10. Unlike energy, matter cycles, This means that
(A) An ecosystem cannot lose chemicals from it.
(B) Ecosystems can acquire chemicals that are used up from other ecosystems.
(C) When models are built for ecosystems, all of the materials should be able to be accounted
(D) Matter is being continually converted into heat and back into matter.
(E) Chemicals contain energy, but energy doesn't contain chemicals.

6. Polygamous relationship is (A) One male mates with one female. (B) One sex mates with several of other sex. (C) One male mates with many females. (D) One female mates with many males. (E) None of above.

7. Population ecologists are primarily interested in (A) Understanding how biotic and abiotic factors influence the density, distribution, size, and age structure of populations. (B) The overall vitality of a population of organisms. (C) How humans affect the size of wild populations of organisms. (D) Studying interactions among populations of organisms that inhabit the same area. (E) How populations evolve as natural selection acts on heritable variations among individuals and changes in gene frequency.

8. Dispersion patterns tend to be highly dependent on the spatial scale of the observer. For example, football players lined up on the scrimmage line are clumped at the scale of 100 yards but uniformly dispersed at the scale of a meter. An example of animals that are likely to be clumped at a large scale but uniformly distributed at a small scale is (A) Buffalo grazing on a prairie. (B) Bluegills swimming in a northern lake. (C) Ant nests in an abandoned field. (D) Red-winged blackbirds in a cattail marsh. (E) All of the above.

9. Disturbance is an important component of succession because it (A) Removes keystone species. (B) Changes the biome from one kind to another. (C) Introduces invasive species. (D) Is associated with humans. (E) Tends to promote earlier successional stages.

11. Gross primary productivity is higher than net primary productivity. The difference between the two is (A) The amount of energy producers burn when they metabolize. (B) Typically the ratio between the biomass of producers and the biomass of consumers. (C) An important measure of ecosystem productivity. (D) Energy that is lost into outer space due to metabolic inefficiencies. (E) EerBy that is stored in plant tissues.

12. Why are big, predatory animals rare? Most big, predatory animals are tertiary consumers, which implies that (A) typically, they are highly territorial. (B) It's hard for an ecosystem to support many of them because so much energy is lost at each level of energy exchange. (C)By overexploitation, humans have caused many predatory species to become endangered. (D) It takes a long time for big, predatory animals to evolve. (E) It's hard for a big animal to move through dense vegetation

13. A localized group of organisms that belong to the same species is called a_______. (A) community (B) family (C) ecosystem (D) population (E) Biosphere

14. How many electrons are involved in a triple covalent bond? (A) 3 (B) 6 (C) 9 (D) 12 (E)15

15. What is the hydroxyl ion (OH-) concentration of a solution of pH 8? (A) 8M (B) 8 x 10-6 M (C)10-6 M (D) 10-8 M (E) 8 x 10-8 M

16. Use the following figure to answer the question. The figure shows the structures of glucose and fructose. These two molecules are________.(A) isotopes (B) cis-trans isomers (C) enantiomers (D) epimers (E) structural isomers