BIOLl 1107l Examl 4l l Principlesl ofl

BIOLl 1107l Examl 4l –l Principlesl ofl Biologyl Il (Latestl 2026/l 2027l Update)l Guide|l 100%l Verifiedl Questionsl &l Answersl |l Gradel A

Q:l Thresholdl Potential

Answer:

Thel membranel potentiall thatl willl triggerl anl actionl potentiall inl al neuronl orl otherl excitablel cell.

Q:l Excitablel Membranes

Answer:

Al plasmal membranel thatl isl capablel ofl generatingl anl actionl potential.l Neurons,l musclel cells,l andl somel otherl cellsl havel excitablel membranes.

Q:l Voltage-Gatedl Channels

Answer:

Anl ionl channell thatl opensl orl closesl inl responsel tol al changel inl membranel voltage.

Q:l Voltagel Clamping

Answer:

Al techniquel forl imposingl al constantl membranel potentiall onl al cell.l Widelyl usedl tol investigatel ionl channels.

Q:l Patchl Clamping 1 / 4

Answer:

Al techniquel forl studyingl thel electricall currentsl thatl flowl throughl individuall ionl channelsl byl applyingl thel openl tipl ofl al microl electrodel tol al tinyl patchl ofl membrane.

Q:l Positivel Feedback

Answer:

Al physiologicall mechanisml inl whichl al changel inl somel variablel stimulatesl al responsel thatl increasesl thel change.l Relativelyl rarel inl organismsl butl importantl inl generationl ofl anl actionl potential.

Q:l Neurotoxins

Answer:

Anyl substancel thatl specificallyl destroysl orl blocksl thel normall functioningl ofl neurons.

Q:l Refractoryl State

Answer:

Nol longerl respondingl tol stimulil thatl previouslyl elicitedl al response.l Anl examplel isl thel tendencyl ofl voltage-gatedl sodiuml channelsl tol bel lessl likelyl tol reopenl immediatelyl afterl theyl havel closed.

Q:l Oligodendrocytes

Answer:

Al typel ofl gliall celll thatl wrapsl aroundl axonsl ofl somel neuronsl inl thel vertebrall centrall nervousl system,l formingl al myelinl sheathl thatl providesl electricall insulation.

Q:l Schwannl Cells

Answer: 2 / 4

Al typel ofl gliall celll thatl wrapsl aroundl axonsl ofl somel neuronsl inl thel vertebratel peripherall nervousl system,l formingl al myelinl sheathl thatl providesl electricall insulation.

Q:l Glia

Answer:

Collectivel terml forl severall typesl ofl cellsl inl nervousl tissuel thatl arel notl neuronsl andl dol notl conductl electricall signalsl butl performl otherl functions,l suchl asl providingl support,l nourishment,l orl electricall insulation.

Q:l Myelinl Sheath

Answer:

Multiplel layerl ofl myelin,l derivedl froml thel celll membranesl ofl certainl gliall cells,l wrappedl aroundl thel axonl ofl al neuronl andl providingl electricall insulation.

Q:l Nodel ofl Ranvier

Answer:

Onel ofl thel periodicl gapsl inl thel myelinl sheathl ofl al neuron'sl axon,l servesl asl al sitel wherel anl actionl potentiall canl bel regenerated.

Q:l Multiplel Sclerosisl (MS)

Answer:

Al humanl autoimmunel diseasel inl whichl thel immunel systeml attacksl thel myelinl sheathsl thatl insulatel thel axonsl ofl neurons.

Q:l Synapses

Answer:

Thel interfacel betweenl twol neuronsl orl betweenl al neuronl andl anl effetel cell.

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Q:l Neurotransmitters

Answer:

Al moleculel thatl transmitsl signalsl froml onel neuronl tol anotherl neuronl orl tol al musclel celll orl al glandl cell.l Examplesl arel acetylcholine,l dopamine,l serotonin,l andl norepinephrine.

Q:l Synapticl Cleft

Answer:

Thel spacel betweenl twol communicatingl nervel cellsl (orl betweenl al neuronl andl effectorl cell)l atl al synapse,l acrossl whichl neurotransmittersl diffuse.

Q:l Synapticl Vesicles

Answer:

Al smalll neurotransmitterl containsl vesiclel insidel thel endl ofl anl axonl thatl releasesl neurotransmittersl intol thel synapticl cleftl byl exocytosis.

Q:l Presynapticl Neuron

Answer:

Al neuronl thatl transmitsl signals,l usuallyl byl releasingl neurotransmitters,l tol anotherl neuronl orl tol al musclel celll orl glandl celll atl al synapse.

Q:l Postsynapticl Neuron

Answer:

Al celll thatl receivesl signals,l usuallyl vial neurotransmitters,l froml al neuronl atl al synapse.

Q:l Ligand-Gatedl Channels

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