Portage Learning
LANIF · 012 DOIB
✚
G
★
A Division of Geneva College
EST. 1848
P R O C H R I S T O E T P AT R I A
BIOD 210 — Final Examination
G E N E T I CS · M O L E CU L A R B I O LO G Y · C A N C E R B I O LO G Y · M E N D E L I A N I N H E R I TA N C E
INSTITUTION Portage Learning / Geneva College COURSE CODE BIOD 210
PROGRAM Bachelor of Science — Pre-Health / ACADEMIC YEAR
Biology
EXAM TITLE Final Examination — Genetics TOTAL QUESTIONS 40 Questions
COURSE TITLE Genetics FORMAT Multiple Choice — Select the
Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question.
▸ Content spans Mendelian genetics, molecular biology, cancer biology, cytogenetics, and epigenetics.
▸ Correct answers and detailed rationales appear below each question for review purposes.
▸ All genetic terminology and concepts reflect current standard references.
, SECTION I — HISTORY, FOUNDATIONAL CONCEPTS &
Questions 1 – 12
CYTOGENETICS
1. How do the ideas of epigenesis and preformation directly contradict each other?
A. Epigenesis stated that all organisms are preformed in the gametes; preformation stated
that development occurs gradually through environmental influence.
B. Preformation postulated that a fertilized egg contained a miniaturized version of a tiny
human (homunculus); epigenesis stated that a fertilized egg undergoes a series of
developmental events that eventually form a human.
C. Both theories agreed on developmental mechanism but differed on the timing of organ
formation.
D. Preformation stated that development is entirely environmental; epigenesis stated that
development is entirely genetic.
CORRECT ANSWER B — Preformation postulated that a fertilized egg contained a miniaturized
version of a tiny human (homunculus); epigenesis stated that a fertilized
egg undergoes a series of developmental events that eventually form a
human.
RATIONALE Preformation theory held that the fertilized egg contained a fully formed
miniature human (homunculus) that simply grew in size. Epigenesis directly
contradicted this by proposing that development proceeds through a series of
progressive changes — structures emerge gradually from an initially
undifferentiated egg through sequential developmental events. This was a
fundamental conceptual shift in embryology and developmental biology, moving
from the idea of pre-existing form to emergent complexity.
, 2. Which of the following statements about sex chromosomes is correct?
A. The X and Y chromosomes are equal in size and gene content.
B. Incorrect segregation of X and Y chromosomes is always embryonic lethal.
C. The X chromosome is much larger than the Y chromosome.
D. The X and Y chromosomes share no homology whatsoever.
CORRECT ANSWER C — The X chromosome is much larger than the Y chromosome.
RATIONALE The X chromosome is approximately 155 million base pairs and contains over
1,000 genes, while the Y chromosome is about 59 million base pairs with fewer
than 100 functional genes. The X and Y chromosomes do share regions of
homology (pseudoautosomal regions) that allow for pairing during meiosis.
Incorrect segregation does not always cause embryonic lethality — conditions
such as Turner syndrome (XO) and Klinefelter syndrome (XXY) are viable. The Y
chromosome carries the SRY gene which is the primary determinant of male sex
development.
3. The DNA in a bacteriophage is packaged in the ________, which is shaped like a capsule.
The ________ of the phage pushes the DNA through the host cell membrane much like a
syringe.
A. nucleus / tail fiber
B. head / sheath
C. capsid / envelope
D. body / flagellum
CORRECT ANSWER B — head / sheath
RATIONALE Bacteriophage structure: The DNA is packaged within the phage head (capsid),
which is shaped like a capsule. The tail sheath contracts to push the DNA through
the host cell membrane — analogous to a syringe mechanism. The tail fibers
attach to specific receptor sites on the bacterial surface. This elegant injection
mechanism was famously demonstrated in the Hershey-Chase experiment, which
confirmed that DNA (not protein) is the genetic material. The phage head protects
the viral genome; the sheath provides the mechanical force for injection.
