L3 Cell Cycle

Question 1

All cells derive from a…

Answer 1

Pre-existing cell 😉

Question 2

In eukaryotes somatic cell division occurs via mitosis. This produces…

Answer 2

Genetically identical daughter cells

Question 3

Prokaryotes divide by…

Answer 3

Binary Fission

Question 4

Rather than a distinct phase, prokaryotes replicate…

Answer 4

Throughout interphase

Question 5

FtsZ protein in prokaryotes is homologous to ? in eukaryotes

Answer 5

Actin

Question 6

The Eukaryotic Cell Cycle has 4 distinct phases

Answer 6

G1, S, G2 and Mitosis

Question 7

Mitosis can be divided into 5 steps, followed by cytokinesis

Answer 7

1. Prophase
2. Prometaphase (late prophase)
3. Metaphase
4. Anaphase
5. Telophase

Question 8

G1

Answer 8

Main growth (cellular contents, bar chromosomes, duplicate) and ✅checkpoint

Question 9

S

Answer 9

DNA (and associated protein) synthesis, chromosomes duplicate

Question 10

G2

Answer 10

Further growth and additional ‘double-check’ ✅

Question 11

Checkpoints are regulated by (3)…

Answer 11

Specific growth factors,

External factors and Kinases

Question 12

Kinases are phosphorylating enzymes which signal the cell is ready to proceed with the cell cycle, when the correct…

Answer 12

type of cyclin is present (G1, G1/S, S, M)

Question 13

Regulation of the cell cycle is important because (2)…

Answer 13

it allows detection and repair of genetic damage and prevents uncontrolled cell division

Question 14

Phase G0 (G-zero) is known as…

Answer 14

Quiescence ⏸

Question 15

Without the right signals cells proceed to either…

Answer 15

G0, or programmed cell death ☠️

Question 16

Terminally differentiated cells stop at which phase of the cell cycle?

Answer 16

G0 (G-zero)

Question 17

The cell cycle varies greatly in length. This is mostly due to the time spent in… ⏱

Answer 17

G1/G0 phases

Question 18

Important Growth Factors (GF) (3)…

Answer 18

1. PDGF (Platelet-derived)
2. FGF (Fibroblast)
3. EGF (Epidermal)

Question 19

🙅‍♀️No growth factors? Cell cycle moves to …

Answer 19

G0 phase

Question 20

Apoptosis is characterised by (4)…

Answer 20

• Nuclear condensation and fragmentation
• Blebbing of membrane, triggering phagocytosis
• Subsequent recycling of cell contents

Question 21

Necrosis is accidental cell death💀. After nuclear swelling and lysis, cell contents is released into the tissues, which is messy and can cause…

Answer 21

an inflammatory response 🤒

Question 22

Apoptosis can be activated physiologically in order to achieve (2)…

Answer 22

1. Remodelling of tissues during embryonic development (‘sculpting’)
2. Homeostasis of cell numbers ⚖️

Question 23

Apoptosis can be activated by pathogens, such as by viral toxins, or the bodies own immune system…

Answer 23

by cytotoxic-T cells or heat shock

Question 24

The p53 gene is known as…

Answer 24

“The Guardian of the Genome” 👼

Question 25

When switched on, the tutor suppressor gene p53 promotes…

Answer 25

apoptosis

Question 26

Complete the cascade following detection of DNA damage:

1. DNA damage
2. ?
3. G1 checkpoint ?
4. ?
5. ? Leak
6. ? 9, 3 & 7
7. Apoptosis

Answer 26

2. p53 activated 🔆
3. progression blocked 🛑
4. mitochondrial membrane ruptures
5. cytochrome leak 💦
6. release of Caspase 9, 3 & 7

Question 27

Both cell ? and ? are required for normal tissue development and maintenance.

Answer 27

Growth & death