Exam 4 review

How many molecules of O2 can a single hemoglobin molecule carry when fully saturated?

4

A person inhales a potentially pathogenic bacterium. What defenses will the bacterium encounter as it travels through the human body? digestive enzymes in the stomach (if the bacterium enters the gastrointestinal tract) phagocytes (if the bacterium enters the bloodstream) All of these choices are correct. mucus and cilia in the respiratory tract (if the bacterium enters the respiratory tract) hairs in the nasal cavity

All of these choices are correct.

Helper T cells activate other cells of the immune system, including: All of these choices are correct. macrophages. cytotoxic T cells. B cells.

All of these choices are correct.

The basic unit of the kidney, the nephron, contains: renal tubules. All of these choices are correct. the collecting duct. the glomerulus.

All of these choices are correct.

Which of the answer choices composes the immune system? organs All of these choices are correct. proteins cells

All of these choices are correct.

Which of the statements about Malpighian tubules is correct? They are a series of tubes that empty into the hindgut of insects. They actively secrete uric acid and excess electrolytes while retaining key solutes. They allow nitrogenous wastes to be excreted with minimal water loss. All of these choices are correct. They allow insects to live in dry terrestrial environments.

All of these choices are correct.

Which type of cell produces antibodies?

B cells

A lizard is sitting on a rock on a cool, cloudy morning. As the day progresses, the sun comes out, and the temperatures of the rock and the lizard increase.What changes are expected in the lizard's metabolic rate and activity level?

Both the metabolic rate and activity level will increase.

The membranous sac enclosing the glomerulus of a mammalian kidney is called:

Bowman's capsule.

One of the functions of the respiratory system is to rid the body of CO2. Where does the CO2 come from?

CO2 is a breakdown product of the carbohydrates or lipids oxidized in cellular respiration.

Which of the statements is true regarding CO2 in the mammalian bloodstream?

CO2 is mainly transported through the mammalian bloodstream in the form of bicarbonate ions or carbonic acid.

You are a doctor who examines a swollen and warm puncture wound on the hand of a patient. Which was not a response of the patient's immune system to this injury when it occurred?

Cell division was inhibited at the wound site.

Which of the following statements about open and closed circulatory systems is false?

Closed circulatory systems use muscular hearts to pump blood through blood vessels, whereas open circulatory systems lack any kind of muscular pump.

All of the statements are true except: Chemoreceptors involved in the homeostatic control of breathing are located in the brainstem and the carotid and aortic bodies. As an organism's activity level increases, the level of CO2 in the blood will increase and stimulate faster or stronger breathing. Breathing is controlled by both voluntary and involuntary mechanisms. Stronger or more frequent contraction of respiratory muscles helps to remove excess CO2 from the blood. Decreasing levels of oxygen in the blood are detected by chemoreceptors in the kidney.

Decreasing levels of oxygen in the blood are detected by chemoreceptors in the kidney.

Which of the statements is accurate? Amphibians and most reptiles have a four-chambered heart consisting of two atria and one ventricle. There is a complete separation of pulmonary and systemic circulation in amphibians and most reptiles. Amphibians only respire through their lungs. Diving reptiles can alter the pattern of blood circulation to bypass their lungs when submerged.

Diving reptiles can alter the pattern of blood circulation to bypass their lungs when submerged.

Why would the loss of helper T cells due to HIV infection result in the immunodeficiency associated with AIDS?

Helper T cells are central to the activation of other parts of the immune system.

Which of the statements is true? Human blood pressure in the pulmonary circulation is lower than blood pressure in the systemic circulation. The systemic blood pressure of a bird is lower than that of a fish. The walls of the human right ventricle are thicker than the walls of the left ventricle. The human left ventricle pumps deoxygenated blood, whereas the right ventricle pumps oxygenated blood.

Human blood pressure in the pulmonary circulation is lower than blood pressure in the systemic circulation.

What is the purpose of getting a flu shot every year?

It exposes you to antigens present on the flu virus specific to this year infectious strain so that your immune system can make antibodies to the virus.

Which of the statements about myoglobin is true?

Myoglobin is found within vertebrate muscle cells.

Innate immunity activation depends on: D. memory B cells. A. previous exposure to a foreign antigen. B. diversity of antibodies in the blood stream. C. MHC class II proteins. E. None of the other answer options is correct.

None of the other answer options is correct.

Which of the statements about the process of excretion in complex multicellular animals is true?

Selective filtration of the blood occurs as blood pressure forces materials into an extracellular space.

The body fluid of sharks has a much lower concentration of sodium chloride than that of the surrounding seawater, and sharks are able to remain in osmotic equilibrium with the external environment.How can this be the case?

Sharks store enough urea to match the total solute concentration of the surrounding seawater.

What effect does the nervous system have on the heart rate?

Stimulation by parasympathetic nerves causes the heart rate to slow down.

You are a doctor and have a patient who has been injured by a rusty nail. As a precaution, you vaccinate her against tetanus. In response to the vaccine, how does her body produce antibodies against C. tetani and prevent future illness due to tetanus?

