bsc116 exam 3

Select the correct statement about capillary beds. Capillary beds are the site of nutrient and oxygen delivery to tissues. Capillary beds join arteries and veins. Capillary beds have a total cross-sectional area much smaller than the total cross-sectional area of major arteries.

Capillary beds are the site of nutrient and oxygen delivery to tissues.

Choose the correct statement from the list below. Bile salts from the gall bladder are essential to the digestion of carbohydrates. Carbohydrates are fully digested after passage through the stomach. Carbohydrate absorption occurs primarily in the large intestine. Carbohydrate digestion begins in the mouth with salivary amylase.

Carbohydrate digestion begins in the mouth with salivary amylase.

Because antigen receptor genes are randomly rearranged, some immature lymphocytes produce receptors specific for epitopes on the organism's own molecules. Why doesn't the immune system attack these molecules on the body's cells and tissues? B and T cells with receptors specific for the body's own molecules are destroyed by apoptosis. Only a very few lymphocytes produce receptors that attack the body's own molecules, so it's not a problem. The body's cells are immune to such attack.

B and T cells with receptors specific for the body's own molecules are destroyed by apoptosis.

Why does the velocity of blood slow greatly as blood flows from arterioles into capillaries? Because capillary beds are the site of nutrient and oxygen delivery to tissues. Because the narrow capillaries offer great resistance to blood flow. Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.

Because capillary beds have a total cross-sectional area much greater than the total cross-sectional area of the arterioles.

_____ is secreted by the _____ and acts to emulsify _____ in the _____. Amylase ... salivary glands ... starch ... stomach Bile ... liver ... fats ... small intestine Nucleases ... pancreas ... nucleic acids ... stomach Lipase ... small intestine ... fats ... small intestine Trypsin ... pancreas ... fats ... small intestine

Bile ... liver ... fats ... small intestine

Each person makes more than 1 million different B cell antigen receptors and more than 10 million different T cell antigen receptors. How is such diversity in antigen receptors generated? A large percentage of the vertebrate genome is devoted to genes for individual antigen-binding sites. By combining variable elements, the immune system assembles many different receptors from a much smaller collection of parts. Genes for individual antigen-binding sites have a very high rate of mutation, generating great diversity.

By combining variable elements, the immune system assembles many different receptors from a much smaller collection of parts.

How are cytotoxic T lymphocytes (CTLs) produced? CD8+ T cells divide and differentiate into cytotoxic T lymphocytes. B cells divide and differentiate into cytotoxic T lymphocytes. Helper T cells divide and differentiate into cytotoxic T lymphocytes. Plasma cells secrete cytotoxic T lymphocytes.

CD8+ T cells divide and differentiate into cytotoxic T lymphocytes.

Which three statements are true of blood flowing through a capillary at the location marked by the green circle? 1. Oxygen diffuses from the water into the blood. 2. Dissolved oxygen in the blood is lowest at this point. 3. The water surrounding the blood has a low concentration of oxygen. 4. No oxygen diffusion occurs at this point. 5. Dissolved oxygen in the blood is highest at this point. 6. The water surrounding the blood has a high concentration of oxygen.

1. Oxygen diffuses from the water into the blood. 2. Dissolved oxygen in the blood is lowest at this point. 3. The water surrounding the blood has a low concentration of oxygen.

A patient with a heart rate of 70 beats per minute and a stroke volume of 70 mL/beat will have a cardiac output of ________. 2,800 mL/minute 1,000 mL/minute 4,900 mL/minute 1,400 mL/minute

4,900 mL/minute

Select the correct statement about the immune system. Adaptive immunity is characteristic of invertebrates and vertebrates. Antibodies are secreted by T cells. All antigen receptors produced by a single B cell or T cell are identical and bind to the same epitope.

All antigen receptors produced by a single B cell or T cell are identical and bind to the same epitope.

When used appropriately, antibiotic treatment can effectively reduce bacteria populations and help fight infections. However, antibiotic treatments can have unintended effects. What is one concern when using antibiotics? Antibiotics may also kill the beneficial bacteria of the microbiome, thereby disrupting digestive health. Antibiotics also damage animal cells, so they can be more harmful than a bacterial infection. Each antibiotic is only effective against one type of bacteria, so effects on infection are limited. Antibiotics cause viruses to become more effective at infecting cells.

Antibiotics may also kill the beneficial bacteria of the microbiome, thereby disrupting digestive health.

Which of the following statements about the clonal-selection theory of immune system function is false? Antigens are recognized by receptor proteins inside the lymphocyte. An activated lymphocyte makes many copies of itself in response to an infection. Cloned cells persist after the pathogen is eliminated. Each lymphocyte recognizes one antigen.

Antigens are recognized by receptor proteins inside the lymphocyte.

What is the final step in the cell-mediated response to a viral infection? Cytotoxic T lymphocytes punch holes in the membranes of infected host cells. Macrophages digest viral particles. Antibodies coat viral particles. CD8+ T cells are activated.

Cytotoxic T lymphocytes punch holes in the membranes of infected host cells.

Choose the correct statement from the list below. Fat digestion begins in the stomach with the activation of trypsinogen to trypsin. Fats are fully digested after passage through the mouth and stomach. Bile salts from the pancreas are essential to the digestion of fats Free fatty acid absorption occurs in the small intestine.

Free fatty acid absorption occurs in the small intestine.

Consider this diagram of blood circulation in a fish. Which of the following describes the path taken by oxygen-rich blood? From the gills to the body tissues From the heart to the gills From the gills to the heart From the lungs to the body tissues From the body tissues to the heart

From the gills to the body tissues

How has the avian lung adapted to the metabolic demands of flight? There is more dead space within the avian lung so that oxygen can be stored for future use. Airflow through the avian lung is bidirectional like in mammals. Gas exchange occurs during both inhalation and exhalation. Countercurrent circulation is present in the avian lung.

Gas exchange occurs during both inhalation and exhalation.

A man who has been exposed to the flu virus is tested by his physician. The physician notes that the virus is present but no measurable level of antibodies corresponding to the virus are detected in his body. What might this mean? He was probably exposed a few days ago and clonal selection has yet to produce plasma cells. He was probably exposed more than several months ago, antibody production has ceased, and antibodies are no longer detectable. He was probably exposed sometime within the past two weeks, but we don't have enough information to say more.

He was probably exposed a few days ago and clonal selection has yet to produce plasma cells.

How do cells involved in the humoral response respond to antigen presentation on the surface of a B cell? The B cell recognizes the receptor-antigen complex and divides to produce plasma and memory cells. Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies. Helper T cells divide and produce plasma and memory cells. Helper T cells secrete antibodies against the viral antigen.

Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies.

sort these into humoral response, cell-mediated response, or both cytotoxic T cells antigen-presenting cells B cells plasma cells memory cells helper T cells and cytokines antibodies

Humoral response: B cells Antibodies Plasma cells Cell-Mediated Response:- Cytotoxic T cells Both: Helper T cells and cytokines Memory cells Antigen-presenting cells

Many people have a tendency to gorge on rich, fatty foods. How could such a preference have evolved? In ancestral hunter-gatherer communities, individuals with a tendency to gorge on such foods when available would have had a selective advantage. Most people find fatty foods tasty and satisfying. Fatty foods are very rich in calories and consuming them is an efficient way to gain weight.

In ancestral hunter-gatherer communities, individuals with a tