Lab 15:Human Mendelian genetics

Question 1

A heritable feature of an organism that varies among individuals, features such as flower color in Mendel’s peas or freckles in humans.

Answer 1

Character

Question 2

A variety or state of a character, such as a white flower color in peas or no freckles on a human.

Answer 2

Trait

Question 3

The functional unit of heredity. It is found at particular locations on the chromosome, and the nucleotide sequence determines the primary structure of all polypeptides and proteins.

Answer 3

Structural gene

Question 4

An alternative form of a gene which occurs at the same location on homologous chromosomes.

Answer 4

Allele

Question 5

The actual alleles present for a given gene homologous chromosomes. Expressed in letters.

Answer 5

Genotype

Question 6

The outward expression of a genotype, or what the trait looks like externally, or physically.

Answer 6

Phenotype

Question 7

A genotype with the same alleles for a gene on homologous chromosomes.

Answer 7

Homozygous

Question 8

A genotype with different alleles for a gene on homologous chromosomes.

Answer 8

Heterozygous

Question 9

The allele expressed in a phenotype when a genotype is heterozygous.

Answer 9

Dominant allele

Question 10

The allele not expressed in the phenotype when the genotype is heterozygous. Only expressed when the genotype is homozygous.

Answer 10

Recessive allele

Question 11

A genetic condition which occurs when neither allele is dominant over another, but both are expressed in the phenotype.

Answer 11

Codominant