Fleas are commonly seen on the bodies of dogs. these fleas attach themselves to the host and draw blood as nourishment. apart from getting nourishment, fleas also get free shelter and a mode of transport. what kind of an interaction does this exhibit? . a. parasitism. b. competition. c. predation

Aneuron is stimulated with an electric pulse. the action potential is detected at a point 3.70 cm down the axon 0.0052 s later.when the action potential is detected 7.20 cm from the point of stimulation, the time required is 0.0063 s. what is the speed of the electric pulse along the axon? (why are two measurements needed instead of only one? )

Select the correct answer from each drop-down menu. in an experiment, dr. travis examined the effects of calcium intake on osteoporosis, a condition that causes an increased risk of bone fractures. the amount of calcium is variable. the risk of bone fractures .

Agroup of organisms that changes over time is said to