A genetics instructor designs a laboratory experiment to study the effects of UV radiation on mutation in bacteria. In the experiment, the students spread bacteria on petri plates, expose the plates to UV light for different lengths of time, place the plates in an incubator for 48 hours, and then count the number of colonies that appear on each plate. The bacteria that have received more UV radiation should have more pyrimidine dimers, which block replication; thus, fewer colonies should appear on the plates exposed to UV light for longer periods. Before the students carry out the experiment, the instructor warns them that while the bacteria are in the incubator, the students must not open the incubator door unless the room is darkened. Why should the bacteria not be exposed to light?
Genetic Recombination
Recombination is crucial to this process because it allows genes to be reassorted into diverse combinations. Genetic recombination is the process of combining genetic components from two different origins into a single unit. In prokaryotes, genetic recombination takes place by the unilateral transfer of deoxyribonucleic acid. It includes transduction, transformation, and conjugation. The genetic exchange occurring between homologous deoxyribonucleic acid sequences (DNA) from two different sources is termed general recombination. For this to happen, an identical sequence of the two recombining molecules is required. The process of genetic exchange which occurs in eukaryotes during sexual reproduction such as meiosis is an example of this type of genetic recombination.
Microbial Genetics
Genes are the functional units of heredity. They transfer characteristic information from parents to the offspring.
A genetics instructor designs a laboratory experiment to study the effects
of UV radiation on mutation in bacteria. In the experiment, the students
spread bacteria on petri plates, expose the plates to UV light for different
lengths of time, place the plates in an incubator for 48 hours, and then
count the number of colonies that appear on each plate. The bacteria that
have received more UV radiation should have more pyrimidine dimers,
which block replication; thus, fewer colonies should appear on the plates
exposed to UV light for longer periods. Before the students carry out the
experiment, the instructor warns them that while the bacteria are in the
incubator, the students must not open the incubator door unless the room
is darkened. Why should the bacteria not be exposed to light?
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
