Chapter 25 Thermo-regulation-homestasis, Big Bio Exam

A woman running a marathon collapses at the finish line and is rushed to the hospital. The physicians determine that she has lost a large amount of water and salts from excessive sweating. Which of the following would be an appropriate course of action?

Determine the woman's intracellular fluid levels so that they can provide a fluid replacement therapy that will regain isotonic conditions of salt and water.

Evaluate the following statement: "A neuron's output is the same as its input." a. True b. Mostly true c. Sometimes true, sometimes false d. Mostly false e. False

False

How do feathers help thermoregulation by birds?

Feathers can trap a layer of insulating air next to the skin.

Which sound characteristic can a mammal differentiate that an insect cannot?

Frequency

Which cell layer in the retina produces the action potentials that enter the brain?

Ganglion

Which of the following statements is NOT TRUE about G-protein coupled receptors? a) They generally mediate the action of fast acting neurotransmitters b)They mediate the action of some hormones c) They activate signal proteins called G-proteins d) Histamine can act as a ligand for some G-protein coupled receptors.

A Fast acting neurotransmitter generally activate ion channels since the secondary effect is faster than that of G-protein coupled receptors

Which of the following reactions is catalyzed by a protein kinase? a) the phosphorylation of alcohol groups in protein substrates b) the hydrolysis of phosphate groups in protein substrates c) the phosphorylation of alcohol groups in carbohydrates d) the hydrolysis of phosphate groups in ATP and GTP

A Why? Protein kinase enzymes are responsible for catalyzing phosphorylations of alcohol or phenol groups on protein substrates. The hydrolysis of phosphates is catalyzed by phosphorylases and not by kinases. Carbohydrates contain alcohol functional groups,but these molecules are not proteins and do not act as substrates for protein kinases.

During presynaptic inhibition, which of the following is true? a. A metabotropic response reduces the number of action potentials reaching the synapse. b. A metabotropic response reduces the amount of calcium entering the nerve terminus. c. An ionotropic response reduces the number of action potentials reaching the synapse. d. An ionotropic response reduces the amount of calcium entering the nerve terminus. e. None of the above

A metabotropic response reduces the amount of calcium entering the nerve terminus.

5. The effect of a sending neuron on a receiving neuron is typically greater when ________ neurotransmitters bind to the receiving neuron and the synapse is ________ the base of the receiving cell's axon. A) more; close to B) fewer; close to C) more; far from D) fewer; far from

A) more; close to

7. Which of the following results from stimulation by the sympathetic nervous system? A) release of glucose from the liver B) decreased heart rate C) stimulation of the digestive organs D) constriction of the bronchi

A) release of glucose from the liver - glucose release from the liver into the blood provides quick energy for "fight"

3. Ras A. is a G protein. B. is always active in normal cells. C. is a protein kinase. D. is a receptor. E. is active in the nucleus.

A. is a G protein.

Which of the following is not a G-protein coupled receptor? a) the muscarinic receptor b) the glycine receptor c) the adrenergic receptor d) the glutamate receptor

B The glycine receptor is an ion channel.

Which of the following is NOT a typical messenger for a tyrosine kinase linked receptor? a) insulin b) acetylcholine c) growth factors d) cytokines

B Why? Acetylcholine is a neurotransmitter that activates two types of cholinergic receptor, one of which is an ion channel and the other a G-protein coupled receptor. The other options are hormones that can catalyze various types of tyrosine kinase linked receptors.

Which of the following pairs of receptors illustrate convergent evolution? a) the D2 and D3-dopaminergic receptor subtypes b) the D4 and D5-dopaminergic receptor subtypes c) the B1 and B2-adrenoceptor subtypes d) the M3 and M5-muscarinic receptor subtypes

B Why? Both these receptors bind dopamine, but they have evolved from different branches of the evolutionary tree. The other pairings are examples of divergent evolution since they have evolved from the same branch.

Which of the following is NOT a neurotransmitter? a) acetylcholine b) cyclic AMP c) noradrenaline d) dopamine

B Why? Cyclic AMP is a secondary messenger that is formed 'downstream' of a receptor activated process.

