MCAT BIOLOGY ACTUAL COMPREHENSIVE ALL QUESTIONS
AND ANSWERS SURE A+
✔✔Incomplete Regeneration - ✔✔Newly formed tissue is not identical in structure or
function to the tissue that has been lost or injured.
✔✔Senescence - ✔✔Biological aging, occurs when changes occurring in molecular and
cellular structures accumulate. This usually results in the failure of cells to divide and is
caused by a shortening in the telomeres.
✔✔Telomerase active cell-types - ✔✔Germ cells, fetal cells, tumor cells
Reverse transcriptase that prevents senescence because regenerates telomere
✔✔Fetal Circulation - ✔✔Maternal and fetal blood do not mix. Diffusion is needed to
move nutrients and waste products. Diffusion requires a gradient meaning there needs
to be a higher partial pressure of oxygen in maternal blood than fetal blood.
✔✔Fetal Hemoglobin (HbF) - ✔✔Exhibits greater affinity for oxygen than does maternal
hemoglobin. This assists in the transfer of oxygen into the fetal circulatory system in the
placental-maternal junction
✔✔Fetal Placental Function - ✔✔Structure that provides immune protection to a
developing fetus. Antibodies will cross but maternal oxygen and hemoglobin will not.
✔✔Placenta and Endocrine Functions - ✔✔Structure that supports maternal
maintenance of pregnancy by producing progesterone, estrogen, and human chorionic
gonadotropin (hCG).
✔✔Oxygenation of Fetal Blood - ✔✔Oxygenation occurs at the placenta, rather than in
the fetal lungs.
✔✔Differences in Fetal and Adult Circulation - ✔✔Lungs and liver do not serve
significant functions. Gas exchange occurs at the placenta. Mother's liver does
detoxification and metabolism. Nutrient and waste exchange occurs at the placenta.
✔✔Shunts - ✔✔Vascular passages that direct blood away from the developing fetal
lungs and liver.
✔✔Foramen Ovale - ✔✔One-way valve that connects the right atrium to the left atrium.
Blood enters the right atrium via the inferior vena cava and flows into the left atrium,
instead of the right ventricle, thus blood is pumped through aorta into systemic
circulation directly. Unlike in the adult, the fetal blood pressure is higher in the right side
of the heart instead of the left, which helps to push blood through foramen ovale to the
left atrium.
,✔✔Ductus Arteriosus - ✔✔Shunts leftover blood from the pulmonary artery to the aorta.
The pressure differential between right and left sides of heart pushes blood from right to
left side into aorta
✔✔Ductus Venosus - ✔✔Bypasses the liver, shunts blood returning from the placenta
via the umbilical vein directly to the inferior vena cava.
✔✔First Trimester - ✔✔Stage of pregnancy. Major organs develop, cartilaginous
skeleton begins to harden into bone, most of the organs have formed, brain is fairly
developed, and the embryo is called a fetus.
✔✔Second Trimester - ✔✔Stage of Pregnancy. Tremendous growth, it moves within the
amniotic fluid, facial appearance takes place, toes and fingers elongate.
✔✔Third Trimester - ✔✔Stage of Pregnancy. Rapid growth and further brain
development. Antibodies are transported by highly selective active transport from the
mother to the fetus for protection against foreign matter. Fetus growth and movement
slows
✔✔Parturition - ✔✔A synonym for vaginal childbirth
✔✔Prostaglandins - ✔✔A group of bioactive, hormone-like chemicals derived from fatty
acids that have a wide variety of biological effects including roles in inflammation,
platelet aggregation, vascular smooth muscle dilation and constriction, cell growth,
protection of from acid in the stomach, and parturition.
