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MCAT – Biological and Biochemical Foundations Exam 2025/2026 |
Complete Questions with Detailed Answers Latest Update| Graded A+
| Guaranteed Pass
Auxins - ANSWER=A group of plant hormones that play a crucial role in regulating plant growth
and development, primarily by stimulating cell elongation and division, and also influencing root
formation, apical dominance, and fruit development
Hardy-Weinberg Law - ANSWER=A law of population genetics that states that the frequencies of
alleles in a given gene pool do not change over time.
There are five assumptions required for this law to hold true:
- there must be no mutation
- there must be no migration
- there must be no random mating between individuals in the population
- the population must be large.
A population meeting all of these conditions, in which the allele frequency is not changing, is
said to be in Hardy-Weinberg equilibrium.
Hardy-weinberg equation - ANSWER=p^2 + 2pq + q^2 = 1
Where p^2 = the frequency of the GG genotype
Where q^2 = the frequency of the gg genotype
Where 2pq = the frequency of the Gg genotype
,2|Page
Genetic mutation - ANSWER=Refers to any alteration of the DNA sequence of an organism's
genome
Genetic mutations can be (inherited, acquired, or both). - ANSWER=Genetic mutations can be
both inherited or acquired
Somatic mutations (are or are not) passed to offspring - ANSWER=Somatic mutations are not
passed to offspring. They have a major effect on the individual, but not future individuals in a
population
Mutagen - ANSWER=A chemical, physical, or biological agent that interacts with DNA and causes
a mutation.
Some viruses have an envelope. What is an envelope? - ANSWER=a lipid bilayer coating that
surrounds the capsid
autonomic nervous system - ANSWER=Controls involuntary responses of the body like sweating,
blushing, and pupil dilation. Such as the activity of visceral muscles and internal organs and
glands.
Give examples of the organs controlled by the autonomic nervous system (ANS) -
ANSWER=Gallbladder, heart, liver, lungs, etc
Insulin is what type of biomolecule? - ANSWER=Protein; several peptides long and is much
larger than say just one amino acid; Travels through the blood and acts as a chemical signal thus
it is also a hormone
Sympathetic Nervous System (SNS) - ANSWER=Stimulates the "fight or flight" response in the
body. Attention of the body turns to providing glucose to the body (for muscles to get ready to
move), increasing heart rate, dilate the pupils (let in more light), relax the lungs (to increase
oxygenation for the muscles/body), vasoconstriction/vasodilation, and decrease digestion
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Parasympathetic Nervous System (PNS) - ANSWER=Stimulates the "rest and digest" response in
the body. Attention of the body turns to stimulating gall bladder to release bile, stimulation of
the intestines, slowing heartbeat, and constrict lungs.
Acetylcholine (ACh) - ANSWER=a neurotransmitter involved in learning, memory and muscle
movement ;responsible for propagating nerve impulses across the neuromuscular junction
required for skeletal muscle contraction
Simple Diffusion - ANSWER=A form of passive transport because no energy is necessary and no
transmembrane channel is needed
What type of molecules can undergo simple diffusion? - ANSWER=small gases, water (Osmosis)
Facilitated Diffusion is Active or Passive Transport - ANSWER=Passive Transport
Facilitated Diffusion - ANSWER=no energy is necessary because molecules diffuse DOWN their
concentration gradient but a transmembrane channel is needed because the molecule could be
too large or polar for simple diffusion
What type of molecules undergo facilitated diffusion? - ANSWER=ions, lipid-insoluble molecules
Primary active transport - ANSWER=energy is used directly to move a solute AGAINST its
gradient via a transmembrane channel
Secondary active transport - ANSWER=energy is used directly and is stored in an
electrochemical gradient established by primary active transport
, 4|Page
What is a major example of secondary active transport? - ANSWER=Sodium-Calcium Exchanger
(for 3 Na+ ions flowing DOWN their concentration gradient (into the cell) and 1 Ca++ ion out of
the cell
Enveloped viruses can only grow in which type of cells? - ANSWER=animal cells not bacterial
cells
Prion infections can typically occur via... - ANSWER=- inheritance
- spontaneous mutation
- consumption of contaminated tissue (usually brain tissue)
What cellular process can viroids exploit in order to replicate their genomes? - ANSWER=viroids
can alter RNA pol and transcriptional machinery of host cells to replicate their genetic material
what transport mechanism allows for the infection of animal cells by viruses? -
ANSWER=Receptor-mediated endocytosis
Are prion symptoms rapid or do they require a long incubation period? - ANSWER=prion
symptoms require a long incubation period. It can take years or even decades for prion
symptoms to become noticeable
transduction - ANSWER=The transfer of genomic DNA from one bacterium to another by a
lysogenic phage
the ONLY means by which bacteria can increase their genetic diversity
lysogenic phages incorporate their genome into their host's genome.
