Bio 2 Exam 3 Practice (1)

You put a solution of sucrose into a bag of dialysis tubing, which is permeable to water but not to sucrose. You then put this bag into a beaker of water. An hour later, you observe that the bag has swelled due to...
A.the high osmolarity of the surrounding water
B. passive transport of sucrose molecules
C. the osmotic pressure of the sucrose solution
D. active transport of water molecules

C. the osmotic pressure of the sucrose solution

Which of the following is a function of excretory systems?
A. They help regulate osmotic potential and the volume of extracellular fluids
B. They excrete molecules that are present in excess
C. They conserve molecules that are valuable or in short supply
D. All of the above

D. All of the above

The reabsorption of glucose, amino acids, and many other molecules needed by the body is driven by \______________.
A. active transport carriers
B. diffusion
C. facilitated diffusion
D. homeostasis

A. active transport carriers

Select the incorrectly matched osmoregulatory organ and the organism that uses it.
A. antennal glands—annelids
B. protonephridia—flatworms
C. malpighians tubules—insects
D. kidney—fish

A. antennal glands-annelids

Which of the following molecules is most toxic to cells?
A. Sodium chloride
B. Ammonia
C. Urea
D. Uric acid

B. Ammonia

Differentiate between an osmoconformer and an osmoregulator.

Osmoconformer: An animal that maintains the osmotic concentration of its body fluids at about the same level as that of the medium in which it is living (ex.: marine animals).
Osmoregulators: An animal that maintains a relatively constant blood osmolarity despite the different concentration in the surrounding environment (they control their temperature internally).

What are the 3 nitrogenous wastes?

Ammonia, urea, and uric acid.

Which animal excretes ammonia?
Which animal excretes urea?
Which animal excretes uric acid?

-Ammonia: Bony fish and aquatic invertebrates
-Urea: Mammals, amphibians, and cartilaginous fish
-Uric acid: Reptiles, birds, and insects

Which nitrogenous waste product is most costly to produce?

Uric acid, but it saves water.

\________________________ \= Amt. filtered - Amt. reabsorbed + Amt. secreted

Amt. excreted

What type of exchange occurs with a seabird drinking saltwater?

Countercurrent exchange

Select the incorrectly matched vertebrate and its urine concentration relative to its blood.
A. amphibians—isotonic
B. marine reptiles—isotonic
C. desert mammals—strongly hypertonic
D. marine mammals—strongly hypertonic
E. terrestrial birds—weakly hypertonic

A. amphibians- isotonic.
*They actually have a hypotonic urine concentration.

From a health standpoint, which of the following is probably the healthiest to drink?
A. Bottled water
B. Tap water
C. Sports drinks
D. Energy drinks
E. Vitamin water

B. Tap water

Terrestrial organisms must conserve water. The least amount of water is lost with the excretion of which nitrogenous waste product?
A. Carbon dioxide
B. Uric acid
C. Ammonia
D. Urea

B. Uric acid

Marine invertebrates in which the salinity of body fluids changes with the osmotic potential of their environments are known as...
A. osmoconformers
B. osmoregulators
C. hypotonic
D. hypertonic

A. osmoconformers

Which of the following best describes freshwater fish?
A. hypotonic osmoregulators
B. hypotonic osmoconformers
C. hypertonic osmoregulators
D. hypertonic osmoconformers
E. isotonic osmoconformers

C. hypertonic osmoregulators

Organisms living in a freshwater environment normally...
A. excrete copious dilute urine and retain salts
B. excrete a small volume of dilute urine and retain salts
C. excrete copious concentrated urine
D. conserve both water and salts

A. excrete copious dilute urine and retain salts

Saltwater fish achieve water balance by...
A. Excreting water
B. Retaining salts
C. Drinking salt water and excreting salts
D. Excreting salts with a nasal salt gland

C. Drinking salt water and excreting salts

Marine invertebrates in which the salinity of body fluids changes with the osmotic potential of their environments are known as...
A. osmoconformers
B. osmoregulators
C. hypotonic
D. hypertonic

A. osmoconformers

Marine invertebrates in which the salinity of body fluids changes with the osmotic potential of their environments are known as...