The B cell with the appropriate antibody is stimulated to divide, producing plasma cells that make antibodies to C. tetani, and memory cells that "remember" C. tetani.

Which of the statements about veins is true? The blood pressure within the veins is much lower than the blood pressure within the arteries. Only 20% of the total blood volume resides in the venous circulation at any given time. Veins have thicker walls than arteries. Veins located in the head have one-way valves that help prevent blood from pooling due to gravity.

The blood pressure within the veins is much lower than the blood pressure within the arteries.

Which of the changes occurs during exhalation?

The diaphragm relaxes and pushes up.

What would happen to a mammalian heart if the nerves leading to it were severed?

The heart muscle would continue to contract but its contraction rate may change.

Which of the statements about insect respiration is true?

The insect respiratory system is composed of a series of branching tubes called tracheae.

Which of the statements about metabolic rate is false?

The metabolic rate per gram of tissue is greater in large endotherms than in small endotherms.

Tetanus is a bacterial infection that is commonly acquired from puncture wounds. Why do you need to be vaccinated against the flu every year, but you only need a virus booster against tetanus every 10 years?

There is a higher rate of mutation in viruses than in bacteria, so you need to change the antibodies you are producing (through vaccination) every year for the flu.

How do immune cells with sensitivity to self antigens become eliminated?

They undergo cell death.

As a person ages, his or her thymus shrinks. How does this change affect the effectiveness of vaccinations?

Vaccinations will be less effective because the rate of T cell maturation will be reduced.

The excretory organs of different organisms are extremely varied.What do all excretory organs have in common?

a filtration system that filters nitrogenous waste from the body fluids

Osmosis requires:

a semipermeable membrane separating areas of different solute concentrations.

What type of cells are targeted by a cytotoxic T cell? a virus-infected host cell All of these choices are correct. an encapsulated bacteria an opsonized pathogen

a virus-infected host cell

Which of the choices is not a specialized function of one or more regions of the digestive tract?

aerobic metabolism

You are literally running late to class. After your initial panic, you realize that you can make it on time at your regular jogging pace. You have been jogging for a few minutes and have a few minutes left before you arrive.At this point, how are your muscles providing themselves with energy?

aerobic respiration

Which of these hormones increases blood pressure by directly stimulating the distal convoluted tubule and collecting ducts to take up more water and salts?

aldosterone

List the three major forms of nitrogenous waste in order from highest amount of water required for excretion to lowest amount of water required for excretion.

ammonia, urea, uric acid

Which of the following is required to activate a helper T cell, which in turn can stimulate antibody production by B cells?

an antigen and a major histocompatibility complex protein

Most proteins consumed in the diet:

are digested into amino acids and absorbed, and may be re-polymerized into the proteins the body needs.

T cell receptors (TCRs):

are generated through genetic rearrangement similar to antibody formation in B cells.

Cells in which of the following regions of the heart produce action potentials, thus orchestrating a "regular" heartbeat?

atrioventricular node

A drop of blood entering the heart from the vena cava would pass through which of these structures before moving through the pulmonary valve?

atrioventricular valve

How do T cells contribute to the immune response?

by cell-mediated immunity

A man is scratched by his cat. A phagocyte near the scratch site recognizes and engulfs a bacterium. Shortly thereafter, more phagocytes arrive in the tissue surrounding the scratch. How are the additional phagocytes recruited to the site of the scratch?

by cytokines secreted by the initial phagocyte

Diffusion of materials between the blood and body tissues occurs at which of the blood vessels?

capillaries

Lupus is an autoimmune disorder. Which of the following would you expect to be a symptom of lupus?

cells binding to antigens on host cells and targeting their degradation

B cells undergo _____, where a specific cell will divide in response to its associated antibody recognizing an antigen.

clonal selection

Which of the factors affects the rate of diffusion of a substance?

concentration gradient

Tadpoles of the African genus of frogs Hymenochirus are predatory. They track their prey, chase it, and then capture it using a suction mechanism that draws the prey into their mouth. Although suction feeding is the most common method of prey capture among fish, the closest phylogenetic relatives of these frogs all have tadpoles that are suspension filter feeders. Suction feeding in Hymenochirus tadpoles and fish is an example of:

convergent evolution.

The outer layer of the mammalian kidney is the _____, and the inner layer is the _____.

cortex; medulla

Virus-infected cells are detected and destroyed by which cell-mediated immune response?

cytotoxic T cells

What causes antigenic variation of the malarial parasite?

differential gene expression

Innate immunity is different from adaptive immunity in that innate immunity:

does not require prior exposure to a pathogen

The _____ is the first section of the small intestine, where food enters from the stomach.

duodenum

T cells can be classified as:

either helper or cytotoxic T cells.

Brine shrimp live in salt water, but the level of salt in the water where they reside can differ dramatically from day to day or longer time scales. In very high salt concentrations, a brine shrimp _____ salt across its gills and maintains an internal salt concentration that is _____ relative to the water where it lives. In lower salt concentrations, a brine shrimp _____ salt water across its gills and maintains an internal salt concentration that is _____ relative to the water where it lives.

excretes; hypotonic; absorbs; hypertonic

When a person experiences dehydration, water can be absorbed from the bladder wall to replenish needed water back to the body.

false

How is the fetus able to extract oxygen from the mother's blood?

fetal hemoglobin has a higher affinity for oxygen than maternal hemoglobin

In muscle and liver tissue, glucose consumed in the diet, but not immediately used, is stored as:

glycogen.