Which of the following statements is TRUE regarding intracellular receptors? a) They consist of three protein subunits. b) They contain a ligand binding site near the C-terminal end. c) They contain a binding region for DNA near the N-terminal end d) They are activated by hydrophobic molecules which are synthesized within the cell.

B Why? Intracellular receptors are single proteins. They contain a binding region for DNA near the middle of the protein and they are activated by hydrophobic molecules which are extracellular messengers and cross the cell membrane to reach their target.

1. Which of the following statements regarding the nervous system is true? A) Sensory neurons convey signals from the CNS to sensory receptors. B) Motor neurons convey signals from the CNS to effector cells. C) The PNS is composed entirely of nerves. D) The CNS and the brain are the same thing.

B) Motor neurons convey signals from the CNS to effector cells. - Sensory input is the conduction of signals from sensory receptors through the PNS to the CNS - Integration in the brain and spinal cord is the analysis and interpretation of the sensory signals and the formulation of appropriate responses (CNS) - Motor output is the conduction of signals from the integration centers through the PNS to effector cells which perform the body's responses

3. Multiple sclerosis results from an autoimmune disease that primarily involves A) destruction of the hippocampus. B) destruction of the myelin sheath. C) destruction of regions of the motor cortex. D) deterioration of parts of the spinal cord.

B) destruction of the myelin sheath. - MS casuses the gradual destruction of myelin sheaths by the individual's own immmune system - Alzheimer's disease results from destruction of the hippocampus - Parkinson's disease results from the destruction of regions of the motor cortex

4. Action potentials relay different intensities of information due to the A) amplitude of action potentials relative to the strength of the stimulus. B) frequency of action potentials relative to the strength of the stimulus. C) duration of action potentials relative to the strength of the stimulus. D) shape of action potentials relative to the strength of the stimulus.

B) frequency of action potentials relative to the strength of the stimulus.

10. Our biological clock, which regulates the sleep-wake cycle, is housed within the A) cerebrum. B) hypothalamus. C) cerebellum. D) brainstem.

B) hypothalamus. - Controls pituitary gland; serves as biological clock - Cerebrum plays major role in memory, learning, speech, emotions - Cerebellum coordinates body movements; plays a role in learning and in remembering motor responses - Brainstem conducts data to and from other brain centers

2. The functional unit of the nervous system is the A) cell body. B) neuron. C) axon. D) synapse.

B) neuron.

11. When the human brain's normal electrical activity is suddenly altered, a seizure can result. Seizures cause several behavioral and physical complications such as sudden mood changes, muscle spasms, or uncontrollable body shaking. Seizure impulses often start in one hemisphere of the brain and travel to the other. Which of the following surgical treatments would reduce the severity of seizures? A) severing the suprachiasmatic nucleus so that the patient's biological clock has altered circadian rhythms B) severing the corpus callosum so that the brain has diminished ability to send messages between the two cerebral hemispheres C) severing the parietal lobe so that speech capabilities are diminished D) stimulating the cerebrum to allow the retention of short-term memory capabilities

B) severing the corpus callosum so that the brain has diminished ability to send messages between the two cerebral hemispheres

The acetylcholine receptor is an example of a(n) _______ receptor, the insulin receptor an example of a(n) _______ receptor, and the epinephrine receptor an example of a(n) _______ receptor. A. G protein-linked; protein kinase; ion channel B. ion channel; protein kinase; G protein-linked C. ion channel; G protein-linked; protein kinase D. protein kinase: ion channel; G protein-linked E. protein kinase; G protein-linked; ion channel

B. ion channel; protein kinase; G protein-linked

6. Nitric oxide (NO) A. can be a second messenger. B. is a participant in some signal transduction pathways. C. directly relaxes smooth muscle. D. directly activates a Ca2+ channel in the endoplasmic reticulum. E. stimulates cAMP synthesis.

