Ch 3: Basic Principles of Heredity (Bio 375)

Question 1

Mendel

Answer 1

theory of particulate inheritance determined using monohybrid crosses (with P, F1, and F2 generations)

Question 2

P (parental) generation

Answer 2

first generation of a cross

Question 3

F1 (filial 1) generation

Answer 3

offspring from parents in P generation

Question 4

F2 (filial 2) generation

Answer 4

second generation of offspring from F1 parents

Question 5

principle of segregation

Answer 5

each diploid individual possesses two alleles for a specific characteristic; two alleles segregate into gametes in equal proportions during gamete formation

Question 6

concept of dominance

Answer 6

when two different alleles are present in a genotype only the dominant allele is expressed

Question 7

dominant

Answer 7

phenotype expressed in heterozygote

Question 8

recessive

Answer 8

phenotype not expressed in heterozygote

Question 9

homozygote

Answer 9

individual organism possessing 2 of the same alleles at a locus

Question 10

heterozygote

Answer 10

individual organism possessing 2 different alleles at a locus

Question 11

monohybrid cross

Answer 11

parents differed in a single characteristic; mating of individuals that are heterozygous at a single locus (Rr x Rr)

Question 12

dihybrid cross

Answer 12

mating of individuals that are heterozygous at two loci (RrYy x RrYy)

Question 13

backcross

Answer 13

mating an individual with a direct ancestor; usually an offspring with its parent

Question 14

reciprocal cross

Answer 14

crosses in which phenotypes and/or genotypes of male and female parents are reversed

Question 15

test cross

Answer 15

cross of an individual which has dominant phenotype but unknown genotype with a homozygous recessive individual to determine genotype of unknown individual

Question 16

multiplication rule

Answer 16

probability of two or more independent results occurring together is calculated by multiplying their independent probabilities

Question 17

addition rule

Answer 17

probability of two or more mutually exclusive outcomes occurring is calculated by adding the probabilities of mutually exclusive outcomes to one another

Question 18

binomial theorem

Answer 18

can be used to determine probability of an outcome that is possible in different orders; accounts for different orders of same outcome

Question 19

binomial formula

Answer 19

n! / (s! t!) * p^s q^t [n = total number of events, s = number of event A, t = number of event B, p = probability of event A, q = probability of event B]

Question 20

principles of independent assortment

Answer 20

alleles at different loci segregate into gametes independently of each other

Question 21

branch diagram

Answer 21

Can obtain both genotypic and phenotypic ratios; By setting out the proportions of genotypes or phenotypes for each allele pair and connecting these to proportions of the other allele pairs, a branch or web of genotypes or phenotypes can be constructed

Question 22

expected ratios in offspring

Answer 22

3:1 phenotypic in monohybrid crosses; 9:3:3:1 phenotypic in dihybrid crosses

Question 23

chi-square test

Answer 23

statistical test to determine if two values are significantly different from each other; determines if the difference between the expected and observed is due to sampling error or a different factor

Question 24

chi-square test formula

Answer 24

sum of (observed-expected)^2/expected

Question 25

chi-square test process

Answer 25

1. determine the chi-square value… 2. determine the probability associated with the value and compare to calculated value with a theoretical table value… 3. compare to the p value threshold… 4. base conclusions on results of statistical test

Question 26

p value

Answer 26

measure of probability that differences between observed and expected are due to random chance

Question 27

threshold for significant difference

Answer 27

p = 0.05