It is difficult to treat tuberculosis infections because the bacterium:

has developed resistance to many antibiotics.

You are a doctor examining a patient's blood-test results. The patient's T cell count is low. You are concerned that the patient will:

have a reduced ability to kill host cells if she becomes infected.

Osmoregulators _____ internal solute concentrations compared to their external environment.

have different

Which of the choices correctly describes the path of a drop of blood leaving the human heart?

heart → arteries → arterioles → capillaries → venules → veins → heart

Which of the following correctly describes the path of a drop of blood leaving the human heart?

heart → arteries → arterioles → capillaries → venules → veins → heart

Which of these changes would increase the rate of oxygen diffusion from the air into the body cells of a flatworm? All of these choices are correct. increasing the surface area of the body and the partial pressure of oxygen inside the cells increasing the thickness of the body wall increasing the surface area of the body increasing the partial pressure of oxygen inside of the cells

increasing the surface area of the body

You realize that you are late for class and begin to run across campus, which is equivalent to 15 minutes of very hard exercise.After your muscles use their stores of phosphocreatine, they will next provide themselves with energy using:

lactic acid fermentation.

In the digestive system, most of the water and inorganic ions are absorbed by the:

large intestine.

Which of the choices describes the correct path of air through the human respiratory system?

larynx, trachea, bronchi, bronchioles, alveoli

Which part of the nephron acts as a countercurrent multiplier

loop of Henle

The large number of antibodies that can be produced in a single individual is a result of:

making a unique antibody from all other B cells by genomic rearrangement.

Chemical elements other than carbon, hydrogen, oxygen, and nitrogen that are required in the diet and must be obtained from the food an animal eats are otherwise known as:

minerals

Which of the choices is an example of bulk flow during gas exchange in vertebrates? all of these choices are correct. movement of carbon dioxide from body cells into the bloodstream movement of water past a respiratory surface movement of hemolymph throughout the body movement of oxygen from the lungs into the bloodstream

movement of water past a respiratory surface

Unicellular and simple multicellular organisms isolate and eliminate waste materials by:

moving the wastes into a contractile vacuole and eliminating them through exocytosis.

A small child enters a clinic for the third time in one month with another bad skin infection filled with pus (tissue fluid combined with large numbers of bacteria growing in the fluid). Decreased numbers, or loss of function, in which of the cell types could account for these symptoms?

neutrophils

Immunodeficiency is a general term that refers to the loss of:

one or more components of the immune system.

The pulmonary veins carry:

oxygenated blood from lungs to left atrium

The key hormone of childbirth is _____, which is released from the posterior pituitary gland. It stimulates uterine contractions which, in turn, stimulate more of the hormone to be released.

oxytocin

Nitrogenous wastes are produced through the breakdown of:

proteins

Which of the macromolecules are broken down by pepsin?

proteins

The complement system refers to:

proteins circulating in the blood that are activated by antibodies or molecules on pathogens.

What is the function of surfactant in the mammalian respiratory system?

reduction of surface tension in the fluid covering the alveoli

In which of the heart chambers would deoxygenated blood be found?

right atrium and right ventricle

Blood entering the heart from the mammalian body passes through the heart chambers and lungs in which order:

right atrium, right ventricle, lungs, left atrium, left ventricle.

The internal body fluids of an osmoconformer are described as having:

roughly the same total solute concentration as the external environment.

T cell maturation in the thymus requires:

selection of T cells that do not bind tightly to self antigens.

the most nutrient absorption takes place in the?

small intestine

Which of the structures are not associated with ion regulation in animals?

tear ducts

Osmoregulation is defined as:

the control of osmotic pressure through regulation of water and solute levels.

Osmosis describes:

the movement of water from an area of lower solute concentration to an area of higher solute concentration across a selectively permeable membrane.

Peristalsis is:

the waves of muscular contractions that move food through the digestive system.

Essential amino acids must be supplied in the diet because:

they are necessary for protein biosynthesis, but we do not have the biochemical pathways to synthesize those amino acids.

In humans, T cells mature in the:

thymus

Why do cells in the airways of the lungs produce mucus?

to trap pathogens and guard against infection

Ammonia is the most toxic of the three major forms of nitrogenous waste.

true

Osmotic pressure is a function of the difference in the concentration of solutes and water on the two sides of a selectively permeable membrane.

true

Plasmodium falciparum is the most virulent of several single-cell eukaryotes known to cause malaria in humans; it is transmitted by mosquitoes.

true

Which of the structures greatly increase the surface area for nutrient absorption in the small intestines?

villi and microvilli

Your phagocytes have transmembrane proteins called toll-like receptors (TLR) on their surface, but your mast cells do not because:

your phagocytes express some genes that are not expressed in your mast cells (and vice versa).