B. is a participant in some signal transduction pathways.

4. Gap junctions A. allow large molecules and ions to pass rapidly between cells. B. permit metabolic cooperation among linked cells. C. are formed by the peripheral membrane protein connexin. D. are present in many copies per cell. E. contain membrane lined bridges.

B. permit metabolic cooperation among linked cells.

Which of the following statements is TRUE regarding the DNA binding region of intracellular receptors? a) It contains five cysteine residues b) Four cysteine residues are involved in binding two zinc ions c) It identifies particular nucleotide sequences in DNA d) The DNA binding regions is known as having 'thiol fingers'

C Why? The DNA binding region of intracellular receptors contains 9 cysteine residues, 8 of which are involved in binding 2 zinc ions. The DNA binding region is known as the zinc finger domains.

Which of the following statements is true about a tyrosine kinase linked receptor? a) It is situated in the cytoplasm b) the N-terminal chain in intracellular c) The ligand binding site is in the N-terminal chain d) It has two hydrophobic transmembrane regions

C Why? The receptor is situated in the cell membrane. The N-terminal chain is extracellular and this is where the ligand binding site is. There is only one hydrophobic transmembrane region.

Which of the following statements is NOT TRUE about neurotransmitters? a) neurotransmitters are released by nerves b) neurotransmitters are required to carry a 'message' from a nerve to a target cell c) neurotransmitters have significant distances to cover to reach their target cells d) neurotransmitters bind to receptors on target cells

C Why? The synaptic gap between a nerve and its target cell is very small and so neurotransmitters do not have a huge distance to travel to reach their target receptor.

Which of the following pairs of receptors are likely to show the greatest structural similarity? a) the dopamine receptor subtypes D3 and D5 b) the M2 muscarinic receptor and the B2-adrenergic receptor c) the H2 histamine receptor and the a1-adrenoceptor d) the H1 histamine receptor and the B2-adrenoceptor

C Why? These receptors are closely related on the evolutionary tree of G-protein coupled receptors. The other pairings are more distantly related.

8. The enteric division of the autonomic nervous system consists of neurons in the digestive tract, the gallbladder, and the A) heart. B) lymphatic system. C) pancreas. D) thyroid gland.

C) pancreas.

6. The autonomic nervous system A) integrates sensory inputs to the brain. B) carries signals to and from skeletal muscles. C) regulates the internal environment of the body. D) is part of the central nervous system.

C) regulates the internal environment of the body. - Motor system carries signals to and from skeletal muscles - Parasympathetic division "rest and digest" - Sympathetic division "fight or flight" - Enteric division controls the digestive system

Which of the following signal molecules would most likely have a cytoplasmic receptor? A. A highly charged small molecule B. A polypeptide C. A small nonpolar molecule D. A phospholipid E. A polynucleotide

C. A small nonpolar molecule

Calmodulin binds to _______ and becomes activated. a. Na+ b. G protein c. Ca2+ d. protein kinase C e. adenylyl cyclase

Ca2+

Which of the following is most directly responsible for exocytosis of synaptic vesicles? a. Cl- b. Na+ c. Acetylcholine d. K+ e. Ca2+

Ca2+

Which of the following statements is NOT TRUE about a ligand-gated ion channel receptor? a) Ligand-gated ion channel receptors are present in the cell membrane b) Neurotransmitters can act as the chemical messengers for ligand-gated ion channels c) Ligand-gated ion channels consist of five glycoproteins d) Differences in membrane potential affect whether ligand-gated ion channel receptor open or close.

D Why? Ligand-gated ion channels are controlled by ligand and not by the membrane potential. Voltage-gated ion channels are controlled by membrane potential.

Which of the following statements is true about a G-protein coupled receptor? a) It contains five transmembrane hydrophobic sections. b) There are more extracellular loops than intracellular loops. c) The binding region for the G-protein involves two extracellular loops. d) The N-terminal chain is extracellular and the C-terminal chain is intracellular.

