stem cells and cancer 1/2

Question 1

What is the developmental sequence starting from gametes

Answer 1

2 gametes fuse into zygote which becomes an embryo then forms germ layers then tissues

Question 2

What are stem cells

Answer 2

Undifferentiated cells that can replicate and later differentiate

Question 3

What triggers stem cell differentiation

Answer 3

Environmental or genetic cues

Question 4

What is the differentiation pathway from stem cell to final form

Answer 4

Stem cell to transit amplifying cell to terminally differentiated cell

Question 5

Where are stem cells found in the skin

Answer 5

Deep layers beneath transit amplifying and dead cells

Question 6

Why is deep skin damage dangerous

Answer 6

It can destroy stem cells increasing cancer risk

Question 7

What is totipotency

Answer 7

Ability to differentiate into any cell type including placenta

Question 8

What is pluripotency

Answer 8

Ability to differentiate into most but not all cell types

Question 9

What is multipotency

Answer 9

Ability to differentiate into related specific cell types

Question 10

What is oligopotency

Answer 10

Ability to differentiate into a few cell types

Question 11

What is unipotency

Answer 11

Ability to differentiate into one specific cell type

Question 12

What are stem cell niches

Answer 12

Specific locations that regulate stem cell function

Question 13

What is the role of stem cell niches

Answer 13

Protect stem cells and prevent overgrowth

Question 14

What are adult somatic stem cells

Answer 14

Multipotent cells found in tissues like bone marrow

Question 15

Where are foetal somatic stem cells found

Answer 15

Early developing organs and umbilical cord

Question 16

Where are amniotic stem cells found

Answer 16

Free floating in amniotic fluid

Question 17

What are germ cells

Answer 17

Cells of testes or ovaries

Question 18

What are somatic cells

Answer 18

All body cells except germ cells

Question 19

Where are stem cells in plants

Answer 19

In meristems such as SAM RAM and lateral meristems

Question 20

What is SAM

Answer 20

Shoot apical meristem at the shoot tip

Question 21

What is RAM

Answer 21

Root apical meristem at the root tip

Question 22

What is special about plant cells

Answer 22

Most are totipotent and can regenerate a whole plant

Question 23

What are embryonic stem cells

Answer 23

Pluripotent cells from early embryonic tissue

Question 24

Who was Sir Martin Evans

Answer 24

Scientist who used embryonic stem cells to make genetically modified mice

Question 25

What are induced pluripotent stem cells iPS

Answer 25

Adult cells reprogrammed to behave like embryonic stem cells

Question 26

Why are iPS cells useful

Answer 26

They avoid ethical issues of using embryos

Question 27

How can plant cells be genetically modified

Answer 27

Using callus tissue and bacteria or DNA insertion

Question 28

What are the four main uses of undifferentiated cells

Answer 28

Transformation therapeutics research and tissue engineering

Question 29

What did Mario Capecchi demonstrate

Answer 29

That homologous recombination can occur between introduced DNA and chromosomes in mammals

Question 30

What did Oliver Smithies demonstrate

Answer 30

That deficient genes in bone marrow could be corrected via homologous recombination

Question 31

Why is homologous recombination important for gene therapy

Answer 31

It allows precise genetic modification at target sites

Question 32

What medical conditions might stem cells help treat

Answer 32

Stroke TBI Alzheimer’s Parkinson’s baldness missing teeth wound healing heart attacks diabetes spinal injury

Question 33

How can stem cells help with organ growth

Answer 33

By using patient’s own cells to grow organs and avoid rejection

Question 34

Who was Henrietta Lacks

Answer 34

Her cancer cells were used to create HeLa cell line for research

Question 35

What are HeLa cells

Answer 35

Immortalised human cancer cells widely used in research

Question 36

What is a cdc mutant

Answer 36

A yeast mutant with a defect in one gene that causes cell cycle arrest at a specific point

Question 37

What does the cdc2 gene do

Answer 37

Regulates transitions from G1 to S and G2 to M phases in yeast

Question 38

What is the human equivalent of cdc2

Answer 38

CDK1 a cyclin-dependent kinase

Question 39

What does cdc2 or CDK1 do

Answer 39

Phosphorylates proteins including lamins to progress cell cycle

Question 40

What happens when cdc2 phosphorylates lamins

Answer 40

Nuclear envelope breaks down during mitosis

Question 41

What are checkpoints in the cell cycle

Answer 41

Control points where cycle stops if something is wrong

Question 42

What is cancer

Answer 42

Unregulated proliferation of cells forming a tumour

Question 43

What do tumour suppressor genes do

Answer 43

Limit cell division and promote apoptosis

Question 44

What do oncogenes do

Answer 44

Promote cell proliferation often via gain of function mutations

Question 45

Why is p53 important

Answer 45

It regulates the cell cycle and induces cell death when necessary

Question 46

What is a potential issue with p53 mutation

Answer 46

It disables regulatory control increasing cancer risk

Question 47

What are the main cancer treatments

Answer 47

Surgery radiotherapy chemotherapy and pharmaceuticals

Question 48

What do most chemotherapies target

Answer 48

Rapidly dividing cells

Question 49

Why do cancer therapies cause hair loss or gut issues

Answer 49

They target all fast dividing cells including healthy ones

Question 50

What is the cancer stem cell hypothesis

Answer 50

Only a small stem cell population sustains tumour growth

Question 51

What is the implication of the cancer stem cell hypothesis

Answer 51

Standard therapy may not remove all CSCs leading to relapse

Question 52

How do researchers test for CSCs

Answer 52

Re-seeding assay with isolated tumour cells sorted by stem cell markers

Question 53

Why are CSCs hard to treat

Answer 53

They do not divide rapidly and may resist typical chemo

Question 54

What is the good news about some failed treatments

Answer 54

They might have targeted CSCs and are now being re-evaluated

Question 55

Why might mutations in stem cells be more dangerous

Answer 55

They are passed on to more cells due to self-renewal

Question 56

Why are tumour cells often undifferentiated

Answer 56

They resemble stem cells with self-renewing capabilities

Question 57

Why is specific CSC therapy necessary

Answer 57

To ensure complete tumour eradication and prevent relapse