Exam 9: The Locations of Genes on Chromosomes: Linkage and Genetic Maps

The maximum map distance that can be observed in a cross concerning two loci is ___ map units.

In an experiment, two homologous chromosomes with alleles as shown below (original homologous chromosomes) underwent meiosis and to product four chromosomes (resultant chromosomes). How many crossovers appear to have occurred during meiosis?

Genes that are located close together on a homologous chromosome are more likely to be inherited together than genes that are further apart.

A Drosophila parent fly heterozygous for alleles for black body, dumpy wings, and purple eyes was test-crossed to a fly that was homozygous recessive for all three genes. The genes are all on the same chromosome. The offspring had the following phenotypes in the following numbers: Phenotype Number of offspring wild type 225 black body, purple eyes, dumpy wings 238 dumpy wings 122 black body, purple eyes 135 black body, dumpy wings 15 purple eyes 19 purple eyes, dumpy wings 6 black body 5 What were the genotypes of the chromosomes in the parent? Please select all that apply.

Match the missing words in the following phrase. Genes are [A] if they are on the same chromosome and are [B] if they are on different chromosomes. Genes that are on different chromosomes segregate [C] at meiosis whereas genes on the same chromosome are more frequently inherited [D].