Understanding Genetics Through Punnett Squares

What is a Punnett Square used for in genetics?

• To measure the size of cells

• To predict the probability of offspring inheriting certain traits

• To observe chromosomes under a microscope

• To determine the age of fossils

Which term describes the genetic makeup of an organism?

• Phenotype

• Genotype

• Chromosome

• Allele

What does the term "phenotype" refer to?

• The physical appearance of a trait

• The genetic code for a trait

• The number of chromosomes

• The process of cell division

Which of the following is an example of a homozygous genotype?

• Aa

• AA

• Ab

• aB

If an organism has two different alleles for a trait, it is called:

• Homozygous

• Heterozygous

• Dominant

• Recessive

In a Punnett Square, what do the letters inside the boxes represent?

• The possible genotypes of the offspring

• The number of chromosomes

• The parents' ages

• The environment

If a parent has genotype Aa and another parent has genotype aa, what are the possible genotypes of their offspring?

• Only AA

• Only aa

• Aa and aa

• Only Aa

Which of the following best describes a heterozygous genotype?

• Both alleles are the same

• Both alleles are different

• Only one allele is present

• No alleles are present

A Punnett Square shows a cross between two parents with genotypes Aa and Aa. What is the probability that their offspring will have the genotype aa?

If a trait is dominant, what must be true for an organism to show the dominant phenotype?

• It must have two recessive alleles

• It must have at least one dominant allele

• It must have no alleles

• It must have two dominant alleles only