AP Biology : AP Biology

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #1 : Nervous System

Which of the following best describes the order of information processing in a neuron?

Possible Answers:

Dendrite, axon, synaptic terminal, cell body

Synaptic terminal, dendrite, cell body, axon

Dendrite, cell body, axon, synaptic terminal

Dendrite, axon, cell body, synaptic terminal

Dendrite, synaptic terminal, cell body, axon

Correct answer:

Dendrite, cell body, axon, synaptic terminal

Explanation:

A neuron receives input from other neurons at the dendrites. Neurotransmitters released by other neurons bind to receptors on the dendrites, which carry the signal to the cell body. The signal is then amplified in the cell body before being transferred to the axon. Once the signal transitions to the axon, it is considered an action potential. The signal eventually reaches the end of the axon, where the synaptic vesicles are located, and stimulates release of neurotransmitters to the next neuron's dendrites.

Example Question #1 : Neural Anatomy

Which of the following is true regarding a neuron?

Possible Answers:

The propagation of signal through a neuron initiates at the dendrite, enters the cell body, and is transmitted from the axon

If an electrical disturbance is large enough in the cell body, the signal generates an action potential at the dendrite

Neurons transmit electrical signals from one cell to the other at the cell body

Neurons contain multiple dendrites and cell bodies

Correct answer:

The propagation of signal through a neuron initiates at the dendrite, enters the cell body, and is transmitted from the axon

Explanation:

Neurons have many dendrites, one cell body, and a single axon with several terminal branches. A dendrite receives an external stimulus and causes an electrical disturbance in the cell body. This electrical disturbance is transmitted to the axon, where an action potential is generated if the stimulus is large enough. The action potential is propagated through the axon and is transmitted to a neighboring neuron at the synapse.

A large enough electrical disturbance will generate an action potential in the axon, but no magnitude of stimulus can create an action potential in the dendrites. Neurons do contain multiple dendrites, but they only contain one cell body and one axon. Finally, neurons transmit electrical signals to other neurons at the synapse, not at the cell body.

Example Question #1 : Neural Anatomy

An electrical synapse uses __________ to transmit electrical signals between neurons.

Possible Answers:

tight junctions

gap junctions

anchoring junctions

desmosomes

Correct answer:

gap junctions

Explanation:

There are two types of synapses: chemical and electrical. Chemical synapses use chemical signals called neurotransmitters to transmit nerve signals between neurons, whereas electrical synapses use electrical signals. These electrical signals are transmitted through a gap junction that connects adjacent neurons. Intercalated discs in cardiac muscle contain gap junctions for the purpose of propagating electrical signals to cause systole.

Example Question #3 : Nervous System

Which of the following cells is found in the peripheral nervous system?

Possible Answers:

Oligodendrocytes

Schwann cells

Astrocytes

Ependymal cells

Microglia

Correct answer:

Schwann cells

Explanation:

While both oligodendrocytes and Schwann cells produce myelin sheaths that insulate nervous system signals, only the Schwann cells are found in the peripheral nervous system.

All other cells listed are found only in the central nervous system. Microglia act as immune cells within the cerebrospinal fluid, since lymphocytes are barred entry by the blood-brain barrier. Astrocytes support the neural cells and provide nutrients. Ependymal cells are responsible for secreting cerebrospinal fluid.

Example Question #6 : Neural Anatomy

Which of the following cells are responsible for speeding up the action potentials along the axon of a neuron?

Possible Answers:

Glial cells

Schwann cells

Astrocytes

Ependymal cells

Myocytes

Correct answer:

Schwann cells

Explanation:

The correct answer is Schwann cells. Schwann cells are cells that produce the myelination present on the outer covering of the axon of the neuron. This lipid-rich material helps facilitate the movement of the action potential along the axon from the axon hillock to the axon terminal branches.

Example Question #1 : Nervous System

The functional units of the nervous system are __________.

Possible Answers:

nephrons

gray matter

 

neurotransmitters

neurons

Correct answer:

neurons

Explanation:

Neurons are the functional unit of the nervous system. Dendrites of the neuron accept incoming action potentials and stimuli, and propagate the signal down the cell axon to stimulate other nearby neurons.

Nephrons are the functional unit of the kidney. Gray matter refers to the regions in the central nervous system where the axonal cell bodies are located, while white matter refers to the regions that contain axons. Neurotransmitters are the particles used to transmit signals across synapses from one neuron to another.

Example Question #401 : Systems Physiology

Which of the following is not part of the peripheral nervous system?

Possible Answers:

Radial nerve

Lumbar Plexus

Tibial nerve

Intercostal nerves

Prefrontal cortex

Correct answer:

Prefrontal cortex

Explanation:

The central nervous system consists of the brain and spinal cord. The peripheral nervous system consists of any nerves or ganglia, not including the brain and spinal cord. The prefrontal cortex is a structure in the cerebrum of the brain, and is thus part of the central nervous system.

General nerves throughout the body are part of the peripheral nervous system.

Example Question #402 : Systems Physiology

What are the vertebral classifications, from superior to inferior?

Possible Answers:

Cervical, lumbar, thoracic, sacral

Cervical, sacral, thoracic, lumbar

Lumbar, thoracic, cervical, sacral

Cervical, thoracic, lumbar, sacral

Thoracic, lumbar, sacral, cervical

Correct answer:

Cervical, thoracic, lumbar, sacral

Explanation:

The spinal cord and vertebrae is broken down into four regions: cervical, thoracic, lumbar, and sacral. There are seven cervical vertebrae, twelve thoracic vertebrae, five lumbar vertebrae, and five sacral vertebrae. Cervical vertebrae are located in the neck, thoracic vertebrae in the trunk or upper back, lumbar vertebrae in the lower back, and sacral vertebrae in the gluteal region. The sacral vertebrae are fused into a single unit known as the sacrum.

Example Question #11 : Nervous System

Which portion of the spinal cord sends sensory information to the brain?

Possible Answers:

Ventral horn

Central canal

Dorsal horn

Lateral horn

Correct answer:

Dorsal horn

Explanation:

The spinal cord consists of functional horns that help send information to the brain, as well as to the parts of the body. The dorsal horns send sensory information to the brain, while the ventral horns contain motor neurons.

Example Question #1 : Understanding The Spinal Cord

What is the correct order of the spinal meninges starting from the outside going inwards towards the spinal cord (superficial to deep)?

Possible Answers:

Arachnoid mater, pia mater, dura mater

Dura mater, pia mater, arachnoid mater

Pia mater, arachnoid mater, dura mater

Dura mater, arachnoid mater, pia mater

Pia mater, dura mater, arachnoid mater

Correct answer:

Dura mater, arachnoid mater, pia mater

Explanation:

The correct order of the spinal meninges from superficial to deep (outside to inside) is dura mater, arachnoid mater, and pia mater. The dura mater is the most outer layer that is closely associated with the skill and vertebral column. Deep to the dura mater is the arachnoid mater, which contains the cerebrospinal found in the subarachnoid space. Underneath the subarachnoid space lies the pia mater, which is very closely associated with the brain and spinal cord. 

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