Download GENETICS IS NOT BLACK AND WHITE

GENETICS IS NOT BLACK AND WHITE
(catgen)
Rarely does a single gene determine a phenotype or appearance. Let’s look at the
interaction of the black and white gene. (All questions are in italics and are repeated on a
separate sheet)
I. Gene Interaction
This is the sequence of operations.
A. 2. Run the simulation
B. Chose only genes 1. W 2. B. and 5. A . Press E
C. Female, WW, BB, aa
D. Male, ww(not all white), BB and aa. (The reason that you select aa is that if you have
the tabby gene on, it will confuse the patterns)
E. The female is white and the male is black
F. Produce a litter.
G. Select constant and 8 kittens.
1. What color are kittens 3 - 10?
H. Press G for genotype.
2. What genotype are kittens 3 - 10?
I. Press return and go to the Simulation menu. Select 1. Produce a litter of kittens.
J. Mate new parents. Select any female and male as parents from cats 3 - 10.
3. How many of kittens are black in 11 - 18?
K. Repeat this breeding by using the same parents.
4. How many kittens are black in 19 - 26?
5. Out of kittens 11 - 26, what percent are black? (This is the number of black
kittens divided by 16)
L. Return to the menu and select # 3. List genotypes and phenotypes.
6. In order to be a black cat, what genotype must the W’s have?
M. Press esc to start again. Do not save any cats.
II. Dihybrid cross.
A. This time select genes W, B, and A but make both parents heterozygous for W and B
and homozygous for aa . The genotype is Ww Bb aa.
7. What is the phenotype or color of both parents?
B. Produce a litter of kittens.
C. In the kittens the brown color will appear if you produce several litters.
8. What is the genotype of the brown kittens?
9. The probability of a brown kitten is 1/16. How does the number of your brown
kittens compare with this prediction?
10. Make a Punnett square to predict this cross: WwBb X WwBb
North Carolina School of Science & Mathematics (catgen 2)
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QUESTIONS
GENE INTERACTION
1. What color are kittens 3 - 10?
2. What genotype are kittens 3 - 10 ?
3. How many kittens are black in 11 - 18?
4. How many kittens are black in 19 - 26?
5. Out of kittens 11 - 26, what percent are black? (This is the number of black kittens
divided by 16.).
6. In order to be a black cat, what genotype must the W’s have?
II. DIHYBRID CROSS
7. What is the phenotype or color of both parents?
8. What is the genotype of the brown kittens?
9. The probability of a brown kitten is 1/16. How does the number of your brown
kittens compare with this prediction?
10. Make a Punnett square to predict this cross: WwBb X WwBb
North Carolina School of Science & Mathematics (catgen 2)
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North Carolina School of Science & Mathematics (catgen 2)
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