Question

4.How do heredity and inheritance relate to the data presented in these charts?
5.What data would you need to see in order to draw conclusions about the effectiveness of preventive surgeries?
6.What does the age at diagnosis tell you about the mutation?
7.Explain how breast cancer genes are still present in the population, despite cancer related surgeries and deaths.

Answer 1

4 - Where is your chart????

5 - Testing positive for BRCA1 cannot determine the likelihood of death, it that depends on stage, grade, hormone receptor status, etc.

6 - In general, the mutations causing early onset of disease (i.e., in childhood or early adulthood, when they affect the reproductive potential of the individual) tend to be spontaneously occurring ones. They are not the inherited kind, because the affected individual does not live long enough to pass them on. Also, they tend to be dominant to produce phenotypic results because (unless we are talking about mutations on the male X chromosomes, of which they have only one) each cell has a normal or wild type allele for the same gene on the other chromosome, which is usually sufficient to confer a normal phenotype.

By contrast, diseases caused by mutations in old age do not affect the reproductive success of the individual - they are as likely to pass the mutant gene on as a normal individual is to pass on the normal gene. So these tend to be recessive.

7 - The genes that you inherit from your parents might be recessive, so it doesn't affect the people that are alive and they continue to pass along those traits.

Answer 2

7. About 5% to 10% of breast cancers are thought to be hereditary, caused by abnormal genes passed from parent to child. Everyone has genes and some of these mutate.

Answer 3

@alphadxg

Answer 4

BRCA1 mutation
BRCA2 mutation
No BRCA mutation
Total
Number of patients
89
35
318
442
Average age at diagnosis
43.9
46.2
50.4

Preventative mastectomy*
6
3
14
23
Preventative oophorectomy*
38
7
22
67
Number of deaths
16
1
21
38
Percent died
18
2.8
6.9
8.6

Answer 5

Ok lets look at this logically, looks like mutations around the ages 50-59. So most cases of breast cancer occur after the woman has had children, so the gene, if it is present, is passed on to her children before she knows she knows that she has cancer, she might also be a carrier - spreading the mutation, but she herself is not affected, hopefully this helps.

Answer 6

let me know if you need a better explanation, that should be good though.