Lecture 8

Question 1

What are 2 types of reproduction by dividing into two?

Answer 1

1. Binary fission
2. Mitosis

Question 2

Which type of reproduction do unicellular organisms (such as prokaryotes) use?

Answer 2

Binary fission.

Question 3

Which type of reproduction do multicellular organisms (such as eukaryotes) use?

Answer 3

Mitosis.

Question 4

How does binary fission work?

Answer 4

The circular bacterial chromosome is replicated and the cell begins to separate, forming a septum in between the two cells, before completely pinching off.

Question 5

What are the 2 main phases of the eukaryotic cell cycle?

Answer 5

1. Interphase - the time in between cell division
2. M phase - when the cells divide

Question 6

What are the 3 phases within interphase?

Answer 6

1. G1
2. S
3. G2

Question 7

What are the 2 phases within M phase?

Answer 7

1. Mitosis - when the DNA is divided
2. Cytokinesis - when the cells divide

Question 8

What happens during G1 phase or gap phase 1?

Answer 8

It is the primary growth phase and the longest phase.

Question 9

What happens during S phase or Synthesis phase?

Answer 9

Replication of the DNA.

Question 10

What happens during the G2 phase or gap 2 phase?

Answer 10

Organelles are replicated and the microtubules are organized.

Question 11

What happens during the C phase or cytokinesis phase?

Answer 11

The 2 new cells separate.

Question 12

What types of cells take longer to complete the cell cycle?

Answer 12

Mature cells.

Question 13

How long do typical mammalian cells take to complete the cell cycle?

Answer 13

24 hours.

Question 14

What are 4 phases of mitosis?

Answer 14

1. Prophase
2. Prometaphase
3. Anaphase
4. Telophase

Question 15

What is a centromere?

Answer 15

A point of constriction.

Question 16

What is the kinetochore?

Answer 16

The attachment site for microtubules.

Question 17

How do chromatids stay together?

Answer 17

Both sister chromatid has a centromere that attach to each other.

Question 18

What is the prophase?

Answer 18

When the chromosomes are condensed, the spindle apparatus is assembled, and the nuclear envelope breaks down.

Question 19

How is the spindle apparatus formed?

Answer 19

Two centrioles move to opposite poles.

Question 20

What is an aster?

Answer 20

A radial array of microtubules in animals.

Question 21

Do plants have centrioles or asters?

Answer 21

no.

Question 22

What is the prometaphase?

Answer 22

When the microtubules attach to the kinetochores and the chromosomes are moved to the center of the cell.

Question 23

What is the metaphase?

Answer 23

When the chromosomes are aligned with the metaphase plate.

Question 24

What is the anaphase?

Answer 24

When the chromatids are pulled apart to opposite poles.

Question 25

What is the telophase?

Answer 25

When the spindle apparatus disassembles and the nuclear envelope forms around each set of sister chromatids and the chromatids relax.

Question 26

After separating, what are the sister chromatids called?

Answer 26

Chromosomes.

Question 27

What is cytokinesis?

Answer 27

When the cells split into equal halves.

Question 28

How is cytokinesis different in plant cells and animal cells?

Answer 28

In animals the actin filament constricts to separate the 2 cells, but in plants the cell plate forms between the nuclei.

Question 29

What are controls of the cell cycle?

Answer 29

The cell cycle has 2 irreversible points and can be put on hold at specific points called checkpoints.

Question 30

What are the two irreversible points of the cell cycle?

Answer 30

1. Once the chromosomes are replicated 2. Once the sister chromatids are separated.

Question 31

Where are the 3 checkpoints in the cell cycle?

Answer 31

1. G1/S checkpoint 2. G2/M checkpoint 3. Late metaphase checkpoint

Question 32

What is the G1/S checkpoint?

Answer 32

checkpoint where the cell decides whether or not to reproduce.

Question 33

What is the G2/M checkpoint?

Answer 33

When the cell commits the mitosis and checks to see if the DNA was replicated properly.

Question 34

What is the late metaphase checkpoint?

Answer 34

The cell checks to make sure the chromosomes are attached to the spindle.

Question 35

What are 3 cell cycle control factors?

Answer 35

1. MPF 2.Cyclins 3. cdc2

Question 36

What is MPF?

Answer 36

Maturation-promoting factor.

Question 37

What is MPF made of?

Answer 37

Cyclin and cdc2.

Question 38

What is cdk?

Answer 38

Cyclin-dependent kinase or cyclin complex.

Question 39

what is ckd important for?

Answer 39

driving the cell cycle.

Question 40

What activates and inactivates the cdk?

Answer 40

phosphorylation.