D Why? Option a is wrong since there are 7 transmembrane hydrophobic regions. Option b) is wrong since there are the same number of intracellular and extracellular loops. Option c) is wrong since the binding region of the G-protein involves one of the intracellular loops and the C-terminal chain

Which of the following statements is NOT TRUE regarding the binding site of a receptor? a) The binding site is normally a hollow or cleft in the surface of a receptor. b) The binding site is normally hydrophobic in nature. c) Chemical messengers fit into binding sites and bind to functional groups within the binding site. d) The binding site contains amino acids which are important to the binding process and a catalytic mechanism.

D Why? Receptors do not catalyze reactions and so the binding site does not contain amino acids involved in a catalytic process.

Which of the following statements is NOT TRUE about receptors? a) most receptors are proteins situated in the cell membrane b) receptors contain a hollow or cleft on their surface which is known as a binding site c) receptors bind chemical messengers such as neurotransmitters or hormones d) receptors catalyze reactions on chemical messengers

D Why? The binding site of receptors is analogous to the active site of enzymes. The ligand for the binding site acts as a chemical messenger. It binds and causes an induced fit that results in 'knock on effects' which lead to a message being received in the cell. Most receptors are present in the cell membrane although some are intracellular.

9. A physician friend of yours is telling you about a patient with a head injury who suddenly stopped breathing. Your friend explains that the bony rim was pressing against the breathing center. You guess that the "bony rim" (whatever that is) must have been exerting pressure in the region of the A) basal ganglia and hippocampus. B) cerebellum and cerebrum. C) thalamus and hypothalamus. D) medulla oblongata and pons.

D) medulla oblongata and pons. - Medulla oblongata and pons control breathing - Forebrain - cerebrum, thalamus, hypothalamus - Midbrain - midbrain - Hindbrain - pons, medulla oblongata, cerebellum

5. Which of the following is not involved in the signal transduction pathway for the detection of odorants? A. A G protein B. Adenylyl cyclase C. A specific odorant molecule receptor D. A gated ion channel in the endoplasmic reticulum E. A cAMP gated ion channel

D. A gated ion channel in the endoplasmic reticulum

Which of the following cellular responses to signal transduction would include activation of transcription? A. rapid enzyme activation. B. rapid enzyme inhibition. C. opening of ion channels in the plasma membrane. D. increased expression of certain genes. E. changes in the calcium concentration in the cytosol.

D. increased expression of certain genes.

Which of the following statements regarding vertebrate neurotransmitters is false? a. Most synapses (numerically) in the CNS use amino acid neurotransmitters. b. In the CNS, many receptors for biogenic amines mediate fast ionic responses. c. Biogenic amines are found in relatively few neurons in the CNS. d. A neuroactive peptide may be co-released with one or more small-molecule neurotransmitters and may function as a cotransmitter. e. Peptides are present in substantial numbers of CNS neurons.

In the CNS, many receptors for biogenic amines mediate fast ionic responses.

What is the mechanistic explanation for sensitization? a. Decrease in chloride flux b. Increase in sodium flux c. Increase in potassium flux d. Decrease in potassium flux e. Increase in calcium flux

Increase in calcium flux

The sound of the alarm clock in the morning triggers which type of sensory receptor in the sleeper?

Mechanoreceptor

Which of the following statements best describes long-term potentiation? a. More sodium entering the postsynaptic membrane per presynaptic action potential b. More neurotransmitter released per action potential c. More action potentials sent per second d. Action potentials display a larger depolarization e. More calcium released per action potential

More sodium entering the postsynaptic membrane per presynaptic action potential

Stretch-gated Na+ ion channel receptors are of most use in which type of sensory receptor cell?

Muscle sensor

The main ion responsible for the excitatory postsynaptic potential (EPSP) is a. Na+. b. K+. c. Cl-. d. Ca2+. e. Cl- or K+.

Na+

Ligand-gated channels on the postsynaptic membrane open and K+ and Na+ both move through these channels in opposite directions. Why then do we measure depolarization on the postsynaptic membrane? a. Na+ has a much stronger driving force into the cell. b. K+ has a much stronger driving force into the cell. c. Na+ has a much stronger driving force out of the cell. d. K+ has a much stronger driving force out of the cell. e. K+ moves out of the cell, then back into the cell.

