10. RNAi methodology uses double-stranded pieces of RNA to trigger a breakdown or blocking of mRNA. For which of the following might it more possibly be useful? (A) to decrease the production from a harmful gain-of-function mutated gene (B) to form a knockout organism that will not pass the deleted sequence to its progeny (C) to raise the concentration of a desired protein (D) to raise the rate of production of a needed digestive enzyme
31. What may probably happen when the healthy people move away from the Mediterranean region?
(A) They may have no time to do exercise.
(B) They tend to be more responsible for their health.
(C) They tend to increase the health advantages.
(D) They might have a better chance to get heart disease and cancer.
Angelina Jolie’s chances of developing breast cancer were so high because she inherited a mutated
BRCA 1 gene from her mother, Marcheline Bertrand, who died of ovarian cancer at the age of 56. The
BRCA1 is present in everyone but only mutates in one in 1,000 people. Anyone with the mutation has a
50-80% chance of developing breast cancer. But Jolie’s risk figure was calculated to be even higher
because of other factors, including family history.
“There are various computer programs where you can input genetic information, family history and
other things and it will calculate a figure, which is why she’s got this very precise sounding number,” says
Dr. Kat Arney, a senior science manager at Cancer Research UK.
Breast cancer is already “the top cancer in women both in the developed and the developing world”,
according to the World Health Organization - and in many countries, it’s becoming more common.
Overall, a woman living in the UK has a 12% chance of getting breast cancer during her lifetime. It’s
the same in the US. But increasing longevity isn’t the only reason for the high incidence of breast
“There is an increase in rates in younger women and it’s for a number of reasons. We know that
women’s lifestyles are changing and being overweight and drinking a lot of alcohol is linked to breast
cancer risk,” says Arney.
Changes in reproductive habits are also a factor. According to Cancer Research UK, the relative
risk of developing breast cancer is estimated to increase by 3% for each year an adult woman delays
becoming a mother. Women who breastfeed also reduce their risk. The longer a woman breastfeeds,
the greater the protection. It’s estimated that risk is reduced by 4% for every 12 months of
breastfeeding. This may explain why women in richer countries have a higher risk of breast cancer.
African women are four times less likely to get the disease because they have children at a younger age,
have more of them and breastfeed them for longer.
30. Which of the following series best reflects what we know about how the flu virus moves between species?
(A) An avian flu virus undergoes several mutations and rearrangements such that it is able to be
transmitted to other birds and then to humans.
(B) The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the
pig products can be infected.
(C) A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently
and then pass it back to humans.
(D) An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new
virus mutates and is passed to a new species such as a bird, the virus mutates and can be transmitted to
19. Based on the gene and protein sequences that follow, what type of mutation-polypeptide effect has occurred?
Normal gene: ATGGCCGGCACCGAAAGAGACC
Mutated gene: ATGGCCGGCCCGAAAGAGACC
Normal protein: Met-Ala-Gly-Thr-Glu-Arg-Asp
Mutated protein: Met-Ala-Gly-Pro-Lys-Glu-Thr
(D) nucleotide insertion- missense