MCAT Biology Practice Questions
Are fungi capable of asexual or sexual reproduction? - ANS-BOTH
Are peptide hormones water soluble? - ANS-Yes. They dissolve in the blood. The blood
contains them to their goal tissue.
Are protists euk or prokaryotes? - ANS-Eukaryotes
Are steroids polar or nonpolar? - ANS-Nonpolar.
Are viruses living organisms? - ANS-No
As a protein is translated, in which do they cross once they're inside the ER lumen? -
ANS-Enzymes in the rER attach a small sugar complicated that specifies wherein the protein
will go. Proteins are carried thru delivery vesicles to the golgi for
organizes/modifies/concentrates proteins.
As you move down and up the loop of henle, describe where it is turns into extra
concentrated, and where extra dilute. - ANS-As you pass down the loop of henle gets extra
focused, but greater dilute as you move up the alternative side.
The factor is to concentrate solute in the medulla, not the filtrate. This prepares the kidney to
provide focused urine.
At the time of beginning, at what degree are woman eggs at? - ANS-Primary oocyte level
At what point is the most commonplace for regulation of protein production? Why? -
ANS-Transcription
Replication occurs less frequently and does not distinguish between genes.
Basophils: What are they, what % of blood are they? Gran or agran? Lifetime? -
ANS-Histamine launch
<1%
Gran
A few hrs - few days
By the time the filtrate gets to the loop of Henle, what's it like? - ANS-The osmolarity of the
filtrate hasn't changed, but the amount of filtrate has been reduced by 80%, and the
consistency of the filtrate has changed.
Can viruses have both DNA and RNA? - ANS-No
Define back mutation. - ANS-The reversion of a mutant to the original phenotype.
,Define forward mutation. - ANS-Any mutation which changes a formerly functional wild
genotype or phenotype to nonfunctional
Define lysogenic cycle. - ANS-Viral nucleic acids become incorporated into host genome
Viral genes may remain inactive indefinitely
Viral genes incorporated into daughter cells
Can become activated to be lytic as a result of stress that damages DNA
Define lytic cycle. - ANS-Viral nucleic acids commandeer host
Create new virions
Lyse the cell to release virions
Define Mendel's 1st Law: Law of Segregation. - ANS-A gene can exist in more than one
form.
Organisms inherit two alleles for each trait.
When gametes are produced (by meiosis), allele pairs separate leaving each cell with a
single allele for each trait.
When the two alleles of a pair are different, one is dominant and the other is recessive.
Define Mendel's 2nd Law: Law of Independent Assortment. - ANS-Allele pairs separate
independently during the formation of gametes. This means that traits are transmitted to
offspring independently of one another.
Define passive diffusion. - ANS-When something moves across the membrane in the
direction of its electrochemical gradient, without the use of a specific channel and without the
expenditure of additional E.
Define saltatory conduction. - ANS-the propagation of action potentials along myelinated
axons from one node of Ranvier to the next node, increasing the conduction velocity of
action potentials without needing to increase the diameter of an axon.
Describe amino acid structure. - ANS-Amino acids have 4 parts attached to the alpha
carbon.
1. The amino group, which is NH2
2. The R group, which is one of 20 choices
3. The Carboxylic acid or C O O
the last thing attached to the Carbon is the Hydrogen.
Describe an action potential. - ANS-1) A stimulus is received by the dendrites of a nerve cell.
This causes the Na+ channels to open. If the opening is sufficient to drive the interior
potential from -70 mV up to -55 mV, the process continues.
Having reached the action threshold, more Na+ channels (sometimes called voltage-gated
channels) open. The Na+ influx drives the interior of the cell membrane up to about +30 mV.
The process to this point is called depolarization.
2) The Na+ channels close and the K+ channels open. Since the K+ channels are much
slower to open, the depolarization has time to be completed. Having both Na+ and K+
channels open at the same time would drive the system toward neutrality and prevent the
creation of the action potential.
,3) With the K+ channels open, the membrance begins to repolarize back toward its rest
potential.
4) The repolarization typically overshoots the rest potential to about -90 mV. This is called
hyperpolarization and would seem to be counterproductive, but it is actually important in the
transmission of information. Hyperpolarization prevents the neuron from receiving another
stimulus during this time, or at least raises the threshold for any new stimulus. Part of the
importance of hyperpolarization is in preventing any stimulus already sent up an axon from
triggering another action potential in the opposite direction. In other words, hyperpolarization
assures that the signal is proceeding in one direction.
