What happens when atp binds to myosin heads during muscle contraction?
a. calcium ions are released from the sarcoplasmic reticulum.
b. calcium ions are taken up by the sarcoplasmic reticulum.
c. cross-bridges between myosin heads and actin filaments are broken.
d. myosin heads form cross-bridges with actin filaments.

Dna. we have heard that we are a product of our dna. but where is it? how do we "get" our dna? it is passed to us, from our parents, but in what form? several vocabulary words associated with inheritance are used interchangeably and sometimes, incorrectly. let's see if you can clear this up for someone just learning about inheritance and cell structure.

What function does a limb serve in each animal how are the limb bones of the four animal similar based on the similarities what can be inferred about the evolution of the poor animals

Which member of the following food chain will be least affected by ddt, a pesticide water pollutant, if bio-magnification is occurring? algae> zooplankton> crayfish> leopard frog> large mouth bass