Mastering Biology Exam Questions and
Answers
Which of these extracellular signal molecules could diffuse through a plasma membrane
and bind to an intracellular receptor? - Answer -estrogen
A(n) _____ is an example of a signal molecule that can bind to an intracellular receptor
and thereby cause a gene to be turned on or off. - Answer -Steroid
Thyroid hormones bind to _____ receptors. - Answer -intracellular
Which of these is a logical signal transduction pathway? - Answer -A G-protein-linked
receptor activates G protein, which activates phospholipase C, which cleaves a
membrane lipid to form IP3, which binds to a calcium channel on the ER, which opens
to release calcium ions into the cytoplasm, which bind to an intracellular enzyme that
carries out a response.
What role does a transcription factor play in a signal transduction pathway? - Answer -
By binding to DNA it triggers the transcription of a specific gene.
Which of the following, when activated by a signal transduction pathway, moves from
the cytoplasm to the nucleus of a cell? - Answer -Transcription factor
A signal transduction pathway is initiated when a _____ binds to a receptor. - Answer -
signam molecule
Which of these acts as a second messenger? - Answer -Cyclic AMP
Calcium ions that act as second messengers are stored in _____. - Answer -
endoplasmic reticula
_____ catalyzes the production of _____, which then opens an ion channel that
releases _____ into the cell's cytoplasm. - Answer -Phospholipase C ... IP3 .... Ca2+
A protein kinase activating many other protein kinases is an example of _____. -
Answer -Amplification
Which type of hormone is lipid soluble? - Answer -Steroids
, Which molecules determine the tissue specificity of hormones? - Answer -Receptors
True or false? Lipid-insoluble hormones affect their target cells by binding to receptors
inside the cell. - Answer -False
Which of the following statements about lipid-soluble hormones is true? - Answer -They
act by affecting the transcription of genes.
Which of the following is a structure that allows hormone-receptor complexes to bind to
specific DNA sequences? - Answer -Zinc finger
What is the role of cAMP in the signal transduction pathway activated by epinephrine? -
Answer -It binds to and activates protein kinase A, which then phosphorylates other
enzymes.
True or false? For a signal transduction pathway to be activated, hormones must be
present in the bloodstream at very high concentrations. - Answer -False
Vertebrates have two major communication and control systems: the endocrine system
and the nervous system. Choose the correct statement describing the coordination of
these systems. - Answer -Epinephrine functions as a hormone in the endocrine system
and as a neurotransmitter in the nervous system.
Select the correct statement about feedback regulation in endocrine systems. - Answer
-Some homeostatic control systems rely on pairs of negatively regulated hormone
pathways, each counterbalance the other.
A neuron's nucleus is located in its _____. - Answer -cell body
A nerve impulse moves toward a neuron's cell body along _____. - Answer -dendrites
A nerve impulse moves away from a neuron's cell body along____. - Answer -axons
An impulse relayed along a myelinated axon "jumps" from _____ to _____. - Answer -
node of Ranvier ... node of Ranvier
Axons insulated by a(n) _____ are able to conduct impulses faster that those not so
insulated. - Answer -myelin sheath
What type of cell makes up the myelin sheath of a motor neuron? - Answer -Schwann
cells
What part of a neuron relays signals from one neuron to another neuron or to an
effector? - Answer -synaptic terminal
Answers
Which of these extracellular signal molecules could diffuse through a plasma membrane
and bind to an intracellular receptor? - Answer -estrogen
A(n) _____ is an example of a signal molecule that can bind to an intracellular receptor
and thereby cause a gene to be turned on or off. - Answer -Steroid
Thyroid hormones bind to _____ receptors. - Answer -intracellular
Which of these is a logical signal transduction pathway? - Answer -A G-protein-linked
receptor activates G protein, which activates phospholipase C, which cleaves a
membrane lipid to form IP3, which binds to a calcium channel on the ER, which opens
to release calcium ions into the cytoplasm, which bind to an intracellular enzyme that
carries out a response.
What role does a transcription factor play in a signal transduction pathway? - Answer -
By binding to DNA it triggers the transcription of a specific gene.
Which of the following, when activated by a signal transduction pathway, moves from
the cytoplasm to the nucleus of a cell? - Answer -Transcription factor
A signal transduction pathway is initiated when a _____ binds to a receptor. - Answer -
signam molecule
Which of these acts as a second messenger? - Answer -Cyclic AMP
Calcium ions that act as second messengers are stored in _____. - Answer -
endoplasmic reticula
_____ catalyzes the production of _____, which then opens an ion channel that
releases _____ into the cell's cytoplasm. - Answer -Phospholipase C ... IP3 .... Ca2+
A protein kinase activating many other protein kinases is an example of _____. -
Answer -Amplification
Which type of hormone is lipid soluble? - Answer -Steroids
, Which molecules determine the tissue specificity of hormones? - Answer -Receptors
True or false? Lipid-insoluble hormones affect their target cells by binding to receptors
inside the cell. - Answer -False
Which of the following statements about lipid-soluble hormones is true? - Answer -They
act by affecting the transcription of genes.
Which of the following is a structure that allows hormone-receptor complexes to bind to
specific DNA sequences? - Answer -Zinc finger
What is the role of cAMP in the signal transduction pathway activated by epinephrine? -
Answer -It binds to and activates protein kinase A, which then phosphorylates other
enzymes.
True or false? For a signal transduction pathway to be activated, hormones must be
present in the bloodstream at very high concentrations. - Answer -False
Vertebrates have two major communication and control systems: the endocrine system
and the nervous system. Choose the correct statement describing the coordination of
these systems. - Answer -Epinephrine functions as a hormone in the endocrine system
and as a neurotransmitter in the nervous system.
Select the correct statement about feedback regulation in endocrine systems. - Answer
-Some homeostatic control systems rely on pairs of negatively regulated hormone
pathways, each counterbalance the other.
A neuron's nucleus is located in its _____. - Answer -cell body
A nerve impulse moves toward a neuron's cell body along _____. - Answer -dendrites
A nerve impulse moves away from a neuron's cell body along____. - Answer -axons
An impulse relayed along a myelinated axon "jumps" from _____ to _____. - Answer -
node of Ranvier ... node of Ranvier
Axons insulated by a(n) _____ are able to conduct impulses faster that those not so
insulated. - Answer -myelin sheath
What type of cell makes up the myelin sheath of a motor neuron? - Answer -Schwann
cells
What part of a neuron relays signals from one neuron to another neuron or to an
effector? - Answer -synaptic terminal
