Genetics Vocabulary: Key Terms in Inheritance and Variation

How many pairs of chromosomes do humans typically have?

• 22 pairs

• 24 pairs

• 21 pairs

• 23 pairs

What are chromosomes primarily composed of?

• RNA

• Carbohydrates

• DNA and proteins

• Proteins only

What does a segment of DNA that codes for a specific trait represent?

• An allele

• A protein

• A chromosome

• A gene

What term describes different versions of a gene?

• Protein

• DNA

• Chromosome

• Allele

What is the term for the actual genetic composition of an organism?

• Phenotype

• Gene

• Genotype

• Allele

If an organism has one dominant and one recessive allele, what is likely its phenotype?

• Recessive

• Mixed

• Dominant

• Neutral

Which genotype would express a recessive trait?

• Heterozygous

• Homozygous dominant

• Homozygous recessive

• Both alleles dominant

What does 'homozygous' mean in genetic terms?

• Recessive alleles

• Different alleles

• Same alleles

• Dominant alleles

What does 'heterozygous' refer to in genetics?

• Same alleles

• Different alleles

• Only dominant alleles

• No alleles

Which scenario describes a heterozygous genotype?

• No alleles present

• Two recessive alleles

• Two dominant alleles

• One dominant and one recessive allele