3A - The Cell Cycle & Mitosis

Question 1

What Is The Cell Cycle?

Answer 1

The regulated sequence of events that occurs between one cell division and the next.

Question 2

What Are The 3 Phases Of The Cell Cycle?

Answer 2

~ Interphase.
~ Mitosis (Nuclear division).
~ Cytokinesis (Cell division).

Question 3

What Is The Length Of The Cell Cycle Dependant On?
(3 Points)

Answer 3

~ Environmental conditions.
~ Cell type.
~ The organism.

Question 4

What Is The Movement From One Phase To Another Triggered By In The Cell Cycle?

Answer 4

Chemical signals called cyclins.

Question 5

When Does Interphase Occur?

Answer 5

Before mitosis.

Question 6

What Happens During Interphase?
(2 Points)

Answer 6

~ The cell increases in mass and size.
~ Continues to carry out its normal cellular functions.

Question 7

What Are The 3 Phases In Interphase?

Answer 7

~ G1 phase (Gap phase 1).
~ S phase (Synthesis phase).
~ G2 phase (Gap phase 2).

Question 8

What Happens During The G1 Phase?
(3 Points)

Answer 8

~ Organelles replicate.
~ High levels of transcription and translation occurs.
~ Size of the cell increases.

Question 9

What Happens During The S Phase?
(2 Points)

Answer 9

~ Chromosomes are replicated.
~ DNA synthesis occurs.

Question 10

What Happens During The G2 Phase?
(4 Points)

Answer 10

~ Energy stores used in the s phase are replaced.
~ Continues to carry out transcription and translation.
~ Any damaged chromosomes are repaired.
~ The cell continues to grow.

Question 11

When Does Mitosis Occur?

Answer 11

After interphase.

Question 12

What Is Mitosis?

Answer 12

The process of nuclear division by which two genetically identical daughter nuclei are produced that are also genetically identical to the parent cell nucleus.

Question 13

What Is Mitosis Needed For?
(3 Points)

Answer 13

~ The growth of multicellular organisms.
~ Repairing damaged tissues.
~ Asexual reproduction.

Question 14

What Is Mitosis Also Referred To As?

Answer 14

The M phase.

Question 15

What Are The 4 Stages Of Mitosis?

Answer 15

~ Prophase.
~ Metaphase.
~ Anaphase.
~ Telophase.

Question 16

What Is The Acronym Used For The Stages Of Mitosis?

Answer 16

PMAT.

Question 17

What Happens During Prophase?
(5 Points)

Answer 17

~ Chromosomes condense and become visible in the nucleus when stained.
~ Nucleolus disappears and the nuclear membrane starts to break down.
~ Sister chromatids are joined at the centromere.
~ The two Centrosomes move towards opposite poles.
~ Proteins begin to form spindle fibres.

Question 18

What Happens During Metaphase?
(2 Points)

Answer 18

~ Spindle apparatus is completely formed.
~ Chromosomes are lined up at the equator of the cell.

Question 19

What Happens During Anaphase?
(3 Points)

Answer 19

~ The sister chromatids separate at the centromere, centromeres divide into two.
~ Spindle fibres begin to shorten.
~ The separated sister chromatids are pulled to opposite poles by the spindle fibres.

Question 20

What Happens During Telophase?
(6 Points)

Answer 20

~ Chromatids are now referred to as chromosomes again.
~ Chromosomes arrive at opposite poles and begin to decondense.
~ Spindle apparatus breaks down.
~ Nuclear envelopes reform around each set of chromosomes.
~ Chromosomes uncoil back to their chromatin state.
~ Nucleolus reappears in each nucleus.

Question 21

When Does Cytokinesis Occur?

Answer 21

After the M phase.

Question 22

What Is Cytokinesis?

Answer 22

The physical separation of the parent cell into two genetically identical daughter cells and occurs once a new nucleus has completely re-formed at each pole of the parent cell at the end of telophase