✔✔Neurons - ✔✔A cell that conducts electrical impulses
✔✔the functional unit of the nervous system - ✔✔
✔✔Cell Body - ✔✔Portion of the neuron where the nucleus, endoplasmic reticulum, and
ribosomes are located
✔✔also known as the soma. - ✔✔
✔✔Soma - ✔✔Neuron cell body
✔✔Dendrites - ✔✔The portion of a neuron that receives stimuli from other cells and
conveys them toward the cell body
✔✔Axon Hillock - ✔✔Transition point between the cell body (soma) and the axon of a
neuron
✔✔the site of action potential initiation - ✔✔
,✔✔Action Potentials - ✔✔An abrupt change in the membrane potential of a nerve or
muscle caused by changes in membrane ionic permeability; results in conduction of an
impulse in nerves or contraction in muscles
✔✔Axon - ✔✔The long fiber of a neuron; it conducts impulses away from the cell body
toward the synapse
✔✔Myelin - ✔✔The white, lipid containing material surrounding the axons of the many
neurons in the central and peripheral nervous systems. Maintains the electric signal
within a neuron and increases speed of conduction in the axon
✔✔Oligodendrocytes - ✔✔Myelin Producing Cells in the Central Nervous System
✔✔Schwann Cells - ✔✔Myelin Producing or (non-myelinating) cells in the peripheral
nervous system
✔✔Nodes of Ranvier - ✔✔Points on a myelinated axon that are not covered by myelin
✔✔Nerve Terminal - ✔✔End of the axon from which neurotransmitter molecules are
released
✔✔also called a synaptic bouton - ✔✔
✔✔Synaptic Bouton (Knob) - ✔✔nerve terminal
✔✔Neurotransmitters - ✔✔A chemical agent released into the synaptic cleft by the
synaptic bouton of a neuron; binds to receptor sites on a post-synaptic neuron or
effector membranes to alter activity
✔✔Synaptic Cleft - ✔✔Space between the neurons into which the terminal portion of an
axon releases neurotransmitters which bind to the dendrites of the postsynaptic neuron
✔✔Synapse - ✔✔The Junction between two neurons into which neurotransmitters are
released
✔✔Nerve - ✔✔A bundle of neurons in PNS
✔✔Sensory Nerve - ✔✔Nerves that carry sensory information
✔✔Motor Nerve - ✔✔Nerves that carry motor information
✔✔Mixed Nerve - ✔✔Nerves that carry both motor and sensory information
, ✔✔Tracts - ✔✔Axons bundled together in the CNS (only carry one type of information)
✔✔Cell bodies of neurons clustered together in CNS are:
In PNS: - ✔✔nuclei=cns
ganglia=pns
✔✔Axon bundles in CNS:
In PNS: - ✔✔Tracts
nerves
✔✔Nuclei - ✔✔The cell bodies of neurons in the same tract in CNS
✔✔Glial Cells - ✔✔Neuroglia
✔✔Neuroglia - ✔✔(Glial Cells) Support cells for neurons; responsible for functions such
as holding neurons in place, supplying neurons with oxygen and nutrients, insulating
neurons from other neurons, destroying pathogens, and removing dead neurons
✔✔Astrocytes - ✔✔a glial cell that nourishes neurons and forms the blood-brain barrier,
which controls the transmission of solutes from the bloodstream into the nervous tissue
-form scaffold of cns
-monitor and maintain ion concentration homeostasis
-lactate release if neurons need energy
-astrocytes help clear out synapses of neurotransmitter (end feet)
✔✔Ependymal Cells - ✔✔glial cells that line the ventricles of the brain and produce
cerebrospinal fluid, which physically supports the brain and serves as a shock absorber
✔✔Microglia - ✔✔phagocytic glial cells that ingest and breakdown waste products and
pathogens in the CNS
✔✔Mylenating glial cells in CNS and PNS? - ✔✔In CNS=oligodendrocytes-derived from
neural stem cells
IN PNS=schwann cells--derived from neural crest cells
✔✔Neuron/glia development in CNS/PNS - ✔✔CNS=neural stem cells
PNS=neural crest cells
✔✔Resting Membrane Potential - ✔✔The electric potential of a cell at rest,
approximately -70mV in most excitable cells.