5) After hyperpolarization, the Na+/K+ pump eventually brings the membrane back to its
resting state of -70 mV .
Describe bile. - ANS-Synthesized in the liver.
Stored in the gallbladder.
Secreted via the pancreatic duct.
Emulsifies fat - physical process.
Describe complementarity. - ANS-In complimentary gene activity, the genes actually work
together, for example, to make a complete protein. The gene that makes the alpha
hemoglobin polypeptide and the gene that makes the beta hemoglobin polypeptide work
together to make a complete hemoglobin protein.
Describe epistasis. - ANS-In epistasis, one gene "hides" the effects of another gene, much
the way one allele hides the affect of its homologous allele in dominance. In rats, B makes
black fur and b makes brown fur, but the E gene determines whether any pigment woujld be
laid down at all; without an E allele, the fur is white. So, eeBB and eebb would both have
white fur; EeBB would have black fur and Eebb would have brown fur...
Describe how a preprohormone is processed to a hormone, and important locations as this
happens. - ANS-Preprohorm => prohormone, cleaved into ER lumen
Prohorm => horm, cleaved inside golgi app and possibly changed w/carbs
Describe ingestion, digestion, and absorption. - ANS-Ingestion - acquirement of meals
Digestion - mechanical and chemical degradation of the food into absorbable nutrients
Absorption - takes place while the nutrients pass the epithelial layer and input the cells and
blood
Describe spermatogenesis. - ANS-PMATx2
Describe the chemical structure of glucose - ANS-1) Aldehyde
2) Has 4 chiral carbons
3) Fischer - R, L, R, R
four) 6 membered ring wherein one of the ring participants is oxygen
5) C1 - anomeric carbon
Describe the functional anatomy of the ear. - ANS-Outer - Pinna, canal
Middle - Malleus, Incus, Stapes (Transfer sound E from ear drum to internal ear at oval
window)
, Inner - cochlea (transduces sound to el stimulation and sends to brain), semicircular canals
(monitor position, orientation, and acceleration of head).
Describe the functional anatomy of the eye. - ANS-Lens - focuses photographs on retina
Retina - located at back, composed of rods(no colour) and cones (shade)
Iris - group of clean muscle tissue developing establishing to eye
Describe the overall characteristics of a steroid hormone. - ANS-Lipid soluble, ringed
structures
Describe the existence cycle of a virus. - ANS-1) Virus connects with precise glycoprotein
receptor on host mobile.
2) Nucleic acid injected into bacterium/Virus taken into animal mobile by using endocytosis
three) Lysosome attaches to phagosome, capsid released into cytosol via exocytosis, earlier
than lysosome can digest virus.
Four) Lytic or lysogenic
Describe the main functions of the sgements of the small gut? - ANS-Duodenum - Digestion
Jejunum, Illeum - Absorption
Describe the ribosome of a micro organism. - ANS-70s =
50s large
30s small
Describe the ribosome of an animal. - ANS-80s =
60s
40s
Describe the signaling related to a steroid hormone. - ANS-Steroid hormones certain to
provider proteins in the blood detach from the service protein, diffuse thru the membrane,
and bind to another carrier protein inside the cytosol. The 2d provider takes them into the
nucleus, wherein they act at the extent of trx.
Describe the signaling cascade associated w/peptide hormones. - ANS-1) Peptide hormone
attaches to floor receptor.
2) Membrane sure receptor activates a G protein.
3) This stimulates/inhibits another membrane certain protein: adenylate cyclase.
4) Adenylate cyclase will increase the cAMP attention
5) cAMP activates a protein kinase which PO4s or dePO4s and enzyme
Describe the specialised muscle of the SA node. - ANS-Modified cardiac muscle cells that
spontaneously settlement at a charge quicker than the nl heartbeat. The SA node is
innervated by means of the vagus nerve. The vagus nerve is PS and slows it down.
Describe the shape of skeletal muscle. - ANS-...
