Genetics Exam 1

What happens if you look at more than 2 traits simultaneously

• The alleles for each trait segregate independently AND

• do not influence the inheritance (independent assortment) of the second trait

Forked-line diagram

determines the genotypes and frequencies

Progeny phenotypes

tend to occur in definite ratios based on the initial frequencies

Test Cross

used to verify independent assortment

• display four phenotypes in equal frequencies as expected by application of Mendel’s laws

Conditional Probability

• m The probability of an event (A), given that another (B) has already occurred

Binomial Probability

Predicting one event from many outcomes

the probability that a binomial experiment results in exactly X successes

Rules of Probability theory, Product Rule

1. if two or more events are independent of one another their joint probability is the product of the individual probabilities

Rules of Probability theory, Sum Rule

1. The joint probability of any of two or more mutually exclusive ( not independent ) events is the sum of the probabilities of each event

2. The probability of obtaining any heterozygote is equal to the sum of the probabilities of each possible heterozygote

Binomial Expansion

• Two variables, each representing the frequency of one o flow alternative outcomes

• P(outcome 1) = p; P(outcome 2) = q

• if p and q are the only possible outcomes, p+p=1

• expand the expression by n events; (p+q)ⁿ=1

Pascal’s triangle

1) binomial coefficentbgs (P+g) raised to the nth power where n= # of events

2) each line is total # outcomes (p+q)ⁿ n=2

Binomial Probability Definitions

P = n!/ s! t! (p^sq^t)

• p: probability to get to event x

• q: probability to get to event y

• s: times to get event x

• t: times to get event y

• n: s+t (total events)

Eukaryotic

more complex with membrane bound organelles

Prokaryotic

lack nuclear membrane and typically no membrane bound organelles

Gene

• fundamental unit of heredity

• come in multiple forms called alleles

• determines phenotypes

• defined DNA sequences

Chromosomes

are long molecules of double-stranded DNA and protein, which contains genes

Homologous pairs

carry genes for the same traits

Hereditary flow

DNA → transcription → RNA → translation → protein

nucleic acid structure

• phosphate

  • phosphodiester linkage

• Sugar

  • Ribose or deoxyribose

• Nitrogenous base (hydrogen bonds)

  • Purines

    • Adenine and Guanine

  • Pyrimidines

    • Cytosine and Thymine/Uracil

Chargaffs Rule

percentages of adenine and thymine are equal and the percentages of guanine and cytosine are equal

• complementary base pairs

  • A with T

  • C with G