Inheritance

Question 1

Gene

Answer 1

sequence of bases on a DNA strand that codes for a specific polypeptide

Question 2

genotype

Answer 2

the complete set of alleles for the organism’s genome

Question 3

phenotype

Answer 3

the set of observable/measurable characteristics of an organism, resulting from the expression of the genotype and its interaction with the environment

Question 4

dominant allele

Answer 4

if present in enotype, will always be expressed in the phenotype

Question 5

recessive allele

Answer 5

only expressed in he phenotype when no dominant allele present, i.e. homoxygous recessive

Question 6

codominant alleles

Answer 6

if both present in genotype, both expressed in phenotype

Question 7

monohybrid inheritance

Answer 7

inheritance of a single pair of alleles that code for a single phenotypic characteristic

Question 8

ratio when two heterozygous individuals crossed in monohybrid inheritance

Answer 8

3:1

Question 9

non-linked dihybrid inheritence

Answer 9

alleles of each gene located on separate pairs of homologous chromosomes

Question 10

dihybrid inheritance

Answer 10

inheritance of 2 pairs of alleles which may code for 2 different phenotypic characteristics or only 1 characteristic

Question 11

epistasis

Answer 11

the expression of one gene is inhibited or supressed by the expression of another gene

Question 12

how would a heterozygous individual’s genotype be written using the letters N, n, R and r?

Answer 12

NnRr

Question 13

wht is the phenotypic ratio in dihybrid inheritance when two individuals, heterozygous for both characteristics, are crossed?

Answer 13

9:3:3:1

Question 14

dihybrid linked

Answer 14

alleles coding for each characteristic are located of the same pair of homologous chromosomes

Question 15

how to tell if inheritance is linked or non-linked based on phenotypic ratios? (2 things)

Answer 15

1. linked will always have unepected results
2. linked will have a 3:1 ratio, ignorig rare phenotypes, while non-linked will have 9:3:3:1

Question 15

why does llinked inheritacne produce unexpected results?

Answer 15

crossing over occurs in prophase I of meiosis resulting in recombinant gametes

Question 16

when crossing over more likely to occur (in relation to chromosomes)?

Answer 16

on longer chromososmes or if alleles are further apart on the same chromosome

Question 17

sex linked inheritance

Answer 17

inheritance of alleles located on the sex-chromosomes

Question 18

sex-linked characteristic

Answer 18

phenotypic characteristic inherited along with the individul’s sex (dihybrid)

Question 19

2 advantages of chi-squared

Answer 19

1. don’t need to take measurements
2. used for categorical, discrete data (like genetypes)

Question 20

why is chi-squred used in genetics? (3 things)

Answer 20

1. have distinct genotypes
2. can count frequencies
3. can predict the outcomes