List the major subdivisions or components for each of the four types of compounds -carbohydrates, lipids, proteins, and nucleic acids-within living organisms. For example, fats are one major subdivision of lipids.

Fossils can only be formed when? if mud, silt or tar is in the area to preserve the fossil ierosion does not occur and allows the fossil to form oxygen and microorganisms cannot decay the bones the area is dry and does not contain mud or silt

Amale bird-of-paradise uses a dance to attract mates in which it flaps its tail feathers on the ground and jumps around a potential female mate. a different male bird-of-paradise does a similar dance but it jumps around the female in the opposite direction. the female bird is only attracted to one style of dance, in one direction.

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.