Mutualism
a. ecological relationship between members of two different species that directly interact with each other.
b. ecological, symbiotic relationship in which one species benefits and another is neither nor harmed.
c. ecological, symbiotic relationship between two species that each benefit from their interaction.
d. ecological, symbiotic relationship in which one organism benefits by harming another.

In fruit flies, gray bodies (g) are dominant over black bodies (g), and brown pigments (n) are dominant over yellow pigments (n). each individual possesses two alleles for each trait. if a fly that is homozygous dominant for both traits is crossed with a fly that is homozygous recessive for both traits, what is the predicted genotype of the offspring.

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

Which of the following statements about protists are true? a.they are typically found in moist environments. b.they are all unicellular. c.they have a nucleus. d.they are all multicellular.