Mitosis Notes

Question 1

Centro-

Answer 1

Central

Question 2

-mere

Answer 2

Part, segment

Question 3

-some

Answer 3

Body

Question 4

-logous

Answer 4

Proportional or equivalent to

Question 5

Homo-

Answer 5

Same

Question 6

Hap-

Answer 6

Single, simple

Question 7

Kineto-

Answer 7

Moveable

Question 8

Karyo-

Answer 8

Cell nucleus

Question 9

Mit-

Answer 9

Thread

Question 10

-osis

Answer 10

Act, process or condition

Question 11

LIMITS TO CELL SIZE

Answer 11

-DNA “Overload”:
-Exchanging Materials/Ratio of Surface Area to Volume:
-

Question 12

Exchanging Materials/Ratio of Surface Area to Volume:

Answer 12

-As a cell gets bigger, its volume (x
3) grows at a faster rate
than its surface area (x
2).
-Eventually the cell cannot transport enough materials
across its membrane to survive.

Question 13

DNA “Overload”:

Answer 13

-As cell gets too large, DNA cannot supply instructions

to make enough protein for the entire cell to function

Question 14

There are two categories of cells in your body:

Answer 14

Somatic Cells

- Gametes

Question 15

What is cellular revision and how do multi-cellular organisms grow

Answer 15

Cellular Reproduction (Mitosis) occurs when one cell
divides and forms two new cells
- Multicellular organisms can only grow by increasing the number of
cells through cell division

Question 16

Why do cells divide

Answer 16

Cells must……
- Pass an exact copy of their genes to new cells
Produce NEW cells that replace worn out or damaged cells, to heal cuts, repair damaged tissues, replace cells that have a short life-span.
- There are limits on cell division: Hayflick Limit

Question 17

Cells are triggered to divide by……

Answer 17

• Contact Inhibition

- Chemical Signals

Question 18

Interphase DNA

Answer 18

DNA is never alone!
- DNA and its associated histones are known
as chromatin
- “Fried Egg” Cell

Question 19

Prophase DNA

Answer 19

When DNA is in coiled form, called
chromosomes
- During cell division, DNA will replicate (copy), only during this time does DNA coil in chromosomes
 If this were a human cell, there would
be 46 chromosomes now visible in
nucleus

Question 20

Centromere

Answer 20

Center of chromosome that holds replicated chromatids in the middle/connects chromatids

Question 21

Centrioles

Answer 21

Churros, help in formation of spindle fiber

Question 22

Centrosomes

Answer 22

Structure around centrioles that actually forms the spindle fibers

Question 23

Are chromosomes specific to species

Answer 23

Yes

Question 24

Homologous chromosomes

Answer 24

In sexually reproducing organisms, chromosomes occur in

pairs called homologous (same) chromosomes

Question 25

Diploid and Haploid in humans

Answer 25

Humans have a diploid number of 46 and haploid number of 23

Question 26

Gametes

Answer 26

Sperm and eggs cells (gametes) have 23 chromosomes and are haploid

Question 27

Somatic cell chromosomes

Answer 27

- Somatic cells have 46 (or 23 homologous pairs) and are diploid - Remember the human sex chromosomes? (autosomes- 1-22 versus sex chromosomes-XX or XY, #23)

Question 28

``` -What information can we get from these karyotypes? -How many different types of chromosomes do humans have?` ```

Answer 28

-Sex, down syndrome, etc -23 The two singlets close together aren't replicated unless they have X shape and centrosome -Chromosome 23 is sex chromosome (XX for girls XY for guys)

Question 29

Main parts of the cell cycle:

Answer 29

``` - 3 phases of interphase (G1,S,G2) - Mitosis (M Phase) - Cytokinesis - G0 Stage Nerve cells Heart muscle cells ```

Question 30

Chemical Signals

Answer 30

Cyclin - Commitment points - P53

Question 31

Cyclin

Answer 31

Protein that moves the cell cycle from G1 to Mitosis.

Question 32

P53

Answer 32

P53 prevents cell from completing the cell cycle if: - DNA is damaged - Cell has suffered other types of damage If damage is minor, p53 halts cell cycle until the damage is repaired – OR – if the damage is major or cannot be repaired, p53 triggers apoptosis or cell death.

Question 33

Types of Reproduction

Answer 33

Asexual (Binary Fission) Reproduction - This is __Prokaryotic, unicellular eukaryoitic________________. - Sexual Reproduction - This is eukaryotic, not mitosis -> meiosis__

Question 34

Interphase

Answer 34

- Period of growth, development and rest for cell 3 distinct phase - G1: Cell grows in size - S: DNA that makes up the chromatin replicates/doubles - G2: Cell undergoes rapid growth and prepares to divide, organelles double in number

Question 35

Mitosis

Answer 35

``` Process of nuclear division in preparation for cell division -Phases of mitosis Prophase Metaphase Anaphase Telophase (with Cytokinesis) ```

Question 36

Prophase

Answer 36

- Nucleoli and nucleus disappear - Centrosomes form centrioles by dividing in half and moving to opposite sides of the cell - Spindle fibers (asters) begin to form - Chromosomes form

Question 37

Anaphase

Answer 37

-Chromatid pairs separate from each other - This stage ends when chromatids reach the poles of the cell

Question 38

Telophase

Answer 38

- Chromatids relax to form chromatin - Spindle fibers disappear - Nucleus reforms around DNA - Stage ends with Cytokinesis

Question 39

Cytokinesis

Answer 39

-Cell membrane pinches inward and the two new cells separate - Animals: Cleavage Furrow - Plants: Cell Plate

Question 40

Metaphase

Answer 40

- Chromosomes line up on the equator of the cell | - Spindle fibers (mictrotubules, asters) attach to the kinetochore on the centromere of each chromosome