Which of the following operates by passing fluids into a tube, and then secreting or reabsorbing specific substances?
A. Flame cells of flatworms
B. Metanephridia of annelid worms
C. Malpighian tubules of insects
D. Vertebrate nephrons
E. All of the above

E. All of the above

Be sure that you can label the following diagram of the urinary system.

What is the order of the urinary system?

nephron \> Bowman's capsule \> glomerulus \> proximal convoluted tubule \> descending limb \> loop of Henle \> ascending limb \> distal convoluted tubule \> collecting duct \> ureter

What are the three functions of the kidney?

Filtration (out of glomerulus), reabsorption (tubules into capillaries), and secretion (into tubules from capillaries).

Flip the card.

Proximal convoluted tubule:
Active transport of glucose and other valuable solutes out of tubule
Active transport of Na+
Cl- follows
Water follows osmolarity gradient
Descending loop:
Permeable to water
Impermeable to NaCl
Water moves out of tubule
Longer loop of Henle \= more concentrated filtrate due to more water being removed
Ascending loop:
Impermeable to water
Active transport of Na+ out of tubule
Cl- follows
Distal convoluted tubule
Filtrate arrives hypotonic
Collecting duct
Final reabsorption of water
Help urine increase concentration

Refer to the diagram, do you understand what it's showing?

True or false: Kidney function is regulated by ADH.

True.

The mammalian kidney contains structures that can perform various functions. These functions include:
I-excretion.
II-reabsorption.
III-secretion.
IV-filtration.

All of the above.

Which structure is found in the renal medulla?
A. Bowman's capsule
B. Convoluted tubule
C. Glomerulus
D. Loop of Henle
E. Both A and D

D. Loop of Henle

Animals that have very long juxtamedullary nephrons likely live in \______ environments
A. marine
B. freshwater
C. arid
D. tropical forest

C. arid

The kidneys are important homeostatic organs, contributing to the stability of all of the following except:
A. blood volume.
B. immunity.
C. blood pressure.
D. electrolytic concentration.
E. pH.

B. immunity

A person with diabetes insipidus fails to respond to ADH. Which of the following is a symptom of this condition?
A. Glucose in urine
B. Copious dilute urine
C. Small volume of concentrated urine
D. Failure to urinate

B. Copious dilute urine

Which process drives the process of filtration from the capillaries into the glomerulus?
A. Active transport
B. Arterial blood pressure
C. Venous blood pressure
D. Osmotic pressure
E. Secretion

B. Arterial blood pressure

An important function of the proximal convoluted tubule is \_____.
A. Filtration of NaCl
B. Reabsorption of water
C. Countercurrent heat exchange
D. Production of urea
E. Secretion of water

B. Reabsorption of water

Valuable molecules like glucose, amino acids, and vitamins are mostly reabsorbed into the blood at which location in the nephron?
A. Bowman's capsule
B. Collecting duct
C. Glomerulus
D. Loop of Henle
E. Proximal convoluted tubule

E. Proximal convoluted tubule

An osmotic gradient in the kidney medulla is established by...
A. Countercurrent exchange between ascending and descending loops of Henle
B. Countercurrent exchange between the loop of Henle and collecting ducts
C. Filtration of large proteins in the glomerulus
D. Movement of water out of the collecting duct
E. Movement of NaCl into the proximal tubule

A. Countercurrent exchange between ascending and descending loops of Henle

In response to dehydration, ADH...
A. Signals aquaporins to be added to cell membrane
B. Signals aquaporins to be added to vesicles
C. Stimulates production of angiotensin II
D. Stimulates thirst response
E. Activates the juxtaglomerular apparatus

A & D

Innate immunity...
A. is activated immediately upon infection.
B. depends on a newly infected animal's previous exposure to the same pathogen.
C. is based on recognition of antigens that are specific to different pathogens.
D. is found only in mammals.

