The spikes on pollen grains probably (a) allow the pollen grain to stick to insects.

(b) allow the pollen grain to fly through the air.

(c) protect the pollen grain from being eaten.

(d) allow insects to stick to the pollen grain.

In the context of the neural impulse, which of the following is true about the depolarization of neuron membranes?

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

When is your respiration rate likely to change? a. when your intestines are digesting b. when your cells have too much glucose c. when your cells need more oxygen d. when your liver is working after a meal