How do organisms get the energy they need?
a. by burning food molecules and releasing their energy as heat
b. by breathing oxygen into the lungs and combining it with carbon dioxide
c. by breaking down food molecules gradually and capturing their chemical energy
d. by using the sun s energy to break down food molecules and form chemicals

If someone could do the first couple, just so i can see how it's done that would be great! 20 points. complete a dichotomous key for the 10 leaves on the common leaves sheet. the chart provided here allows for 11 pairs of statements. depending on how you build your dichotomous key, you may or may not need all of them, or you may need to add some.

Select the correct answer from each drop-down menu proteins are

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?