Variation. Genetics and health
Answers are for parents and teachers.
1
Give three examples of modification variation.
Skin tanning in the sun; muscles strengthening with training; a plant grown in light being green and one in the dark pale.
2
Distinguish gene, chromosomal and genomic mutations with one example each.
Gene – one nucleotide substituted (sickle-cell anaemia); chromosomal – loss of a segment; genomic – change in chromosome number (Down syndrome).
3
Hardy–Weinberg: if q = 0.2, what percent are heterozygotes (2pq)? (Number only.)
32
4
What is medical-genetic counselling and who benefits?
A specialist assesses a family’s risk of a hereditary disease and gives information; it helps couples planning a family and people with such a disease in their family.
5
Why is it advised to avoid tobacco smoke and excessive radiation?
They are mutagens: they damage cell DNA and raise the risk of mutations and cancer.