Describe the shape of the NS in terms of what is afferent vs efferent. - ANS-SAME DAVE
Sensory Afferent
Are fungi capable of asexual or sexual reproduction? - ANS-BOTH
Are peptide hormones water soluble? - ANS-Yes. They dissolve in the blood. The blood
contains them to their goal tissue.
Are protists euk or prokaryotes? - ANS-Eukaryotes
Are steroids polar or nonpolar? - ANS-Nonpolar.
Are viruses living organisms? - ANS-No
As a protein is translated, in which do they cross once they're inside the ER lumen? -
ANS-Enzymes in the rER attach a small sugar complicated that specifies wherein the protein
will go. Proteins are carried thru delivery vesicles to the golgi for
organizes/modifies/concentrates proteins.
As you move down and up the loop of henle, describe where it is turns into extra
concentrated, and where extra dilute. - ANS-As you pass down the loop of henle gets extra
focused, but greater dilute as you move up the alternative side.
The factor is to concentrate solute in the medulla, not the filtrate. This prepares the kidney to
provide focused urine.
At the time of beginning, at what degree are woman eggs at? - ANS-Primary oocyte level
At what point is the most commonplace for regulation of protein production? Why? -
ANS-Transcription
Replication occurs less frequently and does not distinguish between genes.
Basophils: What are they, what % of blood are they? Gran or agran? Lifetime? -
ANS-Histamine launch
<1%
Gran
A few hrs - few days
By the time the filtrate gets to the loop of Henle, what's it like? - ANS-The osmolarity of the
filtrate hasn't changed, but the amount of filtrate has been reduced by 80%, and the
consistency of the filtrate has changed.
Can viruses have both DNA and RNA? - ANS-No
Define back mutation. - ANS-The reversion of a mutant to the original phenotype.
,Define forward mutation. - ANS-Any mutation which changes a formerly functional wild
genotype or phenotype to nonfunctional
Define lysogenic cycle. - ANS-Viral nucleic acids become incorporated into host genome
Viral genes may remain inactive indefinitely
Viral genes incorporated into daughter cells
Can become activated to be lytic as a result of stress that damages DNA
Define lytic cycle. - ANS-Viral nucleic acids commandeer host
Create new virions
Lyse the cell to release virions
Define Mendel's 1st Law: Law of Segregation. - ANS-A gene can exist in more than one
form.
Organisms inherit two alleles for each trait.
When gametes are produced (by meiosis), allele pairs separate leaving each cell with a
single allele for each trait.
When the two alleles of a pair are different, one is dominant and the other is recessive.
Define Mendel's 2nd Law: Law of Independent Assortment. - ANS-Allele pairs separate
independently during the formation of gametes. This means that traits are transmitted to
offspring independently of one another.
Define passive diffusion. - ANS-When something moves across the membrane in the
direction of its electrochemical gradient, without the use of a specific channel and without the
expenditure of additional E.
Define saltatory conduction. - ANS-the propagation of action potentials along myelinated
axons from one node of Ranvier to the next node, increasing the conduction velocity of
action potentials without needing to increase the diameter of an axon.
Describe amino acid structure. - ANS-Amino acids have 4 parts attached to the alpha
carbon.
1. The amino group, which is NH2
2. The R group, which is one of 20 choices
3. The Carboxylic acid or C O O
the last thing attached to the Carbon is the Hydrogen.
Describe an action potential. - ANS-1) A stimulus is received by the dendrites of a nerve cell.
This causes the Na+ channels to open. If the opening is sufficient to drive the interior
potential from -70 mV up to -55 mV, the process continues.
Having reached the action threshold, more Na+ channels (sometimes called voltage-gated
channels) open. The Na+ influx drives the interior of the cell membrane up to about +30 mV.
The process to this point is called depolarization.
2) The Na+ channels close and the K+ channels open. Since the K+ channels are much
slower to open, the depolarization has time to be completed. Having both Na+ and K+
channels open at the same time would drive the system toward neutrality and prevent the
creation of the action potential.
,3) With the K+ channels open, the membrance begins to repolarize back toward its rest
potential.
4) The repolarization typically overshoots the rest potential to about -90 mV. This is called
hyperpolarization and would seem to be counterproductive, but it is actually important in the
transmission of information. Hyperpolarization prevents the neuron from receiving another
stimulus during this time, or at least raises the threshold for any new stimulus. Part of the
importance of hyperpolarization is in preventing any stimulus already sent up an axon from
triggering another action potential in the opposite direction. In other words, hyperpolarization
assures that the signal is proceeding in one direction.
