Topic 8

Question 1

what is the foundation of modern genetics

Answer 1

Mendalian genetics

Question 2

short description of the so-called “classic” genetics

Answer 2

mendel’s laws: inheritance of qualitative traits

- segregation of traits during crosses produce free and independant combos

Question 3

alleles; what are they, and some characteristics

Answer 3

variant form of a gene
aka single major genes = monogenic traits
- envoironmental factors rarely influence the phenotype
- traits are either present or not

Question 4

name the (3) terminalogy for the different generations

Answer 4

1 - P (parent)
2 - F1 (first generation)
3 - F2 (second generation)

Question 5

name three crosses

Answer 5

1 - Monohybrid: 2 purebred strains (homozygote) differ in a sigle trait based on the Law of Segregation (1st law)
2 - Reciprocal cross: an expreimental cross to see wether a trait is sex linked or not
3 - dihybrid cross: cross of two homozygotes that differ in two traits

Question 6

define genotype and phenotype

Answer 6

phenotype: ind appaerance for a trait
genotype: pair of alleles carried by an induvidual at a particular locus

Question 7

difference btw homozygote and heterozygote

Answer 7

AA aa Aa

genotype where both alleles are the same or differentt

Question 8

dominant and recessive genes

Answer 8

one copy of an allele is enough to express phenotype, or two copies are needed(recessive)

Question 9

genetic polymorphism

Answer 9

more than two alleles identified in a population

Question 10

dominance in alleles (3)

Answer 10

1 - semidominance: aka incomplete dominance; both alleles expressed to a certain degree
2 - codominance: both alleles equally expressed
3 - overdominance: heterozytes are more fit than homozygotes

Question 11

Mendels law’s

Answer 11

law of segregation
law of uniformity and reciprocity
law of independant assortment

Question 12

describe parts of the law of segregation

Answer 12

separating chromosomes into the gametes

- 2 alleles for each characteristics - one from each parent = variation (mix of maternal and paternal alleles)

Question 13

describe the law of uniformity and reciprocity

Answer 13

homozygote F1 = F1 have identical gneo/phenotype (ind of which is recessive/dominant) UNIFORM offspring

heterozygote F1 = P characteristics reappear in F2 -> NOT UNIFORM

Question 14

describe the law of independant assortment

Answer 14

genes are assorted independantly of eachother into gametes = inheritance patterns will not affect eachother