Exam 1

Question 1

What is the law of segregation?

Answer 1

-parents have pair of alleles for particular traits -equal likelihood a parent passes on one trait or the other to a gamete

Question 2

What is the law of independent assortment?

Answer 2

-different pairs of alleles for different traits are passed on independently of each other

Question 3

Blending Inheritance vs. particulate inheritance.

Answer 3

Particulate inheritance: Mendel’s presumption. Blending inheritance: two different alleles would mix in the F1 generation to form an intermediate phenotype.

Question 4

If you are performing a dihybrid cross for pea plant color (green, yellow) and shape (round, wrinkled)

how can you determine the following cross?

RrGg x RrGg

Answer 4

“forked line method”

multiply the probabilities because they’re independent. (like Bayes theorem!)

Question 5

How do you determine the number of possible genotypes given a di, tri, tetrahybrid (etc.) cross?

Answer 5

Number of possible genotypes is 2^n

where n is the number of genes

Question 6

What is the p-value in a Chi-square test? What is represented by a p-value of 0.05?

Answer 6

A p-value of 0.05 or less says that the probability of obtaining the given result by chance is less than 5%. By convention, when an experimental result has less than a 5% probability, the hypothesis of chance is rejected. P-values greater than 0.05 represent a non-significant deviation between observed and expected.

Question 7

Where in meiosis does independent assortment occur?

Answer 7

Metaphase I of Meiosis (homologous chromosomes line up along the equator on either side, it’s random)

Question 8

What is the result of Meiosis I?

Answer 8

Two haploid cells with sister chromatids

Question 9

What is true of the graph of the chi-square distribution?

Answer 9

• non-negative

not symmetric

• skewed right
• area under the curve= 1
• 0 to infinity

df= (#rows-1)*(#col-1)

Question 10

How do you calculate RF?

Answer 10

RF= (R+R)/ Total Prog

Question 11

How do calculate expected recombinant progeny?

Answer 11

E(R)= RF* number of progeny/2= number per recombination class (2 classes in flygene simulation)

Question 12

What is coefficient of coincidence?

Answer 12

C.O.C= dco observed/ dco expected

Question 13

How do you calculate the expected frequency of double recombinants?

Answer 13

multiply the frequency of recombinants independently

Question 14

What is interference?

Answer 14

1- C.O.C