The Cell Cycle & Mitosis

Question 1

How do cells arise from other cells

Answer 1

Cell division

Question 2

What influences a cell’s division speed

Answer 2

• species
• temperature
• how much nutrients are available

Question 3

What is the process called when Prokaryotic cells multiply

Answer 3

Cell Fission

Question 4

What is required for a cell to divide?

Answer 4

If:
-two daughter cells each receive the full complement of genetic material present in the single parent cell
-parent cell must be large enough to contribute sufficient cytoplasmic components to each daughter cell

Question 5

In multicellular eukaryotic what two categories of cells they contain. Explain

Answer 5

Somatic cells
- every other cell in body (eye, liver, etc)
- soma - means body

Gamete
- used for sexual reproduction (sperm and egg)

Question 6

Eukaryotic cells divide into two ways. What are they?

Answer 6

Mitosis and Meiosis

Question 7

What are chromosomes made of?

Answer 7

Chromatin

Question 8

What does chroma translate to

Answer 8

Greek for color

Question 9

Somatic cells come in what kinds of pairs?

Answer 9

Homologous pairs

Question 10

What do homologous pairs have in common?

Answer 10

• same length
• same bonding pattern
• carry versions of the same genes (alleles) at the same location

Question 11

What are pairs of chromosomes called

Answer 11

Diploid (2n)

Question 12

What are the pairs of gametes cells called

Answer 12

Haploid (n)

Question 13

How many types of genes are their

Answer 13

20, 000 to 25, 000 types

Question 14

Name the phase when the DNA and chromosomes are copied

Answer 14

S phase
- synthesis phase

Question 15

What is the ‘attachment point’ called?

Answer 15

Centromere

Question 16

What is the difference between mitosis and meiosis

Answer 16

Mitosis
-4 phase
-somatic cells
-produces up to 2 cells
- produces daughter cells from same chromosomes as mother cell

Meiosis
- 2 parts each 4 phases
-produces up to 4 gametes
-produces haploid cells from diploid cells

Question 17

Where does the spindle assembly begin

Answer 17

Centrosomes or centrioles (in animals)

Question 18

What moves around the chromosomes during mitosis and meiosis

Answer 18

Spindle microtubules

Question 19

What are the 4 stages of mitosis

Answer 19

1. Prophase
2. Metaphase
3. Anaphase
4. Telephase

Question 20

Can you spot the chromosomes in cells in microscopes

Answer 20

No, they are usually long and thin. Hard to detect in microscopes

Question 21

What happens in late interphase (before mitosis begins)

Answer 21

• two centrosomes present
• individual chromosomes not visible
  -nuclear envelope is intact
  -nucleolus visible

Question 22

What happens during prophase?

Answer 22

-centrosomes move apart; spindle forming
- chromosomes becomes visible
-nuclear envelope breaks up
-nucleolus disappears
-microtubules attach to chromosomes
- spindle microtubules connect to sister chromatids at centromere

Question 23

Metaphase

Answer 23

-chromosomes aligned along metaphase plate

Question 24

What happens in anaphase?

Answer 24

• microtubules start to shrink
• sister chromatids pull apart
  -chromosomes move towards opposite poles of cell

Question 25

What happens during telophase

Answer 25

-two daughter nuclei form (nuclear envelopes reforming) -chromosomes begin to elongate (disappear) -cytokinesis occur

Question 26

What is process of cytokinesis called in animals

Answer 26

Cleavage furrow

Question 27

What is cleavage

Answer 27

Due to contractile ring of micro filaments

Question 28

Do plants undergo a cleavage furrow

Answer 28

No

Question 29

How do plant cells undergo cytokinesis

Answer 29

- cell plate forms from fused vesicles - fuses with the plasma membrane - then a new cell wall forms

Question 30

What are three different cell type division

Answer 30

- constantly divide (skin cells) - hardly ever divide (nerve cells) - divide if they were damaged

Question 31

What regulates cell division

Answer 31

Molecular signals which are growth factors. They are inhibitors & stimulants that are secreted so cells can decide to divide or not

Question 32

Can cells grow outside of the body

Answer 32

Yes, some cells can divide in lab conditions

Question 33

What is another way cells regulate themselves

Answer 33

Cell have checkpoints where they can pause the cell cycle if something is wrong

Question 34

Describe the three major cell cycle checkpoints

Answer 34

DNA damage checkpoint - before entering S phase: Is DNA damaged DNA replication checkpoint -at the end of G2: IS all DNA replicated Spindle assembly checkpoint - before anaphase: Are all chromosomes attached to the spindle

Question 35

What does the cell do if it detects something wrong in its checkpoint?

Answer 35

It would self destruct - apoptosis

Question 36

What is cancer?

Answer 36

When mitosis is out of control

Question 37

What are cancer cells?

Answer 37

Cells who are irregular and are not detected by cell checkpoints

Question 38

Name three characteristics of cancer cells?

Answer 38

- divide fast - ruthless - cells that do not act live cells

Question 39

What is it called when a cancer cell is all over your body

Answer 39

Metastasis

Question 40

How does a normal cell turn to cancer cell

Answer 40

Due to damages or changes to genes that regulate cell division

Question 41

What is a cancer “causing” gene called

Answer 41

Oncogene

Question 42

what are proto-oncogenes

Answer 42

Normal genes that have the potential to become cancerous if they are mutated

Question 43

What are 2 characteristics of proto-oncogenes

Answer 43

Normally involved in cell division Dozens are known

Question 44

Other than cell checkpoint, what is another way our bodies decreases our chances of cancer?

Answer 44

We produce tumor suppressors: genes that encode proteins who normally activities inhibit cell divisions

Question 45

What two things are mutated when a cell turns cancerous

Answer 45

Proto-oncogenes must be turned on (gas) Tumor suppressors must be turned off (brake)

Question 46

What was the problem with cancer treatments back then? How has it changed and what are the benefits.

Answer 46

Cancers were categorized by the type of tissue the cancer was in. Now cancers are categorized by the mutations that cause them. Treatments are better directed and is a more effective way to use treatments

Question 47

What increases your risk of cancer

Answer 47

Prolong exposure to carcinogens The older you are

Question 48

Name 2 carcinogens and type of cancer it causes

Answer 48

Smoking = lung cancer Sun/UV exposure = skin cancer

Question 49

Can viruses cause cancer?

Answer 49

Yes, for cervical cancer HPV was said to increase your chance of cervical cancer.

Question 50

Name four types of cancer treatments

Answer 50

Surgery: lumpectomy = removal of tumour itself Radiation & chemotherapy = uses radiation to destroy a tumour of cells Gene therapy = teaching cells to recognize cancer cells is a threat