Which of the following is a true statement?

a. falling sea levels and colliding continents created connections between continents that led to great movements of land animals during the neogene period.
b. during the quarternary period, the earth heated up.
c. the first whales evolved during the quarternary period
.d. land mammals such as bats, cats, dogs, cattle and mammoths became common during the neogene period.

Which statement describes john tuzo wilson’s contribution to the theory of plate tectonics?

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.

Study the picture of the ocean. which is the best example of an organism’s niche shown in the picture? a. the environment contains several of the same species of coral. b. the shallow area of the ocean meets the needs of the coral and the fish. c. the ocean has fish and coral that live in the same area. d. the coral take in food from the water and provide shelter for the fish.