Test 3: Cell Cycle & Cancer

Question 1

Cell-cycle Checkpoints

Answer 1

Control mechanisms at key cell-cycle stages to ensure proper cell division (G1,G2, M)

Question 2

Chromosomal Mutations

Answer 2

Errors in chromosome duplication or distribution leading to genetic changes

Question 3

G1 Checkpoint

Answer 3

Assesses cell readiness for division, including adequate reserves and cell size, and genomic DNA damage.

Question 4

G2 Checkpoint

Answer 4

Evaluates chromosome replication and DNA damage before mitotic entry. (Also double checks cell size and protein reserves are assessed).

Question 5

M Checkpoint

Answer 5

Ensures correct attachment of sister chromatids to spindle fibers in metaphase

Question 6

Apoptosis

Answer 6

Programmed cell death to prevent release of harmful molecules

Question 7

Phagocytes

Answer 7

immune cells that engulf harmful foreign invaders and the remains of apoptotic cells

Question 8

Apoptotic Bodies

Answer 8

Fragments of a cell undergoing apoptosis, removed by phagocytes

Question 9

The timing of events in the cell cycle is controlled by mechanisms that are both __ to the cell

Answer 9

internal and external

Question 10

Types of external cell cycle signaling (4)

Answer 10

death of nearby cells, growth hormone release, crowding of cells, cell hypertrophy.

Question 11

Types of internal cell cycle signaling (2)

Answer 11

Positive & negative cell regulators

Question 12

Positive regulators (cell cycle)

Answer 12

cyclins and cyclin-dependent kinases (CDKs); two groups of proteins

Question 13

Cyclins

Answer 13

Proteins that are positive regulators of normal cell cycle progression through checkpoints (Cyclin A,B,C,D)

Question 14

Cyclins are the __ that determine the __ of the cell cycle

Answer 14

main regulatory molecules; forward momentum

Question 15

Cyclin-Dependent Kinases (CDKs)

Answer 15

Enzymes that phosphorylate proteins to advance the cell cycle

Question 16

Cyclins only regulate the cell cycle when tightly bound to __.

Answer 16

CDKs

Question 17

To be fully active, the CDK/cyclin complex must also be __ in specific locations to activate the complex

Answer 17

phosphorylated

Question 18

Phosphorylation

Answer 18

Process that activates proteins by changing their shape

Question 19

CDK Inhibitors

Answer 19

Molecules that prevent the full activation of CDKs

Question 20

Negative Regulators

Answer 20

Molecules that stop cell cycle progression

Question 21

The best understood negative regulatory molecules are __(3)

Answer 21

retinoblastoma protein (Rb), p53, and p21

Question 22

Retinoblastoma Protein (Rb)

Answer 22

Tumor suppressor protein that monitors cell size and regulates other proteins by binding to transcription factors.

Question 23

p53 protein

Answer 23

Tumor suppressor gene that monitors DNA and oxygen supply, triggering repair or apoptosis.

Question 24

p21 protein

Answer 24

Blocks CDK activation, regulated by p53 for cell cycle control.

Question 25

For the cell to move past each of the checkpoints, all positive regulators must be “turned __,” and all negative regulators must be “turned __.”

Answer 25

on; off

Question 26

Metastasis

Answer 26

Spread of cancer cells to other locations in the body

Question 27

Angiogenesis

Answer 27

Process of recruiting a blood supply to support tumor growth

Question 28

Cancer

Answer 28

a genetic disease caused by uncontrolled cell division

Question 29

Hallmarks of cancer (6)

Answer 29

grow and divide without external signals, insensitive to growth suppressors, resist cell death, immortality, invasion and metastasis, angiogenesis.

Question 30

Genetic Disease

Answer 30

Cancer results from mutations in multiple genes disrupting cell cycle control

Question 31

Biggest risk factor for cancer due to mutation accumulation

Answer 31

Age

Question 32

__ are required for cancer development in __.

Answer 32

Multiple Mutations; specific genes.

Question 33

Mutations must occur in which specific genes to develop cancer? (5)

Answer 33

tumor suppressor, DNA repair, cell cycle control, and growth factor, and other genes that alter the rate of growth or progression through the cell cycle.

Question 34

Tumor Suppressor Genes

Answer 34

Negative regulators of cell cycle, prevent uncontrolled growth.

Question 35

DNA Replication Errors

Answer 35

Small percentage passed to daughter cells, leading to mutations.

Question 36

Proto-oncogenes

Answer 36

A positive regulator of the cell cycle in normal (non-cancer) cells

Question 37

Just __ mutated proto-oncogenes develop an __ , leading to the development of cancer cells.

Answer 37

1; oncongenes

Question 38

Oncogenes

Answer 38

Genes that increase cell-cycle progression rate when altered, by a change in a cyclin-dependent kinase protein such that it was active all the time.

Question 39

Tumor growth is the result of __ growth of __ cells outpacing normal cells.

Answer 39

uncontrolled; mutated

Question 40

Hypoxia

Answer 40

Condition of reduced oxygen supply, monitored by p53.

Question 41

Cell cycle progression is controlled by __ (2)

Answer 41

proto-oncogenes and tumor suppressor genes.

Question 42

Gene mutation starts cancer when it leads to __ in cell reproduction.

Answer 42

faulty proteins

Question 43

Cell Cycle Control Mechanisms include __(2) to prevent errors.

Answer 43

redundancy and checkpoints

Question 44

Loss of function in p53 may result in (2)

Answer 44

inability to signal DNA repair enzymes or trigger p21 production