joshnsit wrote:
Two genes BRCA1 and BRCA2 are linked to hereditary breast cancer. Therefore in order to decrease the annual number of mammogram tests administered across a population and to more accurately assess a woman's individual risk of breast cancer, all women should be tested for these genes.
Which of the following is the assumption?
A. Some women who are tested for the two genes will subsequently undergo mammograms on a less frequent basis than they used to.
B. The majority of breast cancer patients have no family history of the disease.
C. Researchers may have identified a third breast cancer gene that is linked with hereditary breast cancer.
D. Women who have these genes have an 90% chance of getting breast cancer while women who don't have these genes have only a 20% chance of getting breast cancer.
E. The presence of BRCA1 and BRCA 2 can explain upto to 50% of hereditary cases
OA l8r
Observation: Two genes BRCA1 and BRCA2 are linked to hereditary breast cancer.
Plan: All women should be tested for these genes
Aim: Decrease the annual number of mammogram tests administered across a population and to more accurately assess a woman's individual risk of breast cancer
What is an assumption?
An assumption would be something that the plan assumes to be true for the aim to take place.
A. Some women who are tested for the two genes will subsequently undergo mammograms on a less frequent basis than they used to.
Correct. The argument is assuming that there will be a decrease in number of mammograms if women are tested for these genes. Only then can the aim of "decrease the annual number of mammogram tests administered across a population" materialise.
B. The majority of breast cancer patients have no family history of the disease.
This weakens our conclusion. It is not the assumption.
C. Researchers may have identified a third breast cancer gene that is linked with hereditary breast cancer.
Irrelevant.
D. Women who have these genes have an 90% chance of getting breast cancer while women who don't have these genes have only a 20% chance of getting breast cancer.
Certainly something that gives figures such as 90% and 20% cannot be an assumption. 0%, 50% or 100% can still play a role in certain questions but certainly not something like 20% or 90% until and unless these figures are mentioned in the original argument.
jabhatta2 - If the numbers were changed to 100% and 0% respectively, we don't NEED this to be true for our conclusion. We just want to reduce the number of tests. As long as the genes are indicative of probabilities, our argument is fine. We are looking to reduce the number of tests, not abolish them altogether.
E. The presence of BRCA1 and BRCA 2 can explain upto to 50% of hereditary cases.
Again, we don't need them to explain upto 50% of hereditary cases. They could explain only 30% or they could explain 70%. As long as the genes do explain some hereditary cases, our argument is fine.
Answer (A)
for the great explanation.
My question is regarding option B. In question stem, it says "Hereditary disease" and option B talks about "family history of disease". Can't we just discard this choice this basis only because we already know that the disease is [hereditary == family history of disease]. So this statement is not adding any new information.