# AP Biology Grid-Ins Practice Test 6

### Test Information

6 questions

9 minutes

1. Twenty people decide to start a new population, totally isolated from anyone else. Two of the individuals are heterozygous for a recessive allele, which in homozygotes causes cystic fibrosis. Assuming this population is in Hardy-Weinberg equilibrium, what fraction (expressed as a decimal) of people in this new population will have cystic fibrosis?

2. A certain mutation found in fruit flies (Drosophila melanogaster) is hypothesized to be autosomal recessive. The experimenter crossed two Drosophila flies that were heterozygous for the trait. The next generation produced 70 wild-type males, 65 wild-type females, 36 males with the mutation, and 40 mutant females. Calculate the chi-squared value for the null hypothesis that the mutation is autosomal recessive.

3. If the pH of a solution is calculated using the equation pH = -log[H+], what is the pH of a solution with a hydrogen ion concentration of 1.33 × 10-8?

4. A cell is in equilibrium with its surroundings. The molarity of the surrounding solution is 0.8 M. Calculate the solute potential of the surrounding solution.

The equation for solute potential is Ψs = -i CRT where

i = ionization constant (assume that it is 1)

C = molar concentration

R = pressure constant (R = 0.00831 liter MPa/mole K)

T = temperature in kelvins (room temperature is 293 K)

5. Treatment of tomato plants with a growth hormone yielded the following weights of tomatoes: 100 g, 86 g, 123 g, 98 g, 104 g, 71 g. What is the average weight of a tomato after treatment?

6. After seven days of growth, a plant's weight was 14.3 grams. The percent biomass of that plant was determined to be 23.1 percent. What amount of energy (in kcal) is stored in the plant, if the amount of stored energy = (g biomass) × 4.35 kcal?