chapter 11

Question 1

there are slides before this

Answer 1

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Question 2

adult stem cells

Answer 2

undifferentiated cells found in tissues or organs that can give rise to a limited number of cells (ex: brain, bone marrow, blood, blood vessels, skeletal muscle,skin, liver)

some of these cells have been induced to grow into other types of tissues and organs (multipotent) - cells are prepared to become different kinds of cells

Question 3

problems with adult stem cells

Answer 3

1. more difficult to obtain and grow in culture than embryonic stem cells
2. do not tend to survive as long as embryonic stem cells (don’t continue to reproduce for as many generations as embryonic stem cells)

Question 4

advantages of adult stem cells

Answer 4

1. few ethical issues
2. the person’s body will not tend to reject new the tissue, if the orginal tissue came from his or her body (whereas people will often reject things that come from different people)

Question 5

amniotic epithelial cells

Answer 5

some stem cells extracted from the placenta are called amniotic epithlial cells

thought to retain the ability of form any type of cell (pluripotent)

Have been used to make artificial heart valves, working tracheas, as well as muscle, fat, bone, heart, neural and liver cells

Question 6

advantages of amniotic epithelial cells

Answer 6

1. since the placenta is commonly discarded after birth, they could be an easy source of non-controversial stem cells
2. pluripotent
3. few ethical concerns

Question 7

problems of amniotic epithelial cells

Answer 7

may not be as potent as embryonic cells

Question 8

cloning

Answer 8

stimulating one cell to replicate and differentiate into a whole multicellular organism, identical to the orginal organism

Question 9

Dolly

Answer 9

the first animal that was cloned - sheep

Question 10

ethical concerns with cloning

Answer 10

• many attempts before it worked in sheep and other animals
• many attempts produce deformed organisms
• health of clone? Dolly died prematurely

Question 11

cancer

Answer 11

considered a genetic disease because it results from changes in the DNA; these changes are caused by mutations (base substitutions and deletions; mutations caused by chemicals, radiation, and sometimes viruses)

Question 12

cancer as a genetic disease

Answer 12

these changes occur only in the genes that reulate cell division and cell growth (not just any genes)

Question 13

genes that ____ may experiences changes

Answer 13

1. stimulate cell division - turn on cell division (proto-oncogene)
2. suppress cell division - turn off cell division (tumor suppressor genes)

Question 14

proto-oncogenes

Answer 14

normal and necessary genes that regulate cell division and cell growth; “on” switches; these are good and necessary genes because they keep up going and continue replications… they are our friends

Question 15

oncogene

Answer 15

proto-oncogenes that have had a mutation in some part of their DNA causing them to always be turned “on”

stimulating the cell which means it keeps dividing; these are not good

Question 16

tumor suppressor genes

Answer 16

regulatorygenes that normally turn “off” cell division; “off” swithces; mutations in their gene sequences can make them code for nonfunctional proteins; 3d shape is incorrect so they don’t signal the cell to stop dividing

Question 17

cancer cell development

Answer 17

multiple mutations needed to change a normal cell to a malignant cell - cancer cell (usually 3-4 changes in the DNA of a cell will cause it, on and off switches) - one oncogene activated and three tumor suppressor genes must be inactivated

Question 18

what causes multiple mutations

Answer 18

cancer cells divide very rapidly and sometimes pass (or skips)checkpoints that are looking for errors in DNA replication (gap 1 and gap 2 during interphase are in charging of checking DNA to make sure nothing got messed up)

Question 19

cancer prevalence as a result of age

Answer 19

the rate of cancer deaths clibs steeply after 40 an even more after 60 because the older a person gets, the more they have been exposed to agents that can cause mutatinos (more opportunities for changes to occur in DNA) and becuase immune systems becomes less effective with age

Question 20

carcinogens

Answer 20

agents that cause cancer

Question 21

mutagens

Answer 21

cause mutations; most mutagens are carcinogens