GENETICS L12

Question 1

gene

Answer 1

• unit of hereditary information

Question 2

allele

Answer 2

• alternative version of a gene

Question 3

character

Answer 3

• observable, heritable feature

Question 4

trait

Answer 4

• detectable variant of a character

Question 5

genotype

Answer 5

• genetic makeup

- what alleles are present

Question 6

phenotype

Answer 6

• observable physical traits

Question 7

true breeding

Answer 7

• always express same trait after self fertilization
• no exceptions
• all express same phenotype

Question 8

blending inheritance hypothesis

Answer 8

• gametes contain sampling of fluids from parents bodies
• fuse during reproduction
• fluids blend, offspring is intermediate

Question 9

P generation

Answer 9

• parental generation

Question 10

F1 generation

Answer 10

• 1st filial generation

Question 11

F2 generation

Answer 11

• 2nd filial generation

Question 12

conclusions of Mendel’s experiments

Answer 12

• no intermediate phenotypes appeared
• lost phenotypes reappear
• REJECTED

Question 13

4 components of Mendel’s model

Answer 13

• alleles
• 2 factors for each character
• dominance
• 2 principles of heredity

Question 14

2 factors for each character

Answer 14

• diploid individuals inherit 2 copies of each gene
• 1 from each parent
• may be identical (true breeding lines), may be different
• found on homologous chromosomes

Question 15

dominance

Answer 15

• if two alleles differ:
• • dominant allele determines phenotype
• • recessive allele has no noticeable effect on phenotype

Question 16

law of segregation

Answer 16

• 2 alleles for a character segregate during gamete formation - each gamete only gets 1

Question 17

law of independent assortment

Answer 17

• genes on different chromosomes assort independently during gamete formation
• due to random orientation of tetrads during metaphase 1

Question 18

genetic recombination

Answer 18

• new combination of alleles in offspring

Question 19

monohybrid

Answer 19

• heterozygous for one character

- cross between heterozygotes

Question 20

monohybrid test cross

Answer 20

• used to identify genotype of individual with dominant phenotype

Question 21

dihybrid cross

Answer 21

• individual heterozygous for 2 traits

Question 22

dihybrid test cross

Answer 22

• determine if 2 traits are linked

Question 23

multiplication rule

Answer 23

allows for the prediction of combined probabilities of independent events
- occurrence of one does not affect probability that other will occur

Question 24

addition rule

Answer 24

• predicts combined probabilities of mutually exclusive events