Seismograph station D is 7,700 kilometers from the epicenter. If the P-wave arrived at this station at 2:15 p. m., at approximately what time did the earthquake occur? A) 1:56 p. m.
B) 2:00 p. m.
C) 2:04 p. m.
D) 2:08 p. m.

Why do you think the puppy litter was all dark-haired?

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

Select the correct answer. which mutation is harmful to the organism? a. a mutation allowing moths to camouflage better on blackened tree bark b. a mutation making staphylococcus aureus resistant to the antibiotic methicillin c. a mutation inhibiting human immunodeficiency virus from attaching to and entering the cell d. a mutation causing uncontrolled cell division e. a mutation giving plant leaves a bitter taste to discourage herbivores from eating them