Why do myosin filaments have club-shaped heads?
the heads are where acetylcholine binds to initiate contraction.
the heads bind calcium to initiate contraction.
the heads pull on the z discs during contraction.
the heads attach to and pull actin filaments during contraction.

Plz fast biotechnology is a growing field of applied biology. many crops such as corn have been engineered to be resistant to herbicides. therefore farmers can spray these chemicals to kill weeds growing near the crop without worries of killing the crop itself how does this type of biotechnology work? a. by changing the genetic make up of the crops. b. by causing the crops to kill the weeds. c. by changing the type of crops used. d. by changing the location of the crops.

1. -define adaptation2 explain darwin's theories of descent with modification and natural selection in detail3. -explain how each of these provides evidence for evolution: a. -fossil record, including superposition and transitional fossilsb-anatomy, including homologous structuresc-biological molecules, including dna and proteins4. -explain the difference between convergent and divergent evolution.5. -define and give three examples of artificial selection6. -define and give one example of coevolution.7. -explain biodiversity and how it benefits humans.8. -explain a type of population lest affected by environmental change.

Where is pericardial fulid located