Genotypes & Phenotypes

Question 1

Dominant

Answer 1

expresses its trait even when paired with a different allele (the recessive allele).

Question 2

Recessive

Answer 2

only expresses its trait when paired with another identical recessive allele.

Question 3

Carrier

Answer 3

a person who has a gene variant for a recessive disorder but does not show symptoms

Question 4

Homozygous

Answer 4

an organism that has inherited two identical alleles of a particular gene, one from each parent.

Question 5

Heterozygous

Answer 5

having inherited two different alleles, of a gene from each parent

Question 6

Genotype

Answer 6

the specific combination of alleles

Question 7

Phenotype

Answer 7

the expressed characteristic

Question 8

Complete dominance

Answer 8

a dominant allele completely masks the effect of a recessive allele in a heterozygous individual, resulting in the dominant trait being expressed in the phenotype

Question 9

Codominance

Answer 9

both alleles are expressed in the phenotype rather than one being dominant over the other

Question 10

Incomplete dominance

Answer 10

neither allele for a trait is fully dominant, leading to a heterozygous phenotype that is an intermediate blend of the two parental traits

eg. crossing a red snapdragon flower with a white snapdragon flower produces a pink snapdragon flower. This results in three distinct phenotypes (e.g., red, pink, and white) rather than the two typically seen in Mendelian complete dominance.

Question 11

Sex-linked

Answer 11

traits that are influenced by genes located on the sex chromosomes

most are present on the x chromosome
Sex-linked traits are more common in males than females because males have only one X chromosome, while females have two