LANIF · 012 DOIB
✚
G
★
A Division of Geneva College
EST. 1848
P R O C H R I S T O E T P AT R I A
BIOD 210 — Final Examination
G E N E T I CS · M O L E CU L A R B I O LO G Y · C A N C E R B I O LO G Y · M E N D E L I A N I N H E R I TA N C E
INSTITUTION Portage Learning / Geneva College COURSE CODE BIOD 210
PROGRAM Bachelor of Science — Pre-Health / ACADEMIC YEAR
Biology
EXAM TITLE Final Examination — Genetics TOTAL QUESTIONS 40 Questions
COURSE TITLE Genetics FORMAT Multiple Choice — Select the
Single Best Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question.
▸ Content spans Mendelian genetics, molecular biology, cancer biology, cytogenetics, and epigenetics.
▸ Correct answers and detailed rationales appear below each question for review purposes.
▸ All genetic terminology and concepts reflect current standard references.
, SECTION I — HISTORY, FOUNDATIONAL CONCEPTS &
Questions 1 – 12
CYTOGENETICS
1. How do the ideas of epigenesis and preformation directly contradict each other?
A. Epigenesis stated that all organisms are preformed in the gametes; preformation stated
that development occurs gradually through environmental influence.
B. Preformation postulated that a fertilized egg contained a miniaturized version of a tiny
human (homunculus); epigenesis stated that a fertilized egg undergoes a series of
developmental events that eventually form a human.
C. Both theories agreed on developmental mechanism but differed on the timing of organ
formation.
D. Preformation stated that development is entirely environmental; epigenesis stated that
development is entirely genetic.
CORRECT ANSWER B — Preformation postulated that a fertilized egg contained a miniaturized
version of a tiny human (homunculus); epigenesis stated that a fertilized
egg undergoes a series of developmental events that eventually form a
human.
RATIONALE Preformation theory held that the fertilized egg contained a fully formed
miniature human (homunculus) that simply grew in size. Epigenesis directly
contradicted this by proposing that development proceeds through a series of
progressive changes — structures emerge gradually from an initially
undifferentiated egg through sequential developmental events. This was a
fundamental conceptual shift in embryology and developmental biology, moving
from the idea of pre-existing form to emergent complexity.
, 2. Which of the following statements about sex chromosomes is correct?
A. The X and Y chromosomes are equal in size and gene content.
B. Incorrect segregation of X and Y chromosomes is always embryonic lethal.
C. The X chromosome is much larger than the Y chromosome.
D. The X and Y chromosomes share no homology whatsoever.
CORRECT ANSWER C — The X chromosome is much larger than the Y chromosome.
RATIONALE The X chromosome is approximately 155 million base pairs and contains over
1,000 genes, while the Y chromosome is about 59 million base pairs with fewer
than 100 functional genes. The X and Y chromosomes do share regions of
homology (pseudoautosomal regions) that allow for pairing during meiosis.
Incorrect segregation does not always cause embryonic lethality — conditions
such as Turner syndrome (XO) and Klinefelter syndrome (XXY) are viable. The Y
chromosome carries the SRY gene which is the primary determinant of male sex
development.
3. The DNA in a bacteriophage is packaged in the ________, which is shaped like a capsule.
The ________ of the phage pushes the DNA through the host cell membrane much like a
syringe.
A. nucleus / tail fiber
B. head / sheath
C. capsid / envelope
D. body / flagellum
CORRECT ANSWER B — head / sheath
RATIONALE Bacteriophage structure: The DNA is packaged within the phage head (capsid),
which is shaped like a capsule. The tail sheath contracts to push the DNA through
the host cell membrane — analogous to a syringe mechanism. The tail fibers
attach to specific receptor sites on the bacterial surface. This elegant injection
mechanism was famously demonstrated in the Hershey-Chase experiment, which
confirmed that DNA (not protein) is the genetic material. The phage head protects
the viral genome; the sheath provides the mechanical force for injection.
