AP Biology Body Systems
Adjacent neurons with direct (non-neurotransmitter) action potential transfer are said to have electrical synapses, based on the presence of A) tight junctions at their point of contact. B) gap junctions at their point of contact. C) leaky junctions at their point of contact. D) anchoring junctions at their point of contact. E) desmosomes at their point of contact.
B
The following steps refer to various stages in transmission at a chemical synapse. 1. Neurotransmitter binds with receptors associated with the postsynaptic membrane. 2. Calcium ions rush into neuron's cytoplasm. 3. An action potential depolarizes the membrane of the axon terminal. 4. The ligand-gated ion channels open. 5. The synaptic vesicles release neurotransmitter into the synaptic cleft. Which sequence of events is correct? A) 1 → 2 → 3 → 4 → 5 B) 2 → 3 → 5 → 4 → 1 C) 3 → 2 → 5 → 1 → 4 D) 4 → 3 → 1 → 2 → 5 E) 5 → 1 → 2 → 4 → 3
C
ATP hydrolysis directly powers the movement of
Na+ out of cells
Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have
a closed circulatory system
Different body cells can respond differently to the same peptide hormones because
a target cell's response is determined by the components of its signal transduction pathways
Innate immunity is
activated immediately upon infection
In the human disease known as lupus, there is an immune reaction against a patient's own DNA from broken or dying cells, which categorizes lupus as
an autoimmune disease
In a positive-feedback system where hormone A alters the amount of protein X
an increase in A always produces an increase in X
One reason a person might be severely overweight is due to
an undersecretion of thyroxine.
The receptors on T cells and B cells bind to
antigens
Hormone X activates the cAMP second messenger system in its target cells. The greatest response by a cell would come from
applying a molecule of hormone X to the extracellular fluid surrounding the cell
All hormones
are carried to target cells in the blood
Select the pathway that would lead to the activation of cytotoxic T cells
body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface
The body's reaction to PTH (parathyroid hormone), a reduction in plasma levels of calcium, can be opposed by
calcitonin
T cells of the immune system include
cytotoxic and helper cells
The MHC is important in a T cell's ability to
distinguish self from non-self
A chemical signal that has both endocrine and neural roles is
epinephrine
Heart rate will increase in the presence of increased
epinephrine
Dialysis patients, who will have blood withdrawn, dialyzed, then replaced, are always weighed when they enter the facility and then weighed carefully again before they leave, because
even small changes in body weight may signify changes in blood volume and therefore blood pressure `
A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin Bob), even though Jane has previously given blood for one of Bob's needed transfusions, because
even though Jane's blood type is a match to Bob's, her MHC proteins may not be a match
The meshwork that forms the fabric of a blood clot is
fibrin
Antigens are
foreign molecules that trigger the generation of antibodies
Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of
glucagon
Endocrine glands that are sources of steroid hormones
have a very short latency between steroid synthesis and steroid release.
Shortly after ingesting a big plate of carbohydrate-rich pasta, you measure your blood's hormone levels. What results would you expect, compared to before the meal?
high insulin, low glucagon
Oxytocin and antidiuretic hormone are synthesized in the
hypothalamus
The hypothalamus
includes neurosecretory cells that terminate in the posterior pituitary
Aspirin and ibuprofen both
inhibit the synthesis of prostaglandins.
Which hormone is incorrectly paired with its action?
insulin stimulates glycogen breakdown in the liver
Most of the neurons in the human brain are
interneurons
Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates that prolactin
is an evolutionarily conserved hormone
If a person loses a large amount of water in a short period of time, he or she may die from dehydration. ADH can help reduce water loss through its interaction with its target cells in the
kidney
The function of antibodies is to
mark pathogenic cells for destruction
Winter hibernation and spring reproduction in bears are cued by seasonal changes in the secretion of
melatonin from the pineal gland.
Secondary immune responses upon a second exposure to a pathogen are due to the activation of
memory cells
The increased contraction of the human uterus during labor and delivery is at least partially due to the actions of
oxytocin
Adaptive immunity depends on
pathogen- specific recognition
In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are
prolactin and oxytocin
Yearly vaccination of humans for influenza viruses is necessary because
rapid mutation in flu viruses alters the surface proteins in infected host cells
The operation of the sodium potassium pump moves
sodium ions out of the cell and potassium ions into the cell
Vasoconstriction in the gut is a likely response when an individual is
stressed and secreting stress hormones
The point of connection between two communicating neurons is called
synapse
A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone's
target cell
Fight-or-flight reactions include activation of
the adrenal medulla, leading to increased secretion of epinephrine
Melatonin is secreted by
the pineal gland during the night.
A key part of the humoral immune response is
the production of antibodies by plasma cells
When the beta cells of the pancreas release insulin into the blood
the skeletal muscles and the adipose cells take up glucose at a faster rate.
Iodine is added to table salt to help prevent deficiencies of an essential mineral needed for the proper function of the
thyroid glands.
A tropic hormone from the anterior pituitary gland regulates the secretion of
thyroxine.
Which of the following is the correct sequence of blood flow in reptiles and mammals?
vena cava, right atrium, right ventricle, pulmonary circuit