Linked Genes

Who used fruit flies to demonstrate that genes are located on chromosomes?

• Watson and Crick

• Gregor Mendel

• Charles Darwin

• Thomas Hunt Morgan

What phenomenon describes the exchange of genes between chromosomes?

• Crossing over

• Mutation

• Transcription

• Gene expression

What did Morgan observe in his genetic crosses that was unexpected?

• All genes were recessive

• More parental than recombinant phenotypes

• Equal parental and recombinant phenotypes

• High mutation rates

What does a 17% recombination frequency imply about the genes in Morgan's study?

• They assort independently

• They are closely linked on the same chromosome

• They are on different chromosomes

• They are not linked

How do modern scientists determine the location of genes?

• Observing phenotypes

• Using Punnett squares

• Through breeding experiments

• By sequencing DNA