chapter 9- genetics

Question 1

what are genes

Answer 1

dna nucleotide sequence that codes for traits

Question 2

specific version of a gene

Answer 2

allele

Question 3

alleles for a trait

Answer 3

genotype

Question 4

physical expression of alleles (of genotype)

Answer 4

phenotype

Question 5

• alleles/ genes segregate during meiosis

-gametes carry only 1 allele for a trait

Answer 5

law of separation

Question 6

alleles for different traits sort out independently during meiosis (meaning alleles are not linked)

Answer 6

law of independent assortment

Question 7

what is the F2 phenotypic ratio for monohybrid mendelian cross

Answer 7

3:1

Question 8

what is the F2 phenotypic ratio for dihybrid mendelian cross

Answer 8

9:3:3:1

Question 9

monohybrid cross

Answer 9

1 trait

Question 10

dihybrid cross

Answer 10

2 traits

Question 11

what is the reason for performing a test cross

Answer 11

cross dominant with recessive and examine offspring. if all offspring have dominant trait, then the unknown genotype is homozygous. if 50% of offspring have dominant, then unknown genotype is heterozygous

Question 12

F1 offspring look intermediate between phenotype of parents. the dominant allele cannot be completely expressed when recessive allele is present

Answer 12

incomplete dominance

Question 13

2 dominant alleles, both equally expressed, separate phenotypes

Answer 13

codominance

Question 14

one gene has many different characteristics = different phenotypes

Answer 14

pleiotrophy

Question 15

many genes have an additive effect on the phenotype = 1 phenotype

many genes code for one trait

Answer 15

polygenic inheritance

Question 16

one gene changes the expression of another gene

one gene depends on another to be expressed

Answer 16

eoistasis

Question 17

physical environmental factors greatly change the phenotype

Answer 17

environmental impacts

Question 18

genes are located on chromosomes and they segregate and assort during meiosis into gametes

Answer 18

chromosome theory of inheritance

Question 19

chromosomes other than sex chromosomes that there are 22 of in humans

Answer 19

autosomes