Mendelian Genetics definitions

Question 1

allele

Answer 1

alternate forms of a gene

Question 2

loci

Answer 2

the location of the gene on the chromosome

Question 3

genotype

Answer 3

the combination of alleles for a trait (letter code)

Question 4

phenotype

Answer 4

the physical appearance of a trait based in genotype (ratios)

Question 5

dominant

Answer 5

the form of a trait that will always appear when an individual has an allele for it. RR Rr

Question 6

recessive

Answer 6

the form of a trait that will only appear in the individual has 2 alleles for it

Question 7

homozygous

Answer 7

describes the genotype of an individual with two alleles that are the same RR rr

Question 8

heterozygous

Answer 8

describes the genotype of an individual with two alleles for the same gene that are different Rr

Question 9

principle of dominance

Answer 9

when individuals of contrasting traits are crossed, the offspring express only one dominant trait

Question 10

law of segregation

Answer 10

the two alleles (1 from mom and 1 from dad) separate independently into gametes during meiosis

Question 11

punnett square

Answer 11

a chart used to show possible combinations of allele in offspring

Question 12

monohybrid cross

Answer 12

a cross where only one trait is being tested

Question 13

dihybrid cross

Answer 13

a cross where two traits are being tested

Question 14

autosomal inheritance

Answer 14

inheritance of traits from genes located on the autosomes 1-22

Question 15

autosomal dominance

Answer 15

occurs when the disease-causing allele is dominant and the individual has one or both copies of the allele HH or Hh

Question 16

autosomal recessive

Answer 16

occurs when the disease-causing allele is recessive and an individual has both copies of the allele hh