✔✔Na+/K+ ATPase - ✔✔Sodium Potassium Pump. Pumps out 3 sodium for every 2
potassium pumped in. Maintains gradient resting membrane potential. A greater
AND ANSWERS SURE A+
✔✔Incomplete Regeneration - ✔✔Newly formed tissue is not identical in structure or
function to the tissue that has been lost or injured.
✔✔Senescence - ✔✔Biological aging, occurs when changes occurring in molecular and
cellular structures accumulate. This usually results in the failure of cells to divide and is
caused by a shortening in the telomeres.
✔✔Telomerase active cell-types - ✔✔Germ cells, fetal cells, tumor cells
Reverse transcriptase that prevents senescence because regenerates telomere
✔✔Fetal Circulation - ✔✔Maternal and fetal blood do not mix. Diffusion is needed to
move nutrients and waste products. Diffusion requires a gradient meaning there needs
to be a higher partial pressure of oxygen in maternal blood than fetal blood.
✔✔Fetal Hemoglobin (HbF) - ✔✔Exhibits greater affinity for oxygen than does maternal
hemoglobin. This assists in the transfer of oxygen into the fetal circulatory system in the
placental-maternal junction
✔✔Fetal Placental Function - ✔✔Structure that provides immune protection to a
developing fetus. Antibodies will cross but maternal oxygen and hemoglobin will not.
✔✔Placenta and Endocrine Functions - ✔✔Structure that supports maternal
maintenance of pregnancy by producing progesterone, estrogen, and human chorionic
gonadotropin (hCG).
✔✔Oxygenation of Fetal Blood - ✔✔Oxygenation occurs at the placenta, rather than in
the fetal lungs.
✔✔Differences in Fetal and Adult Circulation - ✔✔Lungs and liver do not serve
significant functions. Gas exchange occurs at the placenta. Mother's liver does
detoxification and metabolism. Nutrient and waste exchange occurs at the placenta.
✔✔Shunts - ✔✔Vascular passages that direct blood away from the developing fetal
lungs and liver.
✔✔Foramen Ovale - ✔✔One-way valve that connects the right atrium to the left atrium.
Blood enters the right atrium via the inferior vena cava and flows into the left atrium,
instead of the right ventricle, thus blood is pumped through aorta into systemic
circulation directly. Unlike in the adult, the fetal blood pressure is higher in the right side
of the heart instead of the left, which helps to push blood through foramen ovale to the
left atrium.
,✔✔Ductus Arteriosus - ✔✔Shunts leftover blood from the pulmonary artery to the aorta.
The pressure differential between right and left sides of heart pushes blood from right to
left side into aorta
✔✔Ductus Venosus - ✔✔Bypasses the liver, shunts blood returning from the placenta
via the umbilical vein directly to the inferior vena cava.
✔✔First Trimester - ✔✔Stage of pregnancy. Major organs develop, cartilaginous
skeleton begins to harden into bone, most of the organs have formed, brain is fairly
developed, and the embryo is called a fetus.
✔✔Second Trimester - ✔✔Stage of Pregnancy. Tremendous growth, it moves within the
amniotic fluid, facial appearance takes place, toes and fingers elongate.
✔✔Third Trimester - ✔✔Stage of Pregnancy. Rapid growth and further brain
development. Antibodies are transported by highly selective active transport from the
mother to the fetus for protection against foreign matter. Fetus growth and movement
slows
✔✔Parturition - ✔✔A synonym for vaginal childbirth
✔✔Prostaglandins - ✔✔A group of bioactive, hormone-like chemicals derived from fatty
acids that have a wide variety of biological effects including roles in inflammation,
platelet aggregation, vascular smooth muscle dilation and constriction, cell growth,
protection of from acid in the stomach, and parturition.
