Suppose a scientist discovers fossils of ancient horses in an area. The fossilized horses are much smaller than modern horses. They are found in the same layer as
many fossilized tree trunks. Today, horses still live in the area, but it is now open
grassland
How do you think the environment has changed over time, and how could this
change have led modern horses to be larger than ancient horses?

A60-tooth gear is connected to a 72-tooth gear. if the smaller gear turns 12 times, how many turns does the larger gear make?

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).