Explain why humans can be at different trophic levels on different food chains, but they can never occupy the lowest trophic level.

What is the difference between sex and gender? 1. Sex refers to the biological characteristics/chromosomes a person is born with 2. Sex is what a person identifies as, regardless of biological characteristics 3. Sex is a fluid concept 4.

What was the conclusion that Avery and other scientists discovered?

A particular co-transporter uses the concentration gradient of na + to move an amino acid into the cell. what immediate effect would raising the extracellular na + have? it would ... a. increase the amino acid's rate of entry into the cell. b.

Polonium is a radioactive metal that is used as a heat source in space satellites. polonium has a simple cubic unit cell. how many atoms of po are present in each unit cell?

Tom's company has been contracted to excavate uranium ore with minimal ground disruption. What process should his company use? A. open surface mining B. in situ leaching C. hydraulic fracturing D. deep well excavation

Explain how life is an emergent property of cells

Which heart valves are open during ventricular diastole?

A. what are two reasons that the prevalence rate of a disease in a community could decrease?

Which is used to make many copies of DNA? A. PCR B. Reverse transcriptase C. Gel electrophoresis D. Nuclear tranfer

Light___. requires a medium to travel is refracted when it bounces off a shiny surface is created by vibrations in electric and magnetic fields moves in longitudinal waves