AP Biology Unit 4 comprehensive
Questions and Answers with Verified
Solutions
Question 1:
What is an antigen?
Answer:
An antigen is any invading material that the immune system needs to
fight (bacteria, viruses, etc)
Question 2:
When a macrophage envelops the antigen, what does it do with it?
Answer:
It destroys the antigen and presents a piece of it on the surface of the
macrophage cell The piece of the antigen will be sensed by the Helper
T-cell, who then activates other immune cells (B cells, Killer T cells, etc)
The macrophage engages in a type of juxtacrine (contact-dependent)
signaling All of the above are true
Question 3:
When the electrical signal travelling down the axon of a neuron reaches
the end of the cell (terminal buds) it is changed to a chemical signal. What
are the chemical messengers (the local regulator) called?
Answer:
Neurotransmitters
,Question 4:
The way neurons communicate with one another is an example of which
type of cellular communication?
Answer:
paracrine
Question 5:
How do opioids (such as morphine and heroin) affect your nervous
system?
Answer:
They mimic the role of endorphines and block neurons from firing
neurotransmitters, effectively
Question 6:
Hormones are used for which type of cellular communication?
Answer:
Endocrine
Question 7:
True or False: Hormones affect many different cells and are used for long
distance communication.
Answer:
True
Question 8:
Which diagram would be an example of juxtacrine communication?
Answer:
Ligand binding to receptor on a cell touching it
, Question 9:
Which diagram would be an example of endocrine communication?
Answer:
Ligand binding to receptor on a cell far away
Question 10:
Which diagram would be an example of paracrine communication?
Answer:
Ligand binding to receptor on a nearby cell
Question 11:
Quorum sensing is used by bacteria to determine the population density
of their species in a local area. (Many bacterial functions would be
ineffective in small numbers—infecting a host organism with a toxin, for
example—and would therefore be a waste of energy and resources to the
bacteria.) Each bacterium produces a ligand. Once the concentration of
that ligand reaches a critical concentration, thus indicating a sufficient
population density for the response to be effective, all bacteria will
respond simultaneously. Which type of communication is this?
Answer:
paracrine
Question 12:
Plants construct channels between cells called plasmodesmata that allow
ligands to move directly from
Answer:
juxtacrine
Questions and Answers with Verified
Solutions
Question 1:
What is an antigen?
Answer:
An antigen is any invading material that the immune system needs to
fight (bacteria, viruses, etc)
Question 2:
When a macrophage envelops the antigen, what does it do with it?
Answer:
It destroys the antigen and presents a piece of it on the surface of the
macrophage cell The piece of the antigen will be sensed by the Helper
T-cell, who then activates other immune cells (B cells, Killer T cells, etc)
The macrophage engages in a type of juxtacrine (contact-dependent)
signaling All of the above are true
Question 3:
When the electrical signal travelling down the axon of a neuron reaches
the end of the cell (terminal buds) it is changed to a chemical signal. What
are the chemical messengers (the local regulator) called?
Answer:
Neurotransmitters
,Question 4:
The way neurons communicate with one another is an example of which
type of cellular communication?
Answer:
paracrine
Question 5:
How do opioids (such as morphine and heroin) affect your nervous
system?
Answer:
They mimic the role of endorphines and block neurons from firing
neurotransmitters, effectively
Question 6:
Hormones are used for which type of cellular communication?
Answer:
Endocrine
Question 7:
True or False: Hormones affect many different cells and are used for long
distance communication.
Answer:
True
Question 8:
Which diagram would be an example of juxtacrine communication?
Answer:
Ligand binding to receptor on a cell touching it
, Question 9:
Which diagram would be an example of endocrine communication?
Answer:
Ligand binding to receptor on a cell far away
Question 10:
Which diagram would be an example of paracrine communication?
Answer:
Ligand binding to receptor on a nearby cell
Question 11:
Quorum sensing is used by bacteria to determine the population density
of their species in a local area. (Many bacterial functions would be
ineffective in small numbers—infecting a host organism with a toxin, for
example—and would therefore be a waste of energy and resources to the
bacteria.) Each bacterium produces a ligand. Once the concentration of
that ligand reaches a critical concentration, thus indicating a sufficient
population density for the response to be effective, all bacteria will
respond simultaneously. Which type of communication is this?
Answer:
paracrine
Question 12:
Plants construct channels between cells called plasmodesmata that allow
ligands to move directly from
Answer:
juxtacrine