A. is activated immediately upon infection.
*Fast compared to adaptive immunity.

Which of the following is unique to the adaptive immune defense system?
A. cells that ingest invading microbes
B. antibody synthesis
C. inflammation
D. fever

B. antibody synthesis

The large, irregularly shaped cells that kill bacteria by digesting them are called...
A. erythrocytes.
B. macrophages.
C. bacteriophages.
D. antibodies.

B. macrophages

The molecule that provokes a specific immune response is a(n)...
A. antigen.
B. lymphocyte.
C. antibody.
D. lysozyme.

A. antigen

When an individual is first exposed to the smallpox virus, several days pass before significant numbers of specific antibody molecules and T cells are produced. However, a second exposure to the virus causes a large and rapid production of antibodies and T cells. This response is an example of...
A. antigenic determinants.
B. phagocytosis.
C. interferon production.
D. immunological memory.

D. immunological memory.

What is the first line of defense?

The skin.

What is the role of helper T cells?

Recognizes foreign peptides on antigen-presenting cells, including the release of cytokines that activate B cells or macrophages.

What is the role of cytotoxic T cells?

Specifically recognizes and kills "altered self".

What is the role of B cells?

Binds specific soluble antigens with its membrane-bound antibody; serves as an antigen-presenting cell. On activation, it can differentiate into plasma and memory B cells.

What is the role of a Natural Killer cell?

Rapidly recognizes/finds and kills virally infected and tumor cells.

What is a monocyte?

It's the precursor of a macrophage.

What is the role of a macrophage?

A phagocytic tissue cell which is part of the body's first line of defense. It can serve as an antigen-presenting cell to T cells. It comes and eats the crumbs, left by the natural killer cells.

What are neutrophils attracted to?

Tissues during inflammation.

What is the role of a mast cell?

Releases mediators such as histamine which prevent inflammation.

What is the role of a dendritic cell?

Antigen-presenting cell to naive T cells, also helps in the activation of these cells.

What makes up adaptive immunity (which is a slow response)?

B cells with antibodies and T cells with CD4+/CD8+ T cells.

What is the role of an interferon?

It signals the uninfected cells to destroy RNA and reduce protein synthesis.

Which of the following is used by infected cells as part of the signaling of the inflammatory response?
A. Natural killer cells
B. Phagocytotic neutrophils
C. Histamine
D. Antihistamine
E. Red blood cells

C. Histamine

Which of the following statements best describes the role of mast cells in the inflammatory response?
A. They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream.
B. They secrete substances that degrade bacterial cell walls and engulf and digest the invaders.
C. They release chemicals that constrict blood vessels at some distance from the wound site.
D. They release cytokines to stimulate the release of additional neutrophils and macrophages.

A. They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream.

Which statement is false regarding vaccines?
A. They often contain dead pathogens with intact antigens.
B. They use weaker versions of the pathogen with intact antigens.
C. They often contain heat-killed pathogens that kills off the antigens.
D. Some vaccines simply contain subunits of the pathogen.

C. They often contain heat-killed pathogens that kills off the antigens.

Vaccines are an example of:
A. Passive immunity that requires memory cells
B. Active immunity that requires memory cells
C. Passive immunity that does not require memory cells
D. Active immunity that does not require memory cells

B. Active immunity that requires memory cells

Which of the following statements is false regarding antigens?
A. They are often large proteins.
B. They are foreign substances on the pathogen that provoke an immune response.
C. The more phylogenetically different they are from the host, the greater immune response.
D. Antigens can have many parts, called epitopes.
E. All epitopes on the same antigen result in identical immune responses.

E. All epitopes on the same antigen result in identical immune responses.

What is specificity?

Immune cells recognizing and reacting with individual molecules (antigens) via direct molecular interactions.

What is tolerance?

