Q1. Conjunction mapping could be used to locate genes on a bacterial chromosome. In this example, F+ strain is able to synthesize methionine, valine, leucine, and histidine. The F- strain is unable to synthesize these amino acids; therefore, they should be supplied in the growth medium. Use the results from replica-plating to answer the questions.

1. On which media, if any, must the F+ be able to grow? The F-?

2. Recognize the prototrophs and auxotrophs. How can you advise?

3. Can you map the chromosome of this species? What further information do you need?

Q2. The seeds of orchids are among the smallest known, with virtually no endosperm and with miniscule seed leaves. As a result, what must one expect to be true of such seeds?