Biology · Grades 9–12
Genetics & inheritance · Formula reference
Formula reference
Rule and assumptions
DNA base-percentage model
In the stated double-stranded DNA model, A = T and C = G; all four percentages sum to 100.
G% = (100 − 2A%)/2
Diploid to haploid
In the stated standard model, meiosis reduces two chromosome sets to one. Do not substitute a universal species count.
haploid chromosome count = diploid count/2
Expected counts in Aa × Aa
For the simple Aa × Aa model, P(aa) = 1/4. An expected count is not a guaranteed outcome in a finite sample.
expected aa count = offspring count × 1/4
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · independent educational and translation review required. Suggested grades are not official curriculum alignment.