Immune cells are not able to react with self antigen. Self-reactive cells are destroyed during development of the immune response.

What is memory?

The immune response to a specific antigen is faster and stronger upon subsequent exposure because the initial antigen exposure included growth and division of antigen-reactive cells, resulting in multiple copies of antigen-reactive cells.

What is cell lysis?

Where a cell essentially explodes.

Refer to the image displaying an antigen, antibody, and an epitope.

Immunologists can breed mice that lack \_______ in order to compare the immune response of normal mice to those that have no T cells.
A. a thymus
B. a spleen
C. bone marrow
D. kidneys
E. a liver

A. a thymus

The lymphatic fluid...
A. is a filtrate of the blood, as is urine.
B. is completely separate from the circulatory system for blood.
C. carries both red and white blood cells.
D. functions in adaptive immunity but not in innate immunity.
E. carries a toxic gas that kills cancerous cells.

A. is a filtrate of the blood, as is urine.

An epitope is...
A. part of the interferons that penetrate foreign cells.
B. a protein protruding from the surface of B cells.
C. two structurally similar antibodies dissolved in the blood plasma.
D. that part of an antigen that actually binds to an antigen receptor.
E. a mirror image of an antigen.

D. that part of an antigen that actually binds to an antigen receptor.

The function of antibodies is to...
A. inject toxins into living pathogens.
B. secrete cytokines that attract macrophages to infection sites.
C. release perforins to disrupt infected cells.
D. mark pathogenic cells for destruction.

D. mark pathogenic cells for destruction.

The MHC is important in a T cell's ability to...
A. distinguish self from non-self.
B. recognize specific parasitic pathogens.
C. identify specific bacterial pathogens.
D. identify specific viruses.
E. recognize differences among types of cancer.

A. distinguish self from non-self.

When a T cell is activated by an antigen, it will most likely...
A. secrete antibodies
B. proliferate
C. die
D. become a hybridoma
E. become a plasma cell

B. proliferate

What type of cell releases histamines?

B-cells.

Which of the following components of the immune system destroys bacteria by punching holes in the wall of the bacteria resulting in cell lysis?
A. Complement protein
B. Macrophages
C. Plasma cells
D. Major histocompatibility complex (MHC) proteins

A. Complement protein

\_________ are molecules released by activated helper T cells...
A. Antigens
B. Immunoglobulins
C. Cytokines
D. Antibodies

C. Cytokines

What's an antigen presenting cell?

A cell that displays antigen complexed with MHCs on their surfaces.

Is this order true?
1. Helper T cells signal to B cells
2. B cells become plasma cells
3. Plasma cells release antibodies

Yes.

What are two main classes of immunoglobulins?
Refer to the image.

IgM and IgG.
IgE is also an important one, it is produced in high abundance due to inflammation/allergies.

How can untreated Crohn's disease affect other areas of the body such as the eyes, skin, and joints?
A. Extensive and chronic inflammation caused by the T-cell response in the guts means that cytokines and other inflammatory proteins can be carried to other parts of the body through the bloodstream
B. Extensive damage to the mucosal lining of the intestines can lead to malnutrition and deplete other areas of the body of needed nutrients
C. Activated T-cells spread throughout the body and attack other mucosal linings
D. All of the above
E. Both A & B

E. Both A & B

What is not a key trait of the adaptive immunity response?

Rapid response.

Which of the following is a difference between B cells and T cells?
A. One has a major role in antibody production, while the other has a major role in cytotoxicity.
B. One uses a receptor called BCR, while the other recognizes a receptor called TCR.
C. B cells are activated by free-floating antigens in the blood or lymph. T cells are activated by membrane-bound antigens.
D. T cells are produced in the thymus and B cells are produced in the bone marrow.

