Exam 2 examples

Question 1

Indep assortment vs Chromosomal Theory

Answer 1

purple, long pollen pea plant vs red, short pollen pea plant do not have 9:3:3:1 ratio of indep assortment

Question 2

Notation for crosses with linkage

Answer 2

two traits from one parent on one side of line and two traits from other on other side. Traits match up vertically ex:
A B
a b

Question 3

multiple crossovers

Answer 3

double cross: 0% detectable recomb

triple cross: 50% detectable recomb

quadruple cross: 100% detectable recomb

Question 4

lod score

Answer 4

log (prob of obs from linked : prob of obs from indep assort)

• lod > 3 = linkage

Question 5

mapping bacterial genes with interrupted conjugation

Answer 5

transfer time = order and distances

Question 6

gene mapping with transformation

Answer 6

If genes a and b are
frequently cotransformed, and genes b and c are frequently
cotransformed, but genes a and c are rarely cotransformed,
then gene b must be between a and c
= a b c (recomb %)

Question 7

conjugation

Answer 7

Lederberg and Tatum exper
- F+: donor with F factor - F-: recipient lacking f factor
- Hfr cells (High-frequency recombination): donor cells with F factor integrated into the donor bacterial chromosome
- F’ cells: F plasmid carrying some bacterial genes
- Merozygotes: partial diploid bacterial cells containing F plasmid carrying some bacterial genes

Question 8

virus: complementation test

Answer 8

if in diff cistrons (segments of DNA)(ie far apart), complementation happens and proteins produced

Question 9

• Meleson and Stahl’s Experiment

Answer 9

heavy medium: one heavy band (original DNA)
lighter medium: one middle band (1 parental and 1 new)
even lighter medium: one light band and one medium band (original DNA and DNA with one parental and one mutant)
* Proves semiconservative theory

Question 10

Heinz
Fraenkel-Conrat and Bea Singer experiment

Answer 10

2 types of RNA coated with the other type’s proteins. Infect tobacco leaf. RNA with its original proteins recovered.

Question 11

replicative transposition with 1 ele

Answer 11

2 circular DNA molecs form together with the ele on either end. crossing over at ele. two sep

Question 12

replicative transposition with 2 ele

Answer 12

2 eles link up to form 1 oval RNA molec. replicate. cross over. sep 1 with 1 ele and 1 with 2 ele