5) After hyperpolarization, the Na+/K+ pump eventually brings the membrane back to its
resting state of -70 mV .
Describe bile. - ANS-Synthesized in the liver.
Stored in the gallbladder.
Secreted via the pancreatic duct.
Emulsifies fat - physical process.
Describe complementarity. - ANS-In complimentary gene activity, the genes actually work
together, for example, to make a complete protein. The gene that makes the alpha
hemoglobin polypeptide and the gene that makes the beta hemoglobin polypeptide work
together to make a complete hemoglobin protein.
Describe epistasis. - ANS-In epistasis, one gene "hides" the effects of another gene, much
the way one allele hides the affect of its homologous allele in dominance. In rats, B makes
black fur and b makes brown fur, but the E gene determines whether any pigment woujld be
laid down at all; without an E allele, the fur is white. So, eeBB and eebb would both have
white fur; EeBB would have black fur and Eebb would have brown fur...
Describe how a preprohormone is processed to a hormone, and important locations as this
happens. - ANS-Preprohorm => prohormone, cleaved into ER lumen
Prohorm => horm, cleaved inside golgi app and possibly changed w/carbs
Describe ingestion, digestion, and absorption. - ANS-Ingestion - acquirement of meals
Digestion - mechanical and chemical degradation of the food into absorbable nutrients
Absorption - takes place while the nutrients pass the epithelial layer and input the cells and
blood
Describe spermatogenesis. - ANS-PMATx2
Describe the chemical structure of glucose - ANS-1) Aldehyde
2) Has 4 chiral carbons
3) Fischer - R, L, R, R
four) 6 membered ring wherein one of the ring participants is oxygen
5) C1 - anomeric carbon
Describe the functional anatomy of the ear. - ANS-Outer - Pinna, canal
Middle - Malleus, Incus, Stapes (Transfer sound E from ear drum to internal ear at oval
window)
, Inner - cochlea (transduces sound to el stimulation and sends to brain), semicircular canals
(monitor position, orientation, and acceleration of head).
Describe the functional anatomy of the eye. - ANS-Lens - focuses photographs on retina
Retina - located at back, composed of rods(no colour) and cones (shade)
Iris - group of clean muscle tissue developing establishing to eye
Describe the overall characteristics of a steroid hormone. - ANS-Lipid soluble, ringed
structures
Describe the existence cycle of a virus. - ANS-1) Virus connects with precise glycoprotein
receptor on host mobile.
2) Nucleic acid injected into bacterium/Virus taken into animal mobile by using endocytosis
three) Lysosome attaches to phagosome, capsid released into cytosol via exocytosis, earlier
than lysosome can digest virus.
Four) Lytic or lysogenic
Describe the main functions of the sgements of the small gut? - ANS-Duodenum - Digestion
Jejunum, Illeum - Absorption
Describe the ribosome of a micro organism. - ANS-70s =
50s large
30s small
Describe the ribosome of an animal. - ANS-80s =
60s
40s
Describe the signaling related to a steroid hormone. - ANS-Steroid hormones certain to
provider proteins in the blood detach from the service protein, diffuse thru the membrane,
and bind to another carrier protein inside the cytosol. The 2d provider takes them into the
nucleus, wherein they act at the extent of trx.
Describe the signaling cascade associated w/peptide hormones. - ANS-1) Peptide hormone
attaches to floor receptor.
2) Membrane sure receptor activates a G protein.
3) This stimulates/inhibits another membrane certain protein: adenylate cyclase.
4) Adenylate cyclase will increase the cAMP attention
5) cAMP activates a protein kinase which PO4s or dePO4s and enzyme
Describe the specialised muscle of the SA node. - ANS-Modified cardiac muscle cells that
spontaneously settlement at a charge quicker than the nl heartbeat. The SA node is
innervated by means of the vagus nerve. The vagus nerve is PS and slows it down.
Describe the shape of skeletal muscle. - ANS-...
Describe the shape of the NS in terms of what is afferent vs efferent. - ANS-SAME DAVE
Sensory Afferent
