In Forest Ecosystems, Bears Often Eat a Varied Diet

question 185

Multiple Choice

In forest ecosystems, bears often eat a varied diet.Two food chains in which they may participate are: If bears eat only rodents, they are secondary consumers.If they eat both rodents and berries, they are omnivores.How will ecosystem NPP change if bears act as omnivores rather than secondary consumers?

• A) NPP will not change; the ecosystem needs a certain amount of primary production and will produce it.
• B) NPP will increase; the ecosystem will produce enough berry bushes to feed both bears and rodents.
• C) NPP will increase; bears control the populations of both rodents and berry bushes, resulting in higher NPP.
• D) NPP will decrease; rodents control berry bushes, but bears cannot control rodent populations because rodents are too numerous.
• E) NPP will decrease; bears benefit berry bushes by controlling rodents, but they also eat berries, which decreases NPP.

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Definitions:

Genomic Library

A collection of DNA fragments that represent the entire genome of an organism, stored in vectors and maintained in host cells for study.

Spliced

The process of removing introns and joining exons together in a pre-mRNA molecule to form a mature mRNA strand.

Plasmids

Small, circular, double-stranded DNA molecules, distinct from a cell's chromosomal DNA, that can replicate independently and are found primarily in bacteria.

Cloning Vectors

DNA molecules used to transfer foreign genetic material into a host cell, where it can be replicated and possibly expressed.