Genes and Alleles

What does PTC stand for?

• A chemical used in genetic classes

• A type of taste bud

• A paper manufacturing company

• A type of genetic marker

Why is PTC paper used in genetic classes?

• To test paper quality

• To teach about paper recycling

• To demonstrate chemical reactions

• To illustrate genetic traits

What determines the ability to taste PTC?

• The temperature of the paper

• Genetics

• Your age

• The type of food you eat

How many chromosomes do humans have?

• 12

• 46

• 23

• 92

What is an allele?

• A kind of protein

• A variant of a gene

• A DNA sequence

• A type of chromosome

What does a dominant allele mean?

• It is always recessive

• It is not expressed

• It is expressed if present

• It can never be inherited

What genotype combination allows a person to taste PTC?

• Tt

• Both TT and Tt

• tt

• TT

If both parents can taste PTC, what is their likely genotype?

• TT

• Tt for both parents

• Tt

• tt

What is a phenotype?

• A genetic makeup

• A physical characteristic

• A type of allele

• A chromosome pair

Is the dominant trait always more common in a population?

• Only in animals

• Yes, always

• No, not always

• Only in humans