lipids differ in their degree of saturation or unsaturation due to their number of a. peptide linkages b. amino acids c. double bonds d. saccharide units e. oxygen atoms

c. double bonds is the correct answer.

Explanation:

Saturated fats: no double bond is present in their chemical structure,they have single bond.

In room temperature they are solids.

They are present in different variety of food like

Unsaturated fats: They have one or more double present in their chemical structure.

In room temperature they are liquid.

food having unsaturated fats are

Thus lipids differ in their degree of saturation or unsaturation due to their number of double bonds.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

well for one plants are always the producer, so a is the answer. a wolf is more of the consumer(predator) and the deer is the prey so i know those two are out of the question. also mushrooms are fungi/fungus so a is the producer.