Small birds will often mob large predatory birds such as owls and hawks. this behavior involves the smaller birds gathering or flying near the larger bird, calling loudly, and even striking the larger bird, and may result in the larger bird leaving the area. this behavior is risky for the smaller birds but is commonly seen. from this description we can reasonably conclude that:
a. birds are not intelligent enough to know that the larger bird is dangerous
b. this behavior is clearly maladaptive and should be eliminated by natural selection
c. there must be some advantage of this behavior, such as protecting their chicks, that makes the risks worthwhile
d. these birds must have learned this behavior by operant conditioning

Which statements about the fluid mosaic structure of a membrane are correct? select the three correct statements.which statements about the fluid mosaic structure of a membrane are correct? select the three correct statements.the framework of a membrane is a bilayer of phospholipids with their hydrophilic heads facing the aqueous environment inside and outside of the cell and their hydrophobic tails clustered in the center.because membranes are fluid, membrane proteins and phospholipids can drift about in the membrane.the diverse proteins found in and attached to membranes perform many important functions.the kinky tails of some proteins keep the membrane fluid by preventing the component molecules from packing solidly together.membranes include a mosaic, or mix, of carbohydrates embedded in a phospholipid bilayer.

Chloroplasts and bacteria are in size. a. similar b. at different ends of the size range c. exactly the same d. none of these

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).