MCAT – Biological and Biochemical Foundations Exam 2025/2026 |
Complete Questions with Detailed Answers Latest Update| Graded A+
| Guaranteed Pass
Auxins - ANSWER=A group of plant hormones that play a crucial role in regulating plant growth
and development, primarily by stimulating cell elongation and division, and also influencing root
formation, apical dominance, and fruit development
Hardy-Weinberg Law - ANSWER=A law of population genetics that states that the frequencies of
alleles in a given gene pool do not change over time.
There are five assumptions required for this law to hold true:
- there must be no mutation
- there must be no migration
- there must be no random mating between individuals in the population
- the population must be large.
A population meeting all of these conditions, in which the allele frequency is not changing, is
said to be in Hardy-Weinberg equilibrium.
Hardy-weinberg equation - ANSWER=p^2 + 2pq + q^2 = 1
Where p^2 = the frequency of the GG genotype
Where q^2 = the frequency of the gg genotype
Where 2pq = the frequency of the Gg genotype
,2|Page
Genetic mutation - ANSWER=Refers to any alteration of the DNA sequence of an organism's
genome
Genetic mutations can be (inherited, acquired, or both). - ANSWER=Genetic mutations can be
both inherited or acquired
Somatic mutations (are or are not) passed to offspring - ANSWER=Somatic mutations are not
passed to offspring. They have a major effect on the individual, but not future individuals in a
population
Mutagen - ANSWER=A chemical, physical, or biological agent that interacts with DNA and causes
a mutation.
Some viruses have an envelope. What is an envelope? - ANSWER=a lipid bilayer coating that
surrounds the capsid
autonomic nervous system - ANSWER=Controls involuntary responses of the body like sweating,
blushing, and pupil dilation. Such as the activity of visceral muscles and internal organs and
glands.
Give examples of the organs controlled by the autonomic nervous system (ANS) -
ANSWER=Gallbladder, heart, liver, lungs, etc
Insulin is what type of biomolecule? - ANSWER=Protein; several peptides long and is much
larger than say just one amino acid; Travels through the blood and acts as a chemical signal thus
it is also a hormone
Sympathetic Nervous System (SNS) - ANSWER=Stimulates the "fight or flight" response in the
body. Attention of the body turns to providing glucose to the body (for muscles to get ready to
move), increasing heart rate, dilate the pupils (let in more light), relax the lungs (to increase
oxygenation for the muscles/body), vasoconstriction/vasodilation, and decrease digestion
,3|Page
Parasympathetic Nervous System (PNS) - ANSWER=Stimulates the "rest and digest" response in
the body. Attention of the body turns to stimulating gall bladder to release bile, stimulation of
the intestines, slowing heartbeat, and constrict lungs.
Acetylcholine (ACh) - ANSWER=a neurotransmitter involved in learning, memory and muscle
movement ;responsible for propagating nerve impulses across the neuromuscular junction
required for skeletal muscle contraction
Simple Diffusion - ANSWER=A form of passive transport because no energy is necessary and no
transmembrane channel is needed
What type of molecules can undergo simple diffusion? - ANSWER=small gases, water (Osmosis)
Facilitated Diffusion is Active or Passive Transport - ANSWER=Passive Transport
Facilitated Diffusion - ANSWER=no energy is necessary because molecules diffuse DOWN their
concentration gradient but a transmembrane channel is needed because the molecule could be
too large or polar for simple diffusion
What type of molecules undergo facilitated diffusion? - ANSWER=ions, lipid-insoluble molecules
Primary active transport - ANSWER=energy is used directly to move a solute AGAINST its
gradient via a transmembrane channel
Secondary active transport - ANSWER=energy is used directly and is stored in an
electrochemical gradient established by primary active transport
, 4|Page
What is a major example of secondary active transport? - ANSWER=Sodium-Calcium Exchanger
(for 3 Na+ ions flowing DOWN their concentration gradient (into the cell) and 1 Ca++ ion out of
the cell
Enveloped viruses can only grow in which type of cells? - ANSWER=animal cells not bacterial
cells
Prion infections can typically occur via... - ANSWER=- inheritance
- spontaneous mutation
- consumption of contaminated tissue (usually brain tissue)
What cellular process can viroids exploit in order to replicate their genomes? - ANSWER=viroids
can alter RNA pol and transcriptional machinery of host cells to replicate their genetic material
what transport mechanism allows for the infection of animal cells by viruses? -
ANSWER=Receptor-mediated endocytosis
Are prion symptoms rapid or do they require a long incubation period? - ANSWER=prion
symptoms require a long incubation period. It can take years or even decades for prion
symptoms to become noticeable
transduction - ANSWER=The transfer of genomic DNA from one bacterium to another by a
lysogenic phage
the ONLY means by which bacteria can increase their genetic diversity
lysogenic phages incorporate their genome into their host's genome.
