AP Biology Hardy-Weinberg Essay Grading Guidelines
 Award 2 points if answers are in essay form, and not outline or bulleted
lists.
 Award 1 point if essay sections are labeled appropriately (a, b, c…etc)
Part A: (15 points total)
 Award 1 point for writing the Hardy-Weinberg equation (which is p2 + 2pq +
q2 = 1. Award 1 point for also writing p + q = 1
 Award 6 points for plugging in the numbers appropriately, and showing ALL
work. (even when the math appears easy…show work!!!)

 Award 5 points for the correct answers (1 point each for frequencies of
alleles, 1 point for frequencies of genotypes) Award 2 points for correct
process, but incorrect answer.
 Award 2 points for evidence of knowing what p, q, p2, q2 and 2pq are.
AP Biology Hardy-Weinberg Essay Grading Guidelines
Part B: (12 points)
Student will be awarded points for discussion of the following:
(1 point per bullet, for a total of 6 Points for identifying what
would happen, and 1 point per bullet for a total of 6 points for
some discussion of why that would happen)
 Identification and description of the AA genotype being the
ones affected, and dying.
 p2 frequency decreases (homozygous dominant)
 Aa frequency decreases (heterozygous)
 aa frequency increases (homozygous recessive)
 p decreases, but is not eliminated because of heterozygotes
 q increases
Part C: (10 Points)
Student will be awarded points for discussion of each of the following
bullets (5 points per bullet, for a total of 10)
 definition of microevolution
 changing allelic frequencies = microevolution, no change in allelic
frequencies = no evolution occurring
 example to show how it might happen (any that you can come up
with…like the taste lab results)
 discussion of the Hardy-Weinberg equilibrium, and what it means
The Hardy–Weinberg equilibrium is a theoretical state where allelic and
genotypic frequencies in a population remain constant from one generation
to the next, due to the absence of evolutionary influences. Because there
are always evolutionary influences present in real populations, the Hardy–
Weinberg equilibrium describes an ideal condition against which the
evolutionary effects of these influences can be analyzed mathematically.