MCAT BIOLOGY PRACTICE QUESTIONS –
UWORLD
Between enveloped viruses and non-enveloped viruses, what is more resistant to heat, detergents, and
changes in moisture? - answer ✔✔-non-eveloped virsuses
Sense vs antisense? Positive sense RNA vs Negative sense RNA? - answer ✔✔-coding vs template strand;
virus genetic material than can directly be used for translation vs virus genetic material that has to be
transcribed into positive sense RNA
What viruses utilize the host machinery most often? - answer ✔✔-double stranded DNA viruses
Can a light microscope be used to see viruses? How many times is a virus smaller than eukaryotic cells?
what about prokaryotic bacteria? - answer ✔✔-1000 times, 100 times
Why are retroviruses unique? - answer ✔✔-carry two identical +ssRNA strands and are enveloped
What is a bacteriophage? - answer ✔✔-infects a bacterial cell without fully entering the cytoplasm
How does a prion cause the misfolding of other proteins? Is a prion a virus? - answer ✔✔-by changing
their secondary structure; no, it is a subviral particle
What is a viroid? - answer ✔✔-a circular, single stranded RNA that infects plants, binds to RNA
sequences and silences them
,What does PTH do in the kidneys? - answer ✔✔-Promotes the synthesis of calcitriol or the active form of
Vitamin D, this then leads to the small intestine absorbing dietary calcium
The PI 2nd messenger cascade - answer ✔✔-1. GTP bound alpha subunit activates phospholipase C
2. Membrane bound phospholipase C cleaves PIP into IP3 and DAG
3. IP3 binds to receptors on ER and mitochondria to release calcium
4. DAG and Calcium activates Protein Kinase C
Where is calcitonin released from? Where is the site of T lymphocyte maturation? - answer ✔✔-thyroid
gland; thymus
What is the exocrine function of the pancreas? - answer ✔✔-the secretion of pancreatic juices and
bicarbonate to aid in digestion
What are two examples of eukaryotic cells? Prokaryotic cells? What do eukaryotic cells and prokaryotic
cells both have? - answer ✔✔-Fungi and Protozoa; Bacteria and Archaea; phospholipid bilayer called the
cell membrane
Enveloped viruses have what kind of membrane? - answer ✔✔-phospholipid bilayer
Parallel evolution - answer ✔✔-two species that share a common ancestor go through similar
evolutionary changes due to similar selective pressures
Convergent evolution example - answer ✔✔-shark and dolphin
Divergent evolution; example - answer ✔✔-when two or more species sharing a common ancestor
become more different over time; Dog, wolf, and fox
What 3 aspects of sperm are important for fertilization of an oocyte? - answer ✔✔-acrosomal enzymes,
mitochondria, microtubules
, Developmental pathway of sperm? - answer ✔✔-spermatogonium, spermatocyte, spermatid,
spermatozoon
When does the primary oocyte remain stalled in prophase I? - answer ✔✔-from infancy to puberty
Till what point does the secondary oocyte remain stalled in metaphase II? - answer ✔✔-Till fertilization
by sperm
When blood pressure or blood volume is low, how does Angiotensin II counter this? - answer ✔✔-
releases aldosterone from adrenal cortex to promote the reabsorption of Na+ and water and increase
BP, also causes the constriction of blood vessels
Where does aldosterone and ADH act? Between the two what only affects osmolarity? Where is ADH
released from? - answer ✔✔-acts at the distal convoluted tube and collecting duct; aldosterone; the
posterior pituitary gland
When urine collects in the bladder, what muscles are contracted to prevent urine flow? - answer ✔✔-
IUS and EUS
During urination, what muscles are under involuntary control? - answer ✔✔-detrusor muscles around
the bladder and the IUS
What is osmotic pressure? - answer ✔✔-Pressure that causes water to move an area of low solute
concentration to high solute concentration
Where does filtration in the kidneys occur? - answer ✔✔-Between the glomerular capillaries and
Bowman's capsule
Charged particles like Na+ need what for diffusion and have what kind of gradient? - answer ✔✔-
membrane proteins for facilitated diffusion, electrochemical gradient
UWORLD
Between enveloped viruses and non-enveloped viruses, what is more resistant to heat, detergents, and
changes in moisture? - answer ✔✔-non-eveloped virsuses
Sense vs antisense? Positive sense RNA vs Negative sense RNA? - answer ✔✔-coding vs template strand;
virus genetic material than can directly be used for translation vs virus genetic material that has to be
transcribed into positive sense RNA
What viruses utilize the host machinery most often? - answer ✔✔-double stranded DNA viruses
Can a light microscope be used to see viruses? How many times is a virus smaller than eukaryotic cells?
