AP Biology February Breakwork: Math Practice – DUE THU 2/26 (A) or FRI 2/27 (B,E,F,G)
1. Hardy Weinberg
A. In a population of 200 mice, 98 are homozygous dominant for brown fur (BB), 84 are heterozygous (Bb) and 18
are homozygous recessive for white fur (bb). If this population is in Hardy-Weinberg equilibrium calculate the
frequencies for all three genotypes.
B. The allele frequencies in a population are A =0.6 and a=0.4. What are the genotype frequencies?
C. 25% of the population does not have dimples (the recessive trait. How many individuals in a population of 2,500
would be expected to be heterozygous for this trait?
D. In sheep black wool is a recessive trait. In a flock of 250 sheep, 12 sheep were found to have black wool. Assume
that the population is in Hardy-Weinberg equilibrium. Calculate the percent of the population that is
heterozygous for this trait. Give your answer to the nearest tenth.
2. Chi Square
A. A student counts a number of cells going through the cell cycle; She counts 276 in interphase and 28 in M
phase. If we assume that 10% of the cells are expected to be actively diving, calculate the chi square value.
B. A florist crosses two flowers they are both heterozygous for long stem and red flower (LlRr). Short stem and
white flowers are the recessive traits. She gets 101 short stem with red flowers, 315 long stem and red flowers,
106 long stem and white flowers and 32 short stem with white flowers. Calculate the chi square value.
C. In a certain species of flowering plant, the red allele (R) is dominant to the white allele (r). A student carried out
a cross between a red-flowering plant and a white-flowering plant. When planted, the 158 seed that were
produced from the cross matured into 92 plants with red flowers and 66 plants with white flowers. Calculate the
chi-squared value for the null hypothesis that the red-flowering plant was heterozygous for the flower color
gene. Give your answer to the nearest tenth.
3. Water Potential
A. What is the water potential if the solute potential is -0.23 and the pressure potential is 0.30?
B. Calculate the Solute potential of a sucrose solution if the temperature is 22 C and the molarity is 0.4.
4. General Genetics Calculations
A. A student crosses two pea plants, one with the genotype AaGgRrtt and the other with the genotype aaGgRrTt.
The genes are not linked. If the student collects 384 seeds from the resulting pea pods and plants them, how
many of the offspring plants would be expected to show the recessive form of all four traits?
5. Range, Mean, Median and Mode
A. A pig farmer records the following weights for his piglets What is the Mean? Median? Mode? Range?
pig
A
B
C
D
E
F
G
Weight(lbs)
13.7
9.9
12.3
10.8
11.2
12.3
11.5
B. The following table lists the reported cases of West Nile virus in humans in Colorado from 2003 through 2010.
How many times more cases were reported in 2003 than were reported, on average in the years 2008-2010?
Year
2003
2004
2005
2006
2007
2008
2009
2010
Reported Cases of
West Nile Virus
2,947
291
106
345
578
71
103
81
6. Calculate Surface area and Volume
A. Calculate the surface area and volume for a sphere that has a diameter of 8.2 mm.
B. Calculate the surface area and volume for a cube that has the length of 3.3 mm.
C. Calculate the surface area and volume for a rectangular solid that has 2mm x 7mm x 5 mm.
7. Rate of Change
A. A human cell can be fused to a mouse cell in the laboratory, forming a single large cell (heterokaryon). This
phenomenon was used to test whether membrane proteins can diffuse throughout the plasma membrane as a
test of the fluid mosaic model.
A human cell and a mouse cell were fused together to form one cell called a heterokaryon. Initially the mouse
and human membrane proteins were on opposite sides of the heterokaryon. As time progressed, the proteins
rapidly diffused throughout the membrane. The experiment was repeated at different temperatures with the
following results.
Temperature
Cells with Mixed
(degrees C)
Protein (%)
0
0
15
8
20
42
25
77
Calculate the rate of change from 15 degrees C to 20 degrees C. Give your answer to the nearest tenth per
degree Celsius.
B. To the nearest tenth of a percent, what percentage of forested area was lost in South America from 1990-2010?
Forested Area (in millions of hectares)
Region
1990
2000
2010
Africa
750
709
674
Asia
576
570
592
Europe
989
998
1005
Oceania
199
198
191
North America
676
677
678
Central America
26
22
19
South America
946
882
864
World Total
4,168
4,061
4,033
8. Solutions
A. You have a 2M stock solution. How much of it would you dilute to create 3L of a 1M solution?
B. How many times more H+ ions are in a pH 6 solution, when compared to a pH 8 solution?
9. Standard Error of the Mean
A. A group of brothers want to see if their heights (as a group) are significantly different from the heights (as a
group) of their cousins (another group of brothers). Examine the data below, create a graph to represent the
data, and determine if the two groups are significantly different from one another with 95% confidence (±2
SEM). [This is technically not a grid-in problem, but you still need to know how to do this!]
Height of Brothers and Cousins, in centimeters
Individual #1
Individual #2
Individual #3
Mean
SEM
Brothers
150.5
170.0
160.0
160.2
8.0
Cousins
161.0
170.5
175.5
169.0
6.0
Don’t forget to also complete the Bacterial ID BLAST Lab Activity as part of your breakwork!