Na+ has a much stronger driving force into the cell.

Which type of sensory receptor is not an ionotropic receptor?

Olfactory receptor

Which is the correct order of the series of reactions set in motion when a rhodopsin molecule is activated?

Photon absorption, activation of G protein, second messenger diffusion, closing of Na+ channels

Which of the following statements regarding chemical synapses is false? a. Chemical synapses can be excitatory or inhibitory. b. Chemical synapses transmit information in only one direction. c. Chemical synapses have high plasticity. d. Pre- and postsynaptic currents are always similar. e. Neurotransmitters diffuse across the synapse.

Pre- and postsynaptic currents are always similar.

Which of the following is most uniquely associated with a metabotropic receptor? a. Neurotransmitter b. Second messenger c. Ligand-gated receptor d. Voltage-gated receptor e. Synaptic vesicle

Second messenger

Which of the following best represents the order of the flow of information from a muscle in a crayfish that will ultimately generate an action potential in the crayfish stretch receptor neuron?

Stretch, stretch-gated Na+ channels open, receptor potential, voltage-gated Na+ channels open, action potential

What is the difference between synaptic facilitation and behavioral sensitization? a. Synaptic facilitation is a short term response and behavioral sensitization is a long term response. b. Synaptic facilitation is related to the sensory system and behavioral sensitization is related to the motor system. c. Synaptic facilitation underlies behavioral sensitization. d. They are both fundamentally the same thing. e. Synaptic facilitation depresses the stimulation, and behavioral sensitization sensitizes it.

Synaptic facilitation underlies behavioral sensitization.

What effect would injecting a leg muscle with a drug that binds to and disables acetylcholinesterase have on that leg? a. Delayed paralysis b. Immediate tetany c. Tetany once the leg muscle was contracted d. Paralysis once the leg muscle was contracted e. There would be no effect.

Tetany once the leg muscle was contracted

Which of the following statements regarding saltwater fish is true?

The concentration of solutes in the internal fluids of saltwater fish is much lower than that in the surrounding water.

What is a major difference between filtrate in the nephron and urine leaving the bladder?

The filtrate contains amino acids and vitamins, but urine does not.

Which of the following statements about the neuromuscular junction acetylcholine (Ach) receptor is false? a. The probability an ACh channel will open depends on ACh concentration. b. The synaptic current is the sum of the net ionic currents through all activated ACh receptors. c. The opening of the ACh receptor is all-or-none. d. The probability that an ACh channel will open depends on membrane voltage. e. The current through a single receptor can be measured with a patch clamp technique.

The probability that an ACh channel will open depends on membrane voltage.

What characteristic is found in the visual systems of all types of organisms?

The visual protein rhodopsin

Which of the following statements regarding metabotropic receptors is false? a. They can be a G protein-coupled receptor. b. They can directly open or close ion channels. c. They can activate a G protein. d. They usually use a second messenger. e. They mediate membrane voltage changes via slow postsynaptic potentials.

They can directly open or close ion channels.

Which statement about sensory receptor cells is false?

They respond to any type of stimulus.

The olfactory apparatus of mammals includes highly folded microvilli and cilia within the nasal region. What is the likely purpose of this greatly increased surface area?

To increase the mammal's sensitivity to olfactory stimuli

A male insect's body contains neurons that detect tiny concentrations of pheromones, or attractant molecules secreted by the female insect. The neurons change these chemical signals into electrical signals. Would these neurons be considered sensory receptor neurons?

Yes, because they receive and transform sensory information.

The molecular mechanism by which light is absorbed into visual systems is

a shift between isomers of the retinal molecule.

The middle ear assists the processing of auditory information by converting _______ pressure waves into _______.

air; fluid pressure waves

Which of the following nitrogenous wastes requires the greatest amount of water to excrete?

ammonia

A major difference between rods and cones in the human eye is that cones

are responsible for color vision.