✔✔Neurons - ✔✔A cell that conducts electrical impulses
✔✔the functional unit of the nervous system - ✔✔
✔✔Cell Body - ✔✔Portion of the neuron where the nucleus, endoplasmic reticulum, and
ribosomes are located
✔✔also known as the soma. - ✔✔
✔✔Soma - ✔✔Neuron cell body
✔✔Dendrites - ✔✔The portion of a neuron that receives stimuli from other cells and
conveys them toward the cell body
✔✔Axon Hillock - ✔✔Transition point between the cell body (soma) and the axon of a
neuron
✔✔the site of action potential initiation - ✔✔
,✔✔Action Potentials - ✔✔An abrupt change in the membrane potential of a nerve or
muscle caused by changes in membrane ionic permeability; results in conduction of an
impulse in nerves or contraction in muscles
✔✔Axon - ✔✔The long fiber of a neuron; it conducts impulses away from the cell body
toward the synapse
✔✔Myelin - ✔✔The white, lipid containing material surrounding the axons of the many
neurons in the central and peripheral nervous systems. Maintains the electric signal
within a neuron and increases speed of conduction in the axon
✔✔Oligodendrocytes - ✔✔Myelin Producing Cells in the Central Nervous System
✔✔Schwann Cells - ✔✔Myelin Producing or (non-myelinating) cells in the peripheral
nervous system
✔✔Nodes of Ranvier - ✔✔Points on a myelinated axon that are not covered by myelin
✔✔Nerve Terminal - ✔✔End of the axon from which neurotransmitter molecules are
released
✔✔also called a synaptic bouton - ✔✔
✔✔Synaptic Bouton (Knob) - ✔✔nerve terminal
✔✔Neurotransmitters - ✔✔A chemical agent released into the synaptic cleft by the
synaptic bouton of a neuron; binds to receptor sites on a post-synaptic neuron or
effector membranes to alter activity
✔✔Synaptic Cleft - ✔✔Space between the neurons into which the terminal portion of an
axon releases neurotransmitters which bind to the dendrites of the postsynaptic neuron
✔✔Synapse - ✔✔The Junction between two neurons into which neurotransmitters are
released
✔✔Nerve - ✔✔A bundle of neurons in PNS
✔✔Sensory Nerve - ✔✔Nerves that carry sensory information
✔✔Motor Nerve - ✔✔Nerves that carry motor information
✔✔Mixed Nerve - ✔✔Nerves that carry both motor and sensory information
, ✔✔Tracts - ✔✔Axons bundled together in the CNS (only carry one type of information)
✔✔Cell bodies of neurons clustered together in CNS are:
In PNS: - ✔✔nuclei=cns
ganglia=pns
✔✔Axon bundles in CNS:
In PNS: - ✔✔Tracts
nerves
✔✔Nuclei - ✔✔The cell bodies of neurons in the same tract in CNS
✔✔Glial Cells - ✔✔Neuroglia
✔✔Neuroglia - ✔✔(Glial Cells) Support cells for neurons; responsible for functions such
as holding neurons in place, supplying neurons with oxygen and nutrients, insulating
neurons from other neurons, destroying pathogens, and removing dead neurons
✔✔Astrocytes - ✔✔a glial cell that nourishes neurons and forms the blood-brain barrier,
which controls the transmission of solutes from the bloodstream into the nervous tissue
-form scaffold of cns
-monitor and maintain ion concentration homeostasis
-lactate release if neurons need energy
-astrocytes help clear out synapses of neurotransmitter (end feet)
✔✔Ependymal Cells - ✔✔glial cells that line the ventricles of the brain and produce
cerebrospinal fluid, which physically supports the brain and serves as a shock absorber
✔✔Microglia - ✔✔phagocytic glial cells that ingest and breakdown waste products and
pathogens in the CNS
✔✔Mylenating glial cells in CNS and PNS? - ✔✔In CNS=oligodendrocytes-derived from
neural stem cells
IN PNS=schwann cells--derived from neural crest cells
✔✔Neuron/glia development in CNS/PNS - ✔✔CNS=neural stem cells
PNS=neural crest cells
✔✔Resting Membrane Potential - ✔✔The electric potential of a cell at rest,
approximately -70mV in most excitable cells.
✔✔Na+/K+ ATPase - ✔✔Sodium Potassium Pump. Pumps out 3 sodium for every 2
potassium pumped in. Maintains gradient resting membrane potential. A greater
