A wild-type culture of yeast is exposed to the mutagen ethyl methanesulfonate (EMS). Yeast cells are plated on a complete medium, and 6 colonies are transferred to a new complete medium plate for further study. Seven replica plates are made from the complete medium plate to plates containing minimal medium or minimal medium plus one or two amino acid with the following results. Determine which colonies are prototrophic (wild-type), auxotrophic for one amino acid, or auxotrophic for more than one amino acid.

New york city has 2,181 inhabitants per square mile. the state of alaska has 1.03 inhabitants per square mile. ecologists would say alaska has a low exponential growth population density birth rate carrying capacity

Imagine that certain laws of physics could be ignored and you were able to travel vast distances in moments. now imagine that you traveled to an earth-like planet located light-years away that is known to support life. think about what you’ve learned in this unit and make an argument for what you think would be the dominant type of life form on this planet. consider whether a notochord is required for an organism to manipulate its environment and become a dominant creature.

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.