ESTUDYR
BIOL 100 UPDATED EXAM WITH MOST TESTED QUESTIONS
AND ANSWERS | GRADED A+ | ASSURED SUCCESS WITH
DETAILED RATIONALES
In prokaryotic cells, where is the chromosome typically located?
A. Nucleus
B. Nucleoid region (central area containing coiled DNA)
C. Mitochondrion
D. Golgi apparatus
Rationale: Prokaryotes lack a membrane-bound nucleus; their DNA is localized in the nucleoid.
Which cellular structure is the primary site of protein synthesis?
A. Mitochondria
B. Nucleus
C. Ribosomes
D. Lysosomes
Rationale: Ribosomes translate mRNA into polypeptides (proteins).
Which structure forms the semipermeable barrier that encloses a cell’s cytoplasm?
A. Cell wall
B. Plasma (cell) membrane
C. Ribosome
D. Endoplasmic reticulum
Rationale: The plasma membrane (phospholipid bilayer) controls exchange with the
environment.
Which feature provides rigid structural support in many bacteria and plant cells?
A. Plasma membrane
B. Capsule
C. Cell wall
D. Flagella
Rationale: The cell wall (peptidoglycan in bacteria; cellulose in plants) gives rigidity and shape.
What is the primary function of a bacterial capsule?
A. Protein synthesis
B. Energy production
C. Adhesion and protection (sticky outer coat)
D. Intracellular digestion
Rationale: Capsules help bacteria adhere to surfaces and protect against immune defenses.
, ESTUDYR
Which bacterial appendage mediates attachment and DNA exchange during conjugation?
A. Flagellum
B. Capsule
C. Pili (fimbriae)
D. Ribosome
Rationale: Pili facilitate adhesion and conjugative transfer of plasmids between bacteria.
Which structure enables many bacteria to move through liquid environments?
A. Cilia
B. Pili
C. Flagella
D. Microvilli
Rationale: Flagella are long, whip-like appendages that propel bacterial cells.
A mutation that occurs accidentally during DNA replication is called:
A. Induced mutation
B. Spontaneous mutation
C. Frameshift only
D. Germline insertion
Rationale: Spontaneous mutations arise from errors in replication without an external cause.
Which of the following is an environmental factor that can cause mutations?
A. DNA polymerase proofreading
B. Cellular repair enzymes
C. UV radiation or chemical exposure
D. mRNA translation
Rationale: External agents like UV light and mutagenic chemicals alter DNA and cause
mutations.
Mutations caused by exposure to ionizing radiation are called:
A. Chemical-induced mutations
B. Spontaneous mutations
C. Radiation-induced mutations
D. Transcription errors
Rationale: Radiation (UV, X-rays) directly damages DNA leading to radiation-induced mutations.
Which type of mutation results from exposure to mutagenic chemicals?
A. Radiation-induced mutation
B. Chemical-induced mutation
C. Spontaneous mutation only
BIOL 100 UPDATED EXAM WITH MOST TESTED QUESTIONS
AND ANSWERS | GRADED A+ | ASSURED SUCCESS WITH
DETAILED RATIONALES
In prokaryotic cells, where is the chromosome typically located?
A. Nucleus
B. Nucleoid region (central area containing coiled DNA)
C. Mitochondrion
D. Golgi apparatus
Rationale: Prokaryotes lack a membrane-bound nucleus; their DNA is localized in the nucleoid.
Which cellular structure is the primary site of protein synthesis?
A. Mitochondria
B. Nucleus
C. Ribosomes
D. Lysosomes
Rationale: Ribosomes translate mRNA into polypeptides (proteins).
Which structure forms the semipermeable barrier that encloses a cell’s cytoplasm?
A. Cell wall
B. Plasma (cell) membrane
C. Ribosome
D. Endoplasmic reticulum
Rationale: The plasma membrane (phospholipid bilayer) controls exchange with the
environment.
Which feature provides rigid structural support in many bacteria and plant cells?
A. Plasma membrane
B. Capsule
C. Cell wall
D. Flagella
Rationale: The cell wall (peptidoglycan in bacteria; cellulose in plants) gives rigidity and shape.
What is the primary function of a bacterial capsule?
A. Protein synthesis
B. Energy production
C. Adhesion and protection (sticky outer coat)
D. Intracellular digestion
Rationale: Capsules help bacteria adhere to surfaces and protect against immune defenses.
, ESTUDYR
Which bacterial appendage mediates attachment and DNA exchange during conjugation?
A. Flagellum
B. Capsule
C. Pili (fimbriae)
D. Ribosome
Rationale: Pili facilitate adhesion and conjugative transfer of plasmids between bacteria.
Which structure enables many bacteria to move through liquid environments?
A. Cilia
B. Pili
C. Flagella
D. Microvilli
Rationale: Flagella are long, whip-like appendages that propel bacterial cells.
A mutation that occurs accidentally during DNA replication is called:
A. Induced mutation
B. Spontaneous mutation
C. Frameshift only
D. Germline insertion
Rationale: Spontaneous mutations arise from errors in replication without an external cause.
Which of the following is an environmental factor that can cause mutations?
A. DNA polymerase proofreading
B. Cellular repair enzymes
C. UV radiation or chemical exposure
D. mRNA translation
Rationale: External agents like UV light and mutagenic chemicals alter DNA and cause
mutations.
Mutations caused by exposure to ionizing radiation are called:
A. Chemical-induced mutations
B. Spontaneous mutations
C. Radiation-induced mutations
D. Transcription errors
Rationale: Radiation (UV, X-rays) directly damages DNA leading to radiation-induced mutations.
Which type of mutation results from exposure to mutagenic chemicals?
A. Radiation-induced mutation
B. Chemical-induced mutation
C. Spontaneous mutation only
