There are little birds that spend a great deal of time on the back of a rhinoceros and eat the blood sucking ticks out of the rhino's ears. Answer the following questions regarding these creatures' relationships. 1) The bird -rhino relationship is an example of: a) parasitism b) mutualism c) predator- pray d) commensalism. 2) The bird-tick relationship is an example of: a) parasitism b) mutualism c) predator- pray d) commensalism. 3) The tick-rhino relationship is an example of: a) parasitism b) mutualism c) predator- pray d) commensalism

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.

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.

What best explains the inability for life to exist in earth early atmosphere