opposite ends of the adult stem cell -Each sister chromatid is attached to a different half of the spindle to ensure that 46 chromosomes are delivered to opposite ends of the cell

Question 29

Anaphase A

Answer 29

Motor proteins in the kinetochore pull each sister chromatid to opposite ends of the cell

Question 30

Anaphase B

Answer 30

The two halves of the spindle move apart

Question 31

Fifth and final stage of mitosis

Answer 31

Telophase

Question 32

Telophase

Answer 32

-Each chromosome unwinds into its longer chromatin form -The nuclear envelope reforms around the 46 chromatin molecules at opposite ends of the cell to form two nuclei -The golgi apparatus and ER reform -The spindle disassembles and its released tubulin proteins are used to rebuild the cytoskeleton

Question 33

_________ begins after mitosis is complete

Answer 33

Cytokinesis

Question 34

Cytokinesis

Answer 34

The cell physically separates to produce two daughter cells

Question 35

The medical consequences of M phase (spindle) checkpoint failure

Answer 35

-The spindle cannot separate one or more pairs of sister chromatids → nondisjunction → causes aneuploidy → suppress the immune system, increase risk of cancer, increase risk of agin

Question 36

Many aneuploid cells...

Answer 36

Self destruct by apoptosis

Question 37

Aneuploidy is

Answer 37

Abnormal chromosome number in the nucleus