Question

Please answer all the questions

A species of scarab beetles have red, orange or golden wing covers. A cross between a pair of orange beetles gave 3/4 offspring orange and 1/4 golden.  A cross between a red and an orange pair have 1/2 red and 1/2 orange offspring. How do you explain these results?  Choose the best answer.  The trait is controlled ….

Select one:

a. by three alleles with incomplete dominance

b. by three alleles with both dominance, incomplete dominance and recessive alleles

c. by three alleles with dominance and recessive relations

d. by two alleles with incomplete dominance

e. by two alleles with dominance and recessive relations

A haploid yeast strain is mutagenized to identify mutants that require supplementation by arginine.  10 mutants are identified and mated to each other to generate diploids for complementation testing.  The test gives the following results

m1 m2 m3 m4 m5 m6 m7 m8 m9 m10

m1        -     -     -    +     +    +   +     +    -     +   

m2              -     -    +     +    +    +    +    -     +

m3                     -    +    +     +   +     +    -     +

m4                           -    +     -    +     +    +    +

m5                                 -      +   +     +   +     +

m6                                        -    +     +    +    +

m7                                              -     +    +    +

m8                                                     -    +    +

m9                                                          -     +

m10                                                               -

Is any strain or are any strains doubly mutant?

Select one:

a. m2

b. m1, m2, m3

c. m1

d. no double mutants

e. m4 and m6

A cross between pure breeding lines of long squash and disk squash produces an F2 generation with fruits of three shapes sorted as follows

disk shaped fruit 271

sphere shaped fruit 173

long shaped fruit                     36

                                                480

The breeder thinks this may represent a 9:6:1 ratio, where there are 2 unlinked genes with 2 alleles. The plants with either gene as a recessive homozygote give sphere shaped fruit, the double homozygous recessive gives long shaped fruit, and any plant with at least one copy of each gene as the dominant allele gives disk shaped fruit.

Calculate the Chi squared statistic to test this hypothesis. Choose the best answer.  The chi-squared value is between:

Select one:

a. 2.01 and 4

b. 1.01 and 2

c. greater than 4

d. 0 and 1

e. -2 and 0

Answer 1

1. Answer: Option C is correct
Explanation:
i. Orange X Orange ---> 3/4 Orange and 1/4 Golden
Aa X Aa ---> AA Aa Aa aa

ii. Red X Orange ---> 3/4 Orange and 1/2 Red
A'A X Aa -----> A'A A'a AA Aa

Dominance order: A' > A > A
A' = Red (A'A' or A'A or A'a)
A = Orange (AA or Aa)
a = Golden yellow (aa)

2. Answer: Option E is correct
Explanation:
Complementation groups from the given experiment:
i. m1 = m2 = m3 = m9
ii. m4 = m6
iii. m5
iv. m7
v. m8