Tissues, Stem Cells, & Cancer

Question 1

Multicellular organisms are built from organized collections of cells. (T or F)

Answer 1

True

Question 2

Cells are organized into what?

Answer 2

tissues

Question 3

Extracellular matrix is abundant in bone and other connective tissue. (T or F)

Answer 3

True

Question 4

How are collagen fibrils organized in skin and other tissues?

Answer 4

bundles

Question 5

Procollagen precursors are sliced to do what?

Answer 5

to form mature collagen outside the cell

Question 6

What kind of pattern are collagen fibrils in the skin arranged into?

Answer 6

a plywood-like pattern (kind of striped)

Question 7

What can cause skin to be hyper-extensible?

Answer 7

genetic defects resulting in incorrect collagen assembly

Question 8

What two proteins help attach a cell to the extracellular matrix?

Answer 8

fibronectin and integrin proteins

Question 9

What do fibronectin and integrin proteins bind to?

Answer 9

Fibronectin proteins bind to collagen fibril, and integrin proteins bind to the fibronectin to tether it to the cytoskeleton.

Question 10

When is an integrin protein activated?

Answer 10

when is binds to molecules outside of the cell

Question 11

Proteoglycans and glycosaminoglycans can form what?

Answer 11

large extracellular aggregates

Question 12

List the 5 ways cells can be packed together to form epithelial tissues

Answer 12

1. Simple - “buildings”
2. Stratified - “brick wall”
3. Columnar - “skinny towers”
4. Cuboidal - “small cubes”
5. Squamous - “flat pancakes”

Question 13

multicellular sheets in which the cells are joined together

Answer 13

epithelia

Question 14

free surface of sheet of epithelial cells

Answer 14

apical

Question 15

surface sitting on specialized sheet of extracellular matrix

Answer 15

basal

Question 16

thin, tough sheet of extracellular matrix

Answer 16

basal lamina

Question 17

What is the function of a cadherin molecule?

Answer 17

to attach one cell to another

Question 18

Inside the cell, the cadherin molecule is attached to the linker protein which is attached to the cytoskeletal filament. (T or F)

Answer 18

True

Question 19

Adherens junctions form what?

Answer 19

adhesion belts around epithelial cells in the small intestine

Question 20

Epithelial sheets cannot bend. (T or F)

Answer 20

False, they can bend to form a tube or vesicle

Question 21

link the keratin intermediate filaments of one epithelial cell to another

Answer 21

desmosome

Question 22

provide neighboring cells with a direct channel of communication/ channels that allow small molecules to pass from cell to cell

Answer 22

gap junctions

Question 23

seals neighboring cells together to prevent leakage of extracellular molecules between them/ helps polarizes a cell

Answer 23

tight junction

Question 24

joins an actin bundle in one cell to a similar bundle in neighboring cell

Answer 24

adherens junction

Question 25

anchors intermediate filaments in a cell to the basal lamina

Answer 25

hemidesmosome

Question 26

undividing, stem cells divide and differentiate into specialized cells within the tissue

Answer 26

terminal differentiation

Question 27

A terminally differentiated cell usually does not divide any further. (T or F)

Answer 27

True

Question 28

provide replacement cells for damage repair or renewal of tissues

Answer 28

stem cells

Question 29

Stem cells divide to produce either...

Answer 29

additional stem cells or terminally differentiated cells

Question 30

What and where are the 2 main tissues skin is composed of?

Answer 30

epithelial tissue on the outside and connective tissue on the inside

Question 31

outermost layer of the epidermis

Answer 31

flat dead cells

Question 32

What does the connective tissue consist of? (2)

Answer 32

1. Dermis - tough, dense 2. Hypodermis - fatty

Question 33

Why do epithelial stem cells arise in crypts and migrate apically in the gut?

Answer 33

to repopulate dying epithelial cells

Question 34

What does the Wnt signaling pathway control?

Answer 34

the production of differentiated cells in the intestinal crypt

Question 35

deep pit that protrudes into connective tissue

Answer 35

crypt

Question 36

Epidermis of the skin is renewed from stem cells in its basal layer. (T or F)

Answer 36

True

Question 37

Hematopoietic stem cells located in the bone marrow is the end of blood cell differentiation. (T or F)

Answer 37

False, it is the beginning

Question 38

What are embryonic stem cells derived from?

Answer 38

an embryo

Question 39

Embryonic stem cells can give rise to all of the tissues and cell types in the body. (T or F)

Answer 39

True

Question 40

generated by transformation of cultured cells isolated from adult tissues

Answer 40

induced pluripotent stem cells

Question 41

a loss of normal regulation of cell proliferartion and invasion of bad cells into normal tissues

Answer 41

cancer

Question 42

Chromosomal abnormalities are common in cancer. (T or F)

Answer 42

True

Question 43

Dominant (Gain-of-Function) Cancer Mutation

Answer 43

1. Proto-oncogene mutation creates oncogene 2. Activating mutation enables oncogene to stimulate excessive cell survival

Question 44

Recessive (Loss-of-Function) Cancer Mutation

Answer 44

1. Mutation inactivates one copy of tumor suppressor gene 2. Second mutation inactivates second gene copy 3. Both inactivated genes eliminates tumor suppressor gene to stimulate excessive cell survival

Question 45

Both copies of the tumor suppressor gene need to be inactive to eliminate the activity. (T or F)

Answer 45

True

Question 46

4 ways tumor suppressor gene can be inactive

Answer 46

1. Whole chromosome lost 2. Region containing gene deleted 3. Loss-of-Function mutation 4. Gene activity silenced by epigenetic changes

Question 47

How do tumors evolve? (3)

Answer 47

1. Repeated rounds of mutation 2. Proliferation 3. Natural selection

Question 48

3 pathways altered in all human cancers

Answer 48

1. Alterations in cell proliferations 2. Alterations in DNA damage response 3. Alterations in cell growth

Question 49

6 properties required for cells to produce cancer

Answer 49

1. Loss of regulation of cell proliferation 2. Loss of susceptibility to cell death 3. Avoid signaling pathways leading to differentiation 4. Genetically unstable 5. Invasiveness 6. Survival and proliferation in foreign sites

Question 50

When is a tumor diagnosed?

Answer 50

when it has grown to contain 100s of millions of cells

Question 51

Cancer incidence increases with age. (T or F)

Answer 51

True