PS: PLEASE DO NOT PUT A LINK IN THE ANSWER SECTION! THERE ARE 4 QUESTION. 1. which term describes primary producers?
a. herbivores
b. abiotic
c. decomposers
d. autotrophs

2. why is a food chain is the simplest model of energy flow between trophic levels in an ecosystem?
a. because it represents only one pathway of energy flow
b. because it only considers producers and primary consumers
c. because it is more complex then a food web

3. which of the following are visual models to represent the flow of energy between trophic levels in an ecosystem? (choose all that apply)
a. energy pyramid
b. food pyramid
c. food web
d. food chain

4. why are primary producers also referred to as autotrophs?
a. they are able to transfer energy throughout an ecosystem
b. they are able to change chemical energy into light energy
c. they are able to transform energy from an unusable form to a usable form
d. they are able to release energy from other organisms on an ecosystem

Is a measure of the resistance to flow. a high liquid has a high resistance to flow and flows slowly. the ancients thought everything in the world was made of 4 we now know that there are 94 naturally occurring and scientists have created another 24 i am certain they will create even more. honey flows slowly because it has a high to flowing. a can be separated by physical means because it contains more than one pure substance and 2 pure substances are not chemically bonded to each other. a cannot be separated by physical means. all matter is made up of all elements are with the same number of protons. if it is just a single or many bonded together, if all of them have the same number of protons, it is an element. in a piece of pure iron metal, all the are joined together, that piece of iron metal is called elemental iron. a single of iron is called elemental iron. a mixture has differences from place to place. we might need a microscope to see them or they might be obvious to the unaided eye. there are surfaces separating it into different phases. a mixture is the same everywhere. it is uniform. there are no surfaces separating it into different phases. if different kinds of atoms (different elements) are bonded together by their electrons, it is called a there are physical means of to isolate the different pure substances in a mixture and there are chemical means of to isolate the different elements in a compound. 1. element 2. compound 3. mixture 4. heterogeneous 5. homogeneous 6. pure substance 7. atoms 8. separation 9. viscosity 10. resistance