Sciences
COMPREHENSIVE SCIENCE REVIEW (2026/2027) - GALEN COLLEGE
(1) A nurse is teaching a couple about autosomal recessive inheritance. If both parents are
carriers of a recessive gene, what is the probability that their child will have the disorder?
A. 25%
B. 50%
C. 75%
D. 100%
CORRECT ANSWER: A
Scientific Rationale: In autosomal recessive inheritance, if both parents are carriers (Aa), there is a 25%
chance of the child being affected (aa), a 50% chance of being a carrier (Aa), and a 25% chance of being
unaffected (AA).
(2) Which chromosomal abnormality is characterized by an extra copy of chromosome 21?
A. Turner Syndrome
B. Klinefelter Syndrome
C. Down Syndrome
D. Edwards Syndrome
CORRECT ANSWER: C
Scientific Rationale: Down Syndrome is also known as Trisomy 21, resulting from three copies of
chromosome 21 instead of two.
,(3) During the menstrual cycle, which hormone surge triggers ovulation?
A. Estrogen
B. Progesterone
C. Luteinizing Hormone (LH)
D. Follicle-Stimulating Hormone (FSH)
CORRECT ANSWER: C
Scientific Rationale: A sharp rise in Luteinizing Hormone (LH), known as the LH surge, triggers the release
of the egg from the follicle (ovulation).
(4) Where does fertilization of the ovum typically occur in the female reproductive system?
A. Uterus
B. Ovary
C. Fallopian tube (Ampulla)
D. Cervix
CORRECT ANSWER: C
Scientific Rationale: Fertilization normally occurs in the ampulla, which is the widest part of the fallopian
tube.
(5) In fetal development, at which week does the heart begin to beat?
A. Week 2
B. Week 4
C. Week 8
D. Week 12
CORRECT ANSWER: B
Scientific Rationale: The fetal heart begins to beat and circulate blood by approximately the end of the
4th week of gestation.
,(6) The 'foramen ovale' in the fetal heart allows blood to flow between which two structures?
A. Right atrium to Left atrium
B. Right ventricle to Left ventricle
C. Pulmonary artery to Aorta
D. Umbilical vein to Vena cava
CORRECT ANSWER: A
Scientific Rationale: The foramen ovale is an opening that allows blood to bypass the lungs by flowing
directly from the right atrium to the left atrium.
(7) Which vitamin is essential for the absorption of calcium from the gastrointestinal tract?
A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin K
CORRECT ANSWER: C
Scientific Rationale: Vitamin D (calcitriol) is required for the active transport and absorption of calcium in
the small intestine.
(8) What is the primary site of nutrient absorption in the human body?
A. Stomach
B. Large Intestine
C. Small Intestine
D. Liver
CORRECT ANSWER: C
Scientific Rationale: The small intestine, particularly the jejunum and ileum, is the primary site for the
absorption of most nutrients due to its large surface area provided by villi.
, (9) Which organelle is known as the 'powerhouse' of the cell because it generates ATP?
A. Nucleus
B. Ribosome
C. Mitochondria
D. Golgi Apparatus
CORRECT ANSWER: C
Scientific Rationale: Mitochondria are responsible for aerobic respiration and the production of ATP
(cellular energy).
(10) In a hypertonic solution, what happens to a red blood cell?
A. It swells and bursts (hemolysis).
B. It remains the same size.
C. It shrinks (crenation).
D. It divides via mitosis.
CORRECT ANSWER: C
Scientific Rationale: In a hypertonic solution, water leaves the cell via osmosis to balance the higher
solute concentration outside, causing the cell to shrink or crenate.
(11) A nurse is teaching a couple about autosomal recessive inheritance. If both parents are
carriers of a recessive gene, what is the probability that their child will have the disorder?
A. 25%
B. 50%
C. 75%
D. 100%
CORRECT ANSWER: A
Scientific Rationale: In autosomal recessive inheritance, if both parents are carriers (Aa), there is a 25%
chance of the child being affected (aa), a 50% chance of being a carrier (Aa), and a 25% chance of being
unaffected (AA).