T10 - Cell Cycle

Question 1

Why do cells divide?

Answer 1

1. Asexual reproduction of unicellular organisms
2. Growth and development (meiosis)
3. Tissue renewal (mitosis)

Question 2

What type of cell division gives identical cells ?

Answer 2

Mitosis

Question 3

What type of cell division gives different cells ?

Answer 3

Meiosis

Question 4

For reproduction, what type of cell division do we use? Why?

Answer 4

Meiosis, because it allows for different genomes.

Question 5

What is a genome?

Answer 5

The collection of all chromosomes in an organism

Question 6

What is a chromosome?

Answer 6

Double-stranded DNA (DNA in its compact form)

Question 7

Simply put, what is the main thing chromatin helps with ?

Answer 7

Organization

Question 8

How many chromosomes does a human have? From each parent?

Answer 8

46 total, 23 from each parent

Question 9

What are the three different sets of chromosomes that we possess?

Answer 9

1. Maternal
2. Paternal
3. And one pair of sex chromosomes

Question 10

Explain how the chromatin structure can come to be ?

Answer 10

The DNA helix, negatively charged, is wrapped around the histone proteins, positively charged. They then take the chromatin structure.

Question 11

What are the maternal and paternal copies of chromosomes called ?

Answer 11

Homologous chromosomes

Question 12

What cell reproduction do somatic cells do?

Answer 12

Mitosis

Question 13

What is ploidy?

Answer 13

The number of complete sets in a cell

Question 14

What is diploid?

Answer 14

A cell with two complete sets of chromosomes (46)

Question 15

What is haploid ?

Answer 15

Cells with only one set of chromosomes (23) (gametes)

Question 16

What are allele?

Answer 16

Alternative version of the same gene

Question 17

T or F : Homologous pairs are identical? Explain.

Answer 17

They are similar, but not identical. They code for the same genes but differ in the ‘version’ of the gene.

Question 18

Why does the cell go through the cell cycle?

Answer 18

Through this cycle, the cell undergoes cycles of division allowing for new cells to be created and therefore to enable growth.

Question 19

What does cell division produce ?

Answer 19

Two identical daughter cells (from mitosis)

Question 20

When does the mitotic phase happen in the cell?

Answer 20

After G2

Question 21

What is the mitotic phase made up of ?

Answer 21

Mitosis and Cytokinesis

Question 22

What is G1 ?

Answer 22

Cell growth

Question 23

What is S phase ?

Answer 23

DNA synthesis

Question 24

What is G2 ?

Answer 24

Cell growth

Question 25

List the different phases in Interphase

Answer 25

G1 Phase ( Gap 1 Phase) S Phase (Synthesis Phase) G2 Phase (Gap 2 Phase)

Question 26

List the different phases in M phase.

Answer 26

Mitosis and Cytokinesis : Prophase Prometaphase Anaphase Telophase Cytokinesis

Question 27

What is the phase that takes up most of the cell's cycle? What is its purpos ?

Answer 27

Interphase. It aims at preparing the cell for cell division.

Question 28

Name 5 things the cell does during interphase.

Answer 28

Grow, make proteins, build new organelles, duplicate chromosomes, and more.

Question 29

Specifically, what is G1 for?

Answer 29

Obtaining energy and forming proteins.

Question 30

Specifically, what is happening in S phase ?

Answer 30

The full genome of the organism is copied (semi-conservative replication)

Question 31

What are copied chromosomes called ?

Answer 31

Sister chromatids

Question 32

What is the centromere ?

Answer 32

The point where copied chromosomes are attached to each other.

Question 33

What enzyme copies DNA ?

Answer 33

DNA Polymerase

Question 34

What is DNA polymerase ?

Answer 34

The enzyme that copies DNA.

Question 35

T or F : Sister chromatids both contain the same genetic information.

Answer 35

True

Question 36

Is cell division a precise term, does it relate to one specific thing ? Explain.

Answer 36

No, cell division varies depending on the structure and location of the cell, of the division pattern and the name of the process. Ex: Sex cell do cell division through meiosis while somatic cells do cell division through meiosis.

Question 37

After S phase, how many diploid, pairs of sister chromatids and chromatids do we have ?

Answer 37

Diploid : 2(23)=46 Pairs of s.chromatids: 46 Chromatids : 92

Question 38

Is the S phase where cell division occurs?

Answer 38

No, it's DNA replication

Question 39

What happens specifically during G2 ?

Answer 39

- We grow further and prep for cell division, meaning we produce more organelles and proteins needed for mitosis - The centrosomes duplicate and are moved apart by spindle fibers.

Question 40

Which stage has more DNA present ? G1 or G2

Answer 40

G2 (it's after S-phase)

Question 41

Why is S phase necessary ?

Answer 41

Because during cell division, the new cell will need DNA, which is duplicated for this sole purpose in S phase.