BIO 200 PRACTICE TEST | LATEST 2026/2027 | ACTUAL QUESTIONS AND MULTIPLE ANSWERS CHOICES | RATED A+

BIO 200 PRACTICE TEST | LATEST 2026/2027 |
ACTUAL QUESTIONS AND MULTIPLE ANSWERS
CHOICES | RATED A+


1. Describe how histone acetylation influences gene expression.
e. e. e. e. e. e.




e . Histone acetylation causes DNA to become more tightly packed,
e. e. e. e. e. e. e. e.



e. inhibiting transcription. e.




e . Histone acetylation has no effect on gene expression.
e. e. e. e. e. e. e.




e . Histone acetylation leads to a more relaxed chromatin
e. e. e. e. e. e. e.



e. structure, facilitating active gene transcription.
e. e. e. e.




e . Histone acetylation directly alters the DNA sequence, resulting in
e. e. e. e. e. e. e. e.



e. mutations.

2. Describe how Hox genes influence the overall structure of an
e. e. e. e. e. e. e. e. e.



organism during development.
e. e. e.




e . Hox genes initiate the replication of DNA during cell division.
e. e. e. e. e. e. e. e. e.




e . Hox genes encode enzymes that facilitate metabolic processes.
e. e. e. e. e. e. e.




e . Hox genes regulate the production of signaling molecules in cells.
e. e. e. e. e. e. e. e. e.




e. Hox genes determine the anterior-posterior axis and
e. e. e. e. e. e.



segment identity, influencing the overall body structure.
e. e. e. e. e. e. e.




3. How does the lac operon get turned on?
e. e. e. e. e. e. e.




Some lactose is converted to allolactose. Allolactose binds the
e. e. e. e. e. e. e. e. e.



repressor. The repressor changes its own shape so it no
e. e. e. e. e. e. e. e. e. e.



longer binds the operator DNA. This allows transcription.
e. e. e. e. e. e. e. e.

, Lactose binds the DNA, stabilizes the holoenzyme, and initiates
e . e. e. e. e. e. e. e. e.



transcription.
e.




e .Lactose is attached to histone proteins. This modifies the chromatin
e. e. e. e. e. e. e. e. e.



structure and increases gene expression.
e. e. e. e. e.

,4. Which of the following best describes a difference between viruses
e. e. e. e. e. e. e. e. e.



and prions?
e. e.




e . Viruses are infections, but prions are not.
e. e. e. e. e. e.




e. Prions contain membrane-bound organelles, but viruses do
e. e. e. e. e. e.




not.
e. e. e. Prions reproduce sexually, but viruses do not.
e. e. e. e. e. e.




e . Viruses contain nucleic acid, but prions do not.
e. e. e. e. e. e. e.




5. What characteristic of viruses distinguishes them as acellular organisms?
e. e. e. e. e. e. e. e.




e . are unicellular
e.




e . lack metabolic machinery
e. e.




e . can infect cells
e. e.




e . contain no genetic material e. e. e.




6. Describe the basic structure of a virus and its significance in viral function.
e. e. e. e. e. e. e. e. e. e. e. e.




e . A virus has a cell membrane that allows it to interact with host cells.
e. e. e. e. e. e. e. e. e. e. e. e. e.




e. A virus is composed of nucleic acid surrounded by a protein
e. e. e. e. e. e. e. e. e. e.



e. capsid, which protects the genetic material and aids in infection.
e. e. e. e. e. e. e. e. e.




e. A virus is made up of DNA, RNA, and mitochondria to facilitate energy
e. e. e. e. e. e. e. e. e. e. e. e.



e. production.

e . A virus consists of RNA and ribosomes that help in protein synthesis.
e. e. e. e. e. e. e. e. e. e. e.




7. Which of the following is correct regarding the extracellular matrix?
e. e. e. e. e. e. e. e. e.




B) Holds cells together to form a tissue.
e. e. e. e. e. e.




C) Allows cells within a tissue to communicate.
e. e. e. e. e. e.




A) Composed primarily of glycoproteins and collagen.
e. e. e. e. e. e.

, E) B and C only.
e. e. e. e.




D) All of the above. e. e. e.




8. The phenomenon known as "RNAi" (RNA interference) can be
e. e. e. e. e. e. e. e.



used experimentally to
e. e. e.




e . interfere with replication e. e.




e. reduce translation rate from a specific gene promoter
e. e. e. e. e. e. e.




e. e. interfere with the splicing of a specific RNA e. e. e. e. e. e. e.




e . reduce expression of a specific target gene
e. e. e. e. e. e.




9. What is one of the primary uses of RNA interference (RNAi) in
e. e. e. e. e. e. e. e. e. e. e.



biological research?
e. e.




e . Cell division regulation
e. e.




e . Gene knockout studies e. e.




e. Protein synthesis enhancement e. e.




e. e. Viral replication inhibition
e. e.




10. Why do some cells respond to a chemical signal while others do not?
e. e. e. e. e. e. e. e. e. e. e. e.




e. Target cells express the appropriate receptors to that
e. e. e. e. e. e. e.



e. chemical signal e.




e . Target cells do not have the appropriate receptor
e. e. e. e. e. e. e.




e . Only target cells release the appropriate chemical
e. e. e. e. e. e.




signal
e. e. e. None of the answers are correct e. e. e. e. e.




11. What is the primary method by which cells in multicellular
e. e. e. e. e. e. e. e. e.



organisms communicate with each other?
e. e. e. e. e.