How do I determine which band to cut out in agarose gel?

What is thought to have caused the mass extinction at the end of the cretaceous period?

Which of the following types of rock would most likely contain a fossil? slate granite lava rock limestone

Agene pool: a) is the collection of all the alleles found in a single species b) is the collection of all the alleles found in a single population c) is the collection of all the chromosomes found in a single population d) is the collection of genes in a species that allow the individuals to swim