Chapter 9: Classical Genetics

Question 1

Gregor Mendel

Answer 1

the father of modern genetics

produced three laws: dominance, segregation and independent assortment

Question 2

law of dominance

Answer 2

2 organisms that are homozygous to 2 opposing traits will produce a hybrid that will exhibit only the dominant trait

Question 3

law of segregation

Answer 3

during the formation of gametes, two traits carried by each parent separate

Question 4

phenotype

Answer 4

what the organism looks like

Question 5

genotype

Answer 5

the genes (alleles)

Question 6

backcross/testcross

Answer 6

determine whether an individual organism showing the dominant trait is homozygous or heterozygous
crossed with a recessive individual

Question 7

law of independent assortment

when does this apply?

Answer 7

genes for one trait are not inherited along genes for another trait
applies when it is a cross between 2 individuals that are hybrid for two traits on separate chromosomes

Question 8

incomplete dominance

Answer 8

blending

uses different capital letters

Question 9

codominance

Answer 9

both traits are shown

(ex. AB blood type)

Question 10

multiple alleles

Answer 10

more than 2 allelic forms of a gene (ex. blood type)

Question 11

polygenic inheritance

Answer 11

blending of several separate genes

Question 12

sex-linked genes

Answer 12

usually a recessive mutation on the X chromosome

carriers: 1 mutated X-linked gene

Question 13

sex-influenced inheritance

Answer 13

due to what gender you are

ex. baldness

Question 14

karyotype

Answer 14

analyses chromosomes

Question 15

pedigree

Answer 15

family tree → indicates phenotype of one trait
female → circle
male → square 
shaded shape → mutation
half-shaded → carrier

Question 16

gene mutation

Answer 16

change in DNA sequence

Question 17

chromosome mutation

Answer 17

deletion
inversion
translocation
polyploidy
nondisjunction

Question 18

nondisjunction

Answer 18

homologous chromosomes fail to separate during meiosis

Question 19

aneuplodiy

Answer 19

abnormal chromosome condition

Question 20

trisomy

Answer 20

chromosome is present in triplicate

Question 21

polypoid

Answer 21

more than 3 sets of chromosomes