Mendelion Genetics

Question 0

Gregor Mendel (1866)

Answer 0

Developed inheritance by genes + alleles

Experimented with peas

Question 1

Genetics

Answer 1

Study of inherited characteristics + how they’re transmitted between generations

Question 2

Thomas Hunt Morgan

Answer 2

Experimented with drosophila fruit flies

Identified genes in chromosomes

Question 3

Homologous chromosomes

Answer 3

A pair of chromosomes with similar genes

2 of each gene, 1 from each parent

Question 4

Locus

Answer 4

Location of gene on chromosome

Question 5

Alleles

Answer 5

Specific form of a particular gene
2 diff alleles for most genes
2 alleles in homologous pair of chromosomes, alleles can be the same or diff

Question 6

Homozygous

Answer 6

If the pair of alleles is similar, then this allele is always expressed

Question 7

Heterozygous

Answer 7

If the pair of alleles is different, then only one allele is expressed, the other allele is not expressed or used

Question 8

Dominant allele

Answer 8

Expressed if heterozygous, also if homozygous

Question 9

Recessive allele

Answer 9

Not expressed or used if heterozygous, only expressed if homozygous

Question 10

Notation

Answer 10

Capital letter for dominant allele
Lower-case letter for recessive allele
List the dominant allele first

Question 11

Genotype

Answer 11

The list of the 2 alleles present

Eg: AA, Aa, aa

Question 12

Phenotype

Answer 12

The result, outcome, or physical appearance of the genotype

Question 13

Punnett squares

Answer 13

Method to predict probabilities of offsprings

Question 14

Mono hybrid cross

Answer 14

2X2 grid for a single gene
Cross between heterozygous
Genotype ratio = 1:2:1
Phenotype ratio = 3:1

Question 15

Trihybrid cross

Answer 15

8X8 grid for 3 separate genes

Question 16

Dihybrid cross

Answer 16

4X4 grid for 2 separate genes
(On 2 separate pairs of chromosomes = not linked)
Cross between heterozygous
Phenotype ratio = 9:3:3:1

Question 17

P generation

Answer 17

Parent

True-breeding if homozygous genotype, produces uniform offsprings

Question 18

F1

Answer 18

“Filial one” or first generation

Question 19

F2

Answer 19

Second generation

Question 20

Test cross

Answer 20

Experiment to reveal dominant organism

Question 21

Complications

Answer 21

Not all genes with complete dominance (with two alleles where one is clearly dominant over the other)

Question 22

Co dominance

Answer 22

Alleles neither dominant or recessive, heterozygote uses both alleles
Eg: sickle-cell trait (heterozygous)

Question 23

Incomplete dominance

Answer 23

Dominant vs recessive not clear-cut, heterozygote uses dominant half-way
Eg: red X white = pink flowers

Question 24

Multiple alleles

Answer 24

More than 2 diff alleles for a single gene