Cellular Division

Question 1

What are the reasons (4) that cells divide?

Answer 1

• Reproduction
• Growth and Development
• Tissue Renewal
• Maintain Surface Area:Volume (SA:V) Ratio

Question 2

What are the 2 main types of cellular division?

Answer 2

• Asexual

- Sexual

Question 3

What are the 2 types of asexual cellular division?

Answer 3

• Mitosis

- Binary Fission

Question 4

What is the 1 type of sexual reproduction?

Answer 4

Meiosis

Question 5

What is the term “Genome” referring to?

Answer 5

The DNA of a cell

Question 6

What is the chromosome structure of Prokaryotes?

Answer 6

Single circular chromosome

Question 7

What is the chromosome structure of Eukaryotes?

Answer 7

• Linear chromosomes

- Cells often contain 2 copies of each chromosome

Question 8

What is the term used to describe when cells contain 2 copies of each chromosome?

Answer 8

Homologous chromosomes

Question 9

What is a chromosome?

Answer 9

Long strand of DNA wrapped around proteins (histones)

Question 10

What is the name of the protein that DNA wraps around in a chromosome?

Answer 10

Histone

Question 11

What is chromatin?

Answer 11

A highly condensed form of DNA (DNA is folded and packed tightly)

Question 12

What is the role of histones?

Answer 12

This protein associates with DNA and helps it condense into chromatin

Question 13

There are 3 components of chromosome structure. What are those 3 components?

Answer 13

• Centromere
• Telomere
• Kinetochore

Question 14

What is the Centromere?

Answer 14

Condensed region of the chromosome

Question 15

What is the Telomere?

Answer 15

Region of repetitive DNA sequences, located at the end of chromosome

Question 16

What is the Kinetochore?

Answer 16

Disc-shaped protein that spindle fibers attach to

Question 17

Chromosomes are duplicated before cellular division creating what?

Answer 17

Sister chromatids

Question 18

Where are the sister chromatids, created before cellular division, held together?

Answer 18

Centromere

Question 19

When are the sister chromatids pulled apart?

Answer 19

During mitosis

Question 20

What form of reproduction is bacterial binary fission classified as?

Answer 20

Asexual reproduction

Question 21

What are the stages (4) of interphase?

Answer 21

• Gap 1(G1)
• Synthesis(S)
• Gap 2(G2)
• G0(Gsubscript0)

Question 22

What occurs during G1 of interphase?

Answer 22

Growth, protein synthesis, organelle synthesis

Question 23

What occurs during synthesis of interphase?

Answer 23

DNA is duplicated

Question 24

What occurs during G2 of interphase?

Answer 24

Growth, synthesis of microtubules, cell cycle checkpoints

Question 25

What occurs during G0 of interphase?

Answer 25

Quiescent or "resting" state, cells NOT preparing to divide but they ARE metabolically active

Question 26

What stage of interphase are the majority of human cells in?

Answer 26

G0

Question 27

Can some cells be called back?

Answer 27

Yes (liver cells)

Question 28

How much time does a cell spend in interphase? (percent)

Answer 28

90%

Question 29

What is Mitosis?

Answer 29

Nuclear division

Question 30

What follows mitosis?

Answer 30

Cytokinesis

Question 31

What occurs during cytokinesis?

Answer 31

organelles and cytoplasm divide

Question 32

How many daughter cells are produced during mitosis?

Answer 32

2

Question 33

True/False: The 2 daughter cells formed by mitosis are identical?

Answer 33

True

Question 34

How many phases is mitosis divided into?

Answer 34

5

Question 35

What are the 5 phases of mitosis?

Answer 35

- Prophase - Prometaphase - Metaphase - Anaphase - Telophase

Question 36

What happens during Prophase?

Answer 36

- Chromosomes begin to condense | - Spindle apparatus (MTOC) begins to form

Question 37

What is the spindle apparatus, formed during the prophase, responsible for?

Answer 37

Pulling apart the chromatids

Question 38

What is the spindle apparatus composed of?

Answer 38

Microtubules and other proteins

Question 39

What happens during prometaphase?

Answer 39

- Nuclear envelope disassembles | - Spindle fibers attach to kinetochores

Question 40

What happens during metaphase?

Answer 40

Chromosomes align along the metaphase plate

Question 41

What causes the alignment of chromosomes during metaphase?

Answer 41

Tug of war between the 2 poles

Question 42

What happens during anaphase?

Answer 42

Sister chromatids are cut apart

Question 43

How are the sister chromatids cut apart during anaphase?

Answer 43

Enzymatically, the cohesion that holds them together are cleaved by enzymes

Question 44

After the cohesion between sister chromatids has been cleaved during anaphase, how are the sister chromosomes pulled to opposite poles?

Answer 44

The microtubules shorten

Question 45

What happens during telophase?

Answer 45

- Prophase events are reversed - Nuclear envelopes reform around DNA - Chromosomes unfold back into chromatin

Question 46

True/False: Cytokinesis is a part of mitosis

Answer 46

False

Question 47

During what phase of mitosis does cytokinesis start?

Answer 47

During telophase

Question 48

True/False: Cytokinesis has the same process in both animal and plant cells

Answer 48

False (review differences in notes)

Question 49

Review cell cycle regulation slide in notes.

Answer 49

Review slide in notes.

Question 50

What are the 2 main regulatory molecules in the cell cycle clock?

Answer 50

- Cyclins | - Cyclin-dependent kinases(cdks)

Question 51

True/False: Cyclin levels fluctuate cyclically

Answer 51

True

Question 52

How are cyclin-dependent kinases activated?

Answer 52

By attaching to cyclins

Question 53

True/False: cyclin-dependent kinases are present at constant concentrations but are usually inactive

Answer 53

True

Question 54

What is the G1 checkpoint?

Answer 54

"restriction point"-most important in mammals

Question 55

What happens when a cell receives a green light during the G1 checkpoint?

Answer 55

The cell continues to S phase

Question 56

What happens when a cell receives a red light during the G1 checkpoint?

Answer 56

Exits the cell cycle and enters G0 phase

Question 57

What determines whether a cell receives a red light or green light?

Answer 57

Cell size, favorable conditions, DNA damage

Question 58

True/False: Multicellular organisms do not rely on signals from other cells

Answer 58

False

Question 59

What are the components (2) of a protein dimer?

Answer 59

Cyclin and cyclin-dependent kinase

Question 60

Review Anaphase Promoting Complex (APC) slide in notes.

Answer 60

Review in cellular division.

Question 61

What are the external factors (3) of cellular division?

Answer 61

- Growth factors - Density-dependent inhibition - Anchorage dependence