what about prokaryotic bacteria? - answer ✔✔-1000 times, 100 times
Why are retroviruses unique? - answer ✔✔-carry two identical +ssRNA strands and are enveloped
What is a bacteriophage? - answer ✔✔-infects a bacterial cell without fully entering the cytoplasm
How does a prion cause the misfolding of other proteins? Is a prion a virus? - answer ✔✔-by changing
their secondary structure; no, it is a subviral particle
What is a viroid? - answer ✔✔-a circular, single stranded RNA that infects plants, binds to RNA
sequences and silences them
,What does PTH do in the kidneys? - answer ✔✔-Promotes the synthesis of calcitriol or the active form of
Vitamin D, this then leads to the small intestine absorbing dietary calcium
The PI 2nd messenger cascade - answer ✔✔-1. GTP bound alpha subunit activates phospholipase C
2. Membrane bound phospholipase C cleaves PIP into IP3 and DAG
3. IP3 binds to receptors on ER and mitochondria to release calcium
4. DAG and Calcium activates Protein Kinase C
Where is calcitonin released from? Where is the site of T lymphocyte maturation? - answer ✔✔-thyroid
gland; thymus
What is the exocrine function of the pancreas? - answer ✔✔-the secretion of pancreatic juices and
bicarbonate to aid in digestion
What are two examples of eukaryotic cells? Prokaryotic cells? What do eukaryotic cells and prokaryotic
cells both have? - answer ✔✔-Fungi and Protozoa; Bacteria and Archaea; phospholipid bilayer called the
cell membrane
Enveloped viruses have what kind of membrane? - answer ✔✔-phospholipid bilayer
Parallel evolution - answer ✔✔-two species that share a common ancestor go through similar
evolutionary changes due to similar selective pressures
Convergent evolution example - answer ✔✔-shark and dolphin
Divergent evolution; example - answer ✔✔-when two or more species sharing a common ancestor
become more different over time; Dog, wolf, and fox
What 3 aspects of sperm are important for fertilization of an oocyte? - answer ✔✔-acrosomal enzymes,
mitochondria, microtubules
, Developmental pathway of sperm? - answer ✔✔-spermatogonium, spermatocyte, spermatid,
spermatozoon
When does the primary oocyte remain stalled in prophase I? - answer ✔✔-from infancy to puberty
Till what point does the secondary oocyte remain stalled in metaphase II? - answer ✔✔-Till fertilization
by sperm
When blood pressure or blood volume is low, how does Angiotensin II counter this? - answer ✔✔-
releases aldosterone from adrenal cortex to promote the reabsorption of Na+ and water and increase
BP, also causes the constriction of blood vessels
Where does aldosterone and ADH act? Between the two what only affects osmolarity? Where is ADH
released from? - answer ✔✔-acts at the distal convoluted tube and collecting duct; aldosterone; the
posterior pituitary gland
When urine collects in the bladder, what muscles are contracted to prevent urine flow? - answer ✔✔-
IUS and EUS
During urination, what muscles are under involuntary control? - answer ✔✔-detrusor muscles around
the bladder and the IUS
What is osmotic pressure? - answer ✔✔-Pressure that causes water to move an area of low solute
concentration to high solute concentration
Where does filtration in the kidneys occur? - answer ✔✔-Between the glomerular capillaries and
Bowman's capsule
Charged particles like Na+ need what for diffusion and have what kind of gradient? - answer ✔✔-
membrane proteins for facilitated diffusion, electrochemical gradient
