Human Genetics Pt.2

What are multiple alleles?

genes with more than 2 possible versions

what gene system is an example of multiple alleles?

the ABO blood system type

Which blood type shows codominant

type AB

What does Rh+ mean? 

a person produces an Rh antigen that supports immunity

On which chromosomes are sex-linked

X and Y chromosomes

Why are males more likely to have X-linked disorders?

because they only have one X chromosome, so a single recessive allele will show the trait

What are examples of sex-linked traits?

colorblindness and hemphilia

What does “genetic susceptibility” mean? 

inheriting genes that make you more likely to develop a trait or condition under certain environment conditions

What causes cavities to form?

Bacteria ferment sugars into lactic acid, which damages enamel.

What is a mutation?

A change in the DNA sequence.

What can mutations cause?

Changes in phenotype — sometimes beneficial, neutral, or harmful.

What are mutagenic agents?

Substances that increase the rate of mutations (e.g., chemicals, radiation, nicotine).

What does a lethal mutation do?

Prevents an organism from surviving or reproducing

What is a non-lethal mutation?

A mutation that changes a trait (like pigment) but doesn’t kill the organism.