USABO OPEN EXAM NEWEST 2025 ACTUAL

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USABO OPEN EXAM NEWEST 2025 ACTUAL

EXAM COMPLETE 150 QUESTIONS AND

CORRECT DETAILED ANSWERS (VERIFIED

ANSWERS) |ALREADY GRADED A+

Which of the following would be most likely to increase competition among the members of the vole population in a given area?

• An increase in the number of hawk predators
• An increase in the reproduction rate of voles
• An increase in temperature
• An increase in the food supply
• An epidemic of rabies within the vole population -

ANSWER-B. An increase in the reproduction rate of voles

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Rationale;Resource limitation in crowded populations can stop population growth. Population density intensifies intraspecific competition for declining nutrients, resulting in a lower birth rate.

Tobacco mosaic virus has RNA rather than DNA as its genetic material. If the RNA genome from a tobacco mosaic virus is mixed with proteins from a human rhinovirus, the result is a mixed virus. If that virus could infect a cell and reproduce, what would you expect the resulting viruses to be like?

• A hybrid including genetic material from tobacco

mosaic virus and proteins from the rhinovirus

• A hybrid including proteins from tobacco mosaic virus

and genetic material from the rhinovirus

• Rhinovirus
• Tobacco mosaic virus
• No viruses would result because no viral DNA was

present - ANSWER-D. Tobacco mosaic virus

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Rationale;Virus genomes may consist of double- stranded DNA, single-stranded DNA, double-stranded RNA, or single-stranded RNA depending on the specific type of virus. Tobacco mosaic virus has a rigid, rodshaped capsid. The genetic material from the tobacco mosaic virus serves as the template for the human rhinovirus to replicate itself and produce new capsid proteins by transcription and translation. The new viral DNA and capsid proteins assemble into tobacco mosaic virus particles, which then leave the cell.

An amphipathic molecule is a molecule that is

characterized by:

• 2 different forms that are mirror images of each other.
• an amino group.
• a hydrophilic end and a hydrophobic end.
• a positively charged end and a negatively charged end.
• rarely being found in cell membranes. - ANSWER-C. a

hydrophilic end and a hydrophobic end. 3 / 4

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Rationale;An amphipathic molecule is a phospholipid that has both a hydrophilic region and a hydrophobic region.

The function of a molecular chaperone is to:

• act as an energy source during the polymerization of

amino acids into a polypeptide.

• act as a carrier molecule and bring "activated"

monomers to a polymer for incorporation.

• bind to specific structures on the polypeptide in order

to assist the folding of a protein into its correct three dimensional shape.

• unfold proteins with the incorrect three-dimensional

shape and refold them into the proper shape.

• transport rRNA from the nucleus to the cytoplasm. -

ANSWER-C. bind to specific structures on the polypeptide in order to assist the folding of a protein into its correct three dimensional shape.

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