MCAT Biology Practice Questions and
answers
Glucose typically enters the cell through which mechanism?
A. Simple diffusion through the cell membrane
B. Facilitated diffusion through a carrier protein
C. Pinocytosis through a channel protein
D. Active transport by a glucose transport protein - Facilitated diffusion through a
carrier protein
Glucose is too large and polar to move quickly through the cell membrane by
simple diffusion.
Typically the concentration of glucose outside the cell is higher than inside the
cell.
Since glucose is moving down a concentration gradient by entering the cell, the
process does not require ATP.
Glucose typically enters cells by facilitated diffusion through a carrier protein.
,MCAT Biology Practice Questions and
answers
Which type of membrane protein is most likely to be a hormone?
A. Lipid-bound protein
B. Peripheral protein
C. Integral protein
D. Steroid - Peripheral protein
Hormones move through the circulatory system, acting as signaling molecules to
specific organs/cells.
A steroid is not a membrane protein.
An integral protein can not easily leave the cell membrane and would therefore be
a poor signaling molecule.
Lipid-bound proteins remain within the phospholipid bilayer by the fatty acid tails
of phospholipids. They would also be poor signaling molecules.
,MCAT Biology Practice Questions and
answers
Peptide hormones like insulin and growth hormone interact with integral protein
receptors in cell membranes. These hormones can be considered peripheral
membrane proteins.
Pulmonary edema occurs when fluid builds up in the interstitium between the
pulmonary capillaries and the alveoli, and eventually enters the alveoli. How do
you decrease the risk of pulmonary edema?
A. Decrease hydrostatic pressure and increase osmotic pressure
B. Decrease hydrostatic pressure and decrease osmotic pressure
C. Increase hydrostatic pressure and decrease osmotic pressure
D. Increase hydrostatic pressure and increase osmotic pressure - Decrease
hydrostatic pressure and increase osmotic pressure
Hydrostatic pressure is the pressure a liquid exerts on its container, and reflects
the volume of liquid in a space.
Osmotic pressure is the pressure required to prevent movement across a
semipermeable membrane, and reflects the protein content of the blood.
, MCAT Biology Practice Questions and
answers
To decrease the risk of pulmonary edema, hydrostatic pressure exerted by the
fluid must decrease, and osmotic pressure exerted on the fluid must increase.
At what point does crossing over between sister chromatids occur?
A. During anaphase I of meiosis
B. During prophase I of meiosis
C. During anaphase II of meiosis
D. During prophase II of meiosis - During prophase I of meiosis
Crossing over is a form of genetic recombination in which homologous
chromosomes pair up and exchange pieces of their genetic material. Crossing over
occurs in prophase I of meiosis, and is often referred to as synapsis. However,
crossing over occurs between homologous chromosomes, and not between the
sister chromatids of an individual chromosome. Sister chromatids are identical
pieces of DNA joined at the centromere to make up one chromosome.
Your trachea have short hair-like cell process that move the mucus. What is the
name of these hair like structures and which cytoskeletal elements form them?
answers
Glucose typically enters the cell through which mechanism?
A. Simple diffusion through the cell membrane
B. Facilitated diffusion through a carrier protein
C. Pinocytosis through a channel protein
D. Active transport by a glucose transport protein - Facilitated diffusion through a
carrier protein
Glucose is too large and polar to move quickly through the cell membrane by
simple diffusion.
Typically the concentration of glucose outside the cell is higher than inside the
cell.
Since glucose is moving down a concentration gradient by entering the cell, the
process does not require ATP.
Glucose typically enters cells by facilitated diffusion through a carrier protein.
,MCAT Biology Practice Questions and
answers
Which type of membrane protein is most likely to be a hormone?
A. Lipid-bound protein
B. Peripheral protein
C. Integral protein
D. Steroid - Peripheral protein
Hormones move through the circulatory system, acting as signaling molecules to
specific organs/cells.
A steroid is not a membrane protein.
An integral protein can not easily leave the cell membrane and would therefore be
a poor signaling molecule.
Lipid-bound proteins remain within the phospholipid bilayer by the fatty acid tails
of phospholipids. They would also be poor signaling molecules.
,MCAT Biology Practice Questions and
answers
Peptide hormones like insulin and growth hormone interact with integral protein
receptors in cell membranes. These hormones can be considered peripheral
membrane proteins.
Pulmonary edema occurs when fluid builds up in the interstitium between the
pulmonary capillaries and the alveoli, and eventually enters the alveoli. How do
you decrease the risk of pulmonary edema?
A. Decrease hydrostatic pressure and increase osmotic pressure
B. Decrease hydrostatic pressure and decrease osmotic pressure
C. Increase hydrostatic pressure and decrease osmotic pressure
D. Increase hydrostatic pressure and increase osmotic pressure - Decrease
hydrostatic pressure and increase osmotic pressure
Hydrostatic pressure is the pressure a liquid exerts on its container, and reflects
the volume of liquid in a space.
Osmotic pressure is the pressure required to prevent movement across a
semipermeable membrane, and reflects the protein content of the blood.
, MCAT Biology Practice Questions and
answers
To decrease the risk of pulmonary edema, hydrostatic pressure exerted by the
fluid must decrease, and osmotic pressure exerted on the fluid must increase.
At what point does crossing over between sister chromatids occur?
A. During anaphase I of meiosis
B. During prophase I of meiosis
C. During anaphase II of meiosis
D. During prophase II of meiosis - During prophase I of meiosis
Crossing over is a form of genetic recombination in which homologous
chromosomes pair up and exchange pieces of their genetic material. Crossing over
occurs in prophase I of meiosis, and is often referred to as synapsis. However,
crossing over occurs between homologous chromosomes, and not between the
sister chromatids of an individual chromosome. Sister chromatids are identical
pieces of DNA joined at the centromere to make up one chromosome.
Your trachea have short hair-like cell process that move the mucus. What is the
name of these hair like structures and which cytoskeletal elements form them?
