Biology Exam Iv

Front 1

Laws of Segregation

Back 1

Traits are determined by pair of hereditary factors that separate during gamete formation and rejoin at fertilization

Front 2

Gene

Back 2

section of DNA containing information for a trait

Front 3

Allele

Back 3

symbol for a gene as a letter of the alphabet

Front 4

Multitrait inheritance

Back 4

cross involving more than one trait at a time

Front 5

dihybrid cross

Back 5

crossing of two traits

Front 6

gamete

Back 6

result from Meiosis-- each gamete will contain one allele from each pair of alleles

Front 7

Law of Independant Assortment

Back 7

each member of a pair of homologous chromosomes separates independently of the members of other pairs so the results are random

Front 8

Recessive inheritance

Back 8

Trait is determined by a recessive allele
-heterozygotes are usually unaffected because dominant allele is expressed

Front 9

Dominant Inheritance

Back 9

Determined by a dominant allele
-homozygous recessive is unaffected.

Front 10

Multiple allele Inheritance

Back 10

More tan two alleles for a trait in population (each individual has a pair of alleles)

Front 11

I(a)

Back 11

has polysaccharide A as a marker on membrane of red blood cell

Front 12

I(b)

Back 12

has polysaccharide B as a marker on membrane of red blood cell

Front 13

O Allele = i

Back 13

has neither polysac. A or B on red blood cell

Front 14

Type A blood

Back 14

Two possible genotype
I(a) I(a) or I(a)i
-only polysac. A
-Polysac B is foreign

Front 15

Type B blood

Back 15

I(b)I(b) or I(b)Ii
Polysacc. B on red blood cell membrane
Polysacc A is foreign - person will produce antibodies to it

Front 16

Type AB Blood

Back 16

genotype I(a)I(b)
both A and B polysacc. on membrane
-person doesnt produce antibodies to either

Front 17

Type O Blood

Back 17

ii
Neither A or B polysacc.
-both are foreign so it produces antibodies to both

Front 18

Pleiotopy

Back 18

One pair of alleles determines expressions of one or more trait
Ex. Frizzle trait in chickens

Front 19

Polygenic Inheritance(continuous variation)

Back 19

one trait is determined by more than one pair of alleles
ex. human height, human eye color, color of wheat

Front 20

Multifactorial traits

Back 20

traits controlled by many factors including genetic & invironmental influences.
ex. human skin color

Front 21

Epastasis

Back 21

one pair of alleles modifies or interferes with expression of different pair of alleles
ex. albinism

Front 22

Sex determination

Back 22

Males have XY
Females have XX

Front 23

SRY gene

Back 23

on y chromosome -- Sex determining region on the chromosome
1) produces substances that make fetal gonads sensitive to testosteroe so they become testes rather than ovaries.

Front 24

Sex linked trait

Back 24

nonsexual characteristics controlled by alleles on sex chromosome

Front 25

Transcription

Back 25

process of making RNA using DNA as template

Front 26

tRNA

Back 26

carries amino acid into position as designed by mRNA