A. One has a major role in antibody production, while the other has a major role in cytotoxicity.

Which of the following do Helper T-cells not directly carry out?
A. Phagocytosis
B. Activate B-cells
C. Activate cytotoxic T-cells
D. Produce cytokines

A. Phagocytosis

The operation of the sodium-potassium "pump" moves...
A. sodium and potassium ions into the cell.
B. sodium and potassium ions out of the cell.
C. sodium ions into the cell and potassium ions out of the cell.
D. sodium ions out of the cell and potassium ions into the cell.

D. sodium ions out of the cell and potassium ions into the cell.

The multiple cytoplasmic extensions of a neuron are called...

Dendrites.

Most of the neurons in the human brain are...
A. sensory neurons.
B. motor neurons.
C. interneurons.
D. auditory neurons.
E. peripheral neurons.

C. interneurons

What is the correct distribution of ions in a resting neuron?

-K is larger on inside of cell
-Na is smaller on inside of cell
-Cl is smaller on inside of cell

What makes up the CNS vs. the PNS?

CNS- brain, spinal chord.
PNS- cranial/spinal nerves.
In addition, the PNS has sensory/motor neurons while the CNS has interneurons.

Refer to the image of a neuron.

Ion (leak) channels differ from gated channels in that the former...
A. use carrier proteins
B. are always open
C. only allow anions to pass through the membrane
D. require ATP

B. are always open

True or False: Ions are able to move across the cell membrane when no channels are present.

False.

What are the three causes of the membrane potential in a resting cell?

1. Sodium-potassium pump
2. Potassium ion channels
3. Negatively charged proteins on the inside of a cell

Which of the following describes the resting potential of the neuronal cell membrane?
A. The inside is 70 millivolts more positive than the outside
B. The outside is 70 millivolts more positive than the inside
C. The inside is 30 millivolts more positive than the outside
D. The outside is 30 millivolts more positive than the inside

B. The outside is 70 millivolts more positive than the inside

The resting potential of a neuron is produced primarily by...
A. voltage-gated channels in the membrane
B. chemically gated channels in the membrane permanently open
C. potassium channels in the membrane
D. the concentration difference in Na+ across the membrane
E. blockage of the sodium-potassium pump

C. potassium channels in the membrane

Neurons that transmit information from sensory cells to the central nervous system are part of the...

PNS.

The membrane of a resting neuron is much more permeable to which of the following ions than any other ion?
A. Cl-
B. Ca2+
C. Na+
D. K+
E. H+

D. K+

Two fundamental concepts about gated channels are that they...
A.are always open, but the concentration gradients of ions frequently change.
B. are always closed, but ions move closer to the channels during excitation.
C. open and close depending on stimuli, and are specific as to which ions can traverse them.
D. open and close depending on chemical messengers, and are nonspecific as to which ion can traverse them.

C. open and close depending on stimuli, and are specific as to which ions can traverse them.

The resting potential of a neuron is primarily produced by...
A. voltage-gated channels in the membrane.
B. chemically gated channels in the membrane.
C. potassium channels in the membrane that are permanently open.
D. the concentration difference in Na+ across the membrane.

C. potassium channels in the membrane that are permanently open.

Which of the following describes the mechanism of voltage-gated channel proteins?
A. If membrane voltage reaches threshold potential, ions are pumped through
B. If membrane voltage reaches threshold potential, ions can diffuse through
C. Ions are pumped through to maintain existing membrane voltage
D. When gates close, membrane voltage changes

B. If membrane voltage reaches threshold potential, ions can diffuse through

A shift in the membrane potential toward the positive direction and exceeding the threshold causes a(n)...
A. resting potential.
B. equilibrium potential.
C. action potential.
D. ion current.

C. action potential.

Nerves \_______ have the most rapid action potentials.
A. with the thinnest axon diameters
B. with the shortest length
C. with myelin sheaths
D. with the most ion channels

C. with myelin sheaths

The process in which impulses jump from node to node is called...
A. going through channels.
B. interrupted signals.
C. repolarization.
D. saltatory conduction.

D. saltatory conduction.

The junction between a neuron and another neuronal cell, muscle cell, or with a gland cell is called a(n)...

synapse.