Which arrow in this schematic view of the nephron shows reabsorption?

arrow c

The structure in the ear that is most directly responsible for the ability to discriminate different pitches of sound is the

basilar membrane.

Which of the following animals are endotherms?

birds and mammals

Secretion is the movement of substances such as drugs or toxic molecules from the ______ into the ____.

blood:filtrate

Color vision in the human eye is possible because

cone cells have three types of rhodopsin, which respond to different wavelengths.

It is a cool winter evening, and you are feeling a little chilled. To warm yourself up, you sip some hot tea. As you swallow, you can feel the tea warm your mouth and throat. The drink is warming you up by the process of

convection.

Epinephrine is a. excitatory. b. inhibitory. c. simultaneously excitatory and inhibitory. d. neither excitatory nor inhibitory. e. either excitatory or inhibitory.

either excitatory or inhibitory.

Animals that maintain internal body temperature using heat generated by their own metabolism are called

endotherms.

Which of the following helps cool animal bodies?

evaporation

Which of the following options correctly lists the structures in the kidney in the order in which fluid flow through them?

glomerulus, Bowman's capsule, proximal tubule, loop of Henle, distal tubule.

Which of the following physiological responses occurs in the human body when it becomes overheated?

increased blood flow to the skin

When an individual rod or cone cell is stimulated with light,

its membrane potential becomes more negative.

All sensory information enters the brain in the form of electrical impulses, or action potentials. The brain determines the source of the sensory information based on the

location at which the signals arrive.

Thermoregulation, osmoregulation, and excretion are _____.

mechanisms that moderate change in the body

An aquatic animal that has the same solute concentration as its environment is a(n) _____.

osmoconformer

Which of the following is a function of the human kidney?

processing of blood to form filtrate material, from which metabolic wastes are discarded

Where along the nephron is glucose reabsorbed from the filtrate back into the blood?

proximal tubule

Plants have specific temperatures (or temperature ranges) that allow for maximum growth. A process by which heat from ________ is transferred from the sun to leaves helps give plants these ideal temperatures.

radiation

When a dog picks a sunny and sheltered spot in the yard for a nap on a cool fall day, what mechanism of heating is the dog taking advantage of?

radiation

Compared to an ionotropic receptor cell, a metabotropic receptor cell is more likely to have a

receptor protein that is a G protein or activates one.

The limiting factor in the synthesis of acetylcholine is the a. speed at which acetyl groups are formed. b. speed at which vesicles are formed. c. frequency of the action potentials produced. d. speed at which choline is recycled. e. speed at which vesicles release choline.

speed at which choline is recycled.

Transduction of information in sensory receptor cells results in a change from

stimulus energy to electrical energy.

The protein responsible for triggering the actual release of neurotransmitter at the synapse is a. synapsin. b. synaptotagmin. c. SNARE. d. dynamin. e. sytaxin.

synaptotagmin.

Which part of the nephron is most directly involved in the filtration of blood?

the Bowman's capsule

Thermoregulation, an important part of homeostasis, is defined as

the maintenance of internal body temperature within an optimal range despite change in external temperature

What is the functional unit of the kidney?

the nephron

The induction of long-term potentiation occurs in a. the presynaptic neuron. b. the synapse. c. the postsynaptic neuron. d. the motor neuron. e. both the pre- and postsynaptic neurons.

the postsynaptic neuron.

The primary nitrogen-containing compound excreted by kidneys of mammals is _____.

urea

The most effective molecule for nitrogenous waste disposal in desert animals would be _____.

uric acid because it does not require water for excretion

Birds, like other animals, must eliminate ammonia or urea. They do so by converting it to

uric acid.

What is the function of antidiuretic hormone?

- to increase water reabsorption

What is the function of urea reabsorption in the collecting ducts of the kidney?

-It increases the osmotic concentration of the interstitial fluid in the renal medulla so that more water can be extracted from the urine.

What happens to glucose in the filtrate as it passes through the proximal tubule?

-it is reabsorbed