Producers are the most important biotic factor in an ecosystem.

a. True

b. False

What are two reasons why cells divide rather than continue to grow indefinitely?

What process results in genetically different bacteria? a. binary fission b. respiration c. conjugation d. asexual reproduction

Describe the role of energy in chemical reactions?

Coliforms A. are an informal grouping of enterics. B. ferment lactose. C. includes E. coli. D. are used as indicators of fecal contamination. E. All of the choices are correct.

True or false Classical conditioning occurs when the unconditioned stimulus evokes a response from a neutral stimulus.

Forest elephants in Africa have been confirmed as a different species from the larger savanna elephant seen here. Scientists believe the savanna elephant is as different from the forest elephant as Asian elephants are from woolly mammoths.

What competitive processes or forces are ever-present during a star's lifetime?

Which occurs during transcription? A. DNA is copied to create a second DNA strand. B. mRNA codons and tRNA anticodons assemble amino acids. C. DNA is unzipped with the aid of DNA polymerase. D. mRNA is synthesized from a strand of DNA.

In a beach ecosystem, what can limit growth of organisms? A. ocean and rocks B. oxygen C. abundant food source D. moderate temperatures

What process do the arrows for oxygen going in and water coming out represent in the Figure 9-2 diagram of the mitochondria?