ANSWERS RATED A+
✔✔hepatitis b and c cause cancer by - ✔✔chronic inflammation of the liver
✔✔fruits and vegetables have - ✔✔protective effects from cancer
✔✔vitamin supplements have - ✔✔not been shown to reduce the risk of cancer
✔✔selenium and vitamin e - ✔✔increases the risk of prostate cancer
✔✔physical activity has been shown to - ✔✔reduce the risk of colon, breast, and
endometrial cancer
many others just not as strong of an association
✔✔virus can cause cancer by - ✔✔insertion of a gene into highly transcribed region or
chronic inflammation of the organ, more cell division = more chance for cancer mutation
to occur
✔✔radiation exposure - ✔✔uva = damages skin
uvb = absorbed by ozone
uvc = most detrimental but is filtered by the ozone
all three cause skin wrinkles
✔✔big take home message - ✔✔most cancers can be prevented through behavioral
change
✔✔50-90% of cancer is due to - ✔✔environmental factors
✔✔the US spends the most on what but has the lowest what - ✔✔the most on
healthcare out of other countries but still has one of the lowest life expectancies
✔✔all causal factors ... - ✔✔are risk factors for cancer BUT NOT all risk factors are
causal
ie. not all risk factors are cause of mutation (age does not directly cause mutation, just
increases chance of having mutation occur)
✔✔risk factors are properties - ✔✔that are statistically associated with increases
chance of a person developing cancer but are neither necessary or sufficient to cause
cancer
✔✔carcinogens are - ✔✔physical, chemical, or biological agents that cause cancer via
direct or indirect mutagenic effect
, ✔✔example of chemical carcinogens - ✔✔compounds in asbestos, cigarettes or
chemotherapeutic agents
✔✔example of physical agents - ✔✔ultraviolet radiation and ionizing radiation
✔✔mutagenic viruses - ✔✔insert their own dna into host cell chromosomes
✔✔dr maley cancer evolution - ✔✔
✔✔cancer rates per 100,000 people from 1950-2004 are - ✔✔unchanged, 193.9 in
1950 to 185.8 in 2004
✔✔cancer first appeared - ✔✔2 billion years ago with multicellularity
✔✔multicellular covenant - ✔✔somatic cells divide in organism and germline cells carry
genes to pass to offspring, cancer breaks that covenant
✔✔5 traits that cancer expresses - ✔✔uncontrolled proliferation
inappropriate cell survival
environmental degradation
dysregulated differentiation
resource monopolization
✔✔petos paradox points out - ✔✔that the incidence of cancer is not a direct correlation
of the amount of cells in the organism,
mice have more cancer than humans, and humans have more cancer than elephants
although mice and humans have far less cells than elephants
✔✔one reason elephants may express less cancer is that - ✔✔elephants have 20
copies of 53 in their genes, 40 alleles are dedicated to p53
this causes elephants to be very sensitive to dna damage
elephants have drastically more apoptosis than other organisms
✔✔initiation is - ✔✔the 1st mutation that contributes to cancer development
✔✔chapter 1. mutation in tumor suppressor - ✔✔ignores anti-growth signals,
cells continues to divide and form a tumor
✔✔chapter 2. progression of cancer leads to - ✔✔progression
leads to clonal expansion
generates its own growth signals
✔✔chapter 3. loss of survival factor from neighbor cells - ✔✔leads to apoptosis in cells