Neurons of the somatic nervous system relay ____.

A) commands to skeletal muscles
B) information from the internal environment to the brain
C) signals to smooth and cardiac muscles
D) signals to adjust digestion
E) signals to adjust the breathing rate

The haploid portion of the life cycle is called the _______________ because it gives rise to haploid gametes by mitosis.

A) archaeplastids
B) archegonia
C) antheridi
D) sporophyte generation
E) gametophyte generation

Impulses that initiate motivation and forethought originate in the ________.

A) postcentral gyrus
B) precentral gyrus
C) prefrontal area
D) association area
E) central sulcus

Adenylyl cyclase catalyzes the reaction in which

A) PIP₂ is split.
B) ATP is converted to cAMP.
C) GTP is converted to GDP.
D) a protein is phosphorylated.
E) calcium ions bind calmodulin.

Proteins are the workhorses of the cell, and responsible for many functions that keep the cell alive. The instructions for how to make each protein are encoded in the cell's DNA. Explain how DNA sequences can serve as instructions for building a protein.

One group of drugs retards heart rate, promotes digestion, contracts the eye pupil, etc. The other group has the opposite effect. These drugs are affecting the

A) motor and sensory nerves.
B) cerebrum and cerebellum, respectively.
C) central and peripheral nervous systems.
D) neurostimulatory and neuroinhibitory synapses.
E) sympathetic and parasympathetic nervous systems.

What forms at a junction between two neurons?

A) myelin sheath
B) synapse
C) node
D) neurotransmitter
E) interneuron

According to _____, two alleles at any locus are distributed into separate gametes during meiosis.

A) the blending theory
B) crossing over
C) Mendel's law of independent assortment
D) Mendel's law of segregation
E) the theory of incomplete dominance

Blood pressure is the

A) product of the stroke volume times heart rate.
B) number of layers of blood in laminar flow models.
C) measure of force blood exerts against blood vessel walls.
D) viscosity of the blood and resistance to blood flow.
E) measure of the volume of the blood.

What axonal characteristic facilitates the propagation of an action potential along a myelinated axon?

A) Voltage-gated Na+ and K+ channels are concentrated in the myelinated axonal segments.
B) Voltage-gated Na+ and K+ channels are concentrated in the unmyelinated axonal segments.
C) Voltage-gated Na+ channels are concentrated in the myelinated axonal segments; voltage-gated K+ channels are concentrated in the unmyelinated axonal segments.
D) Voltage-gated K+ channels are concentrated in the myelinated axonal segments; voltage-gated Na+ channels are concentrated in the unmyelinated axonal segments.
E) Voltage-gated Na+ K+ channels are spread evenly throughout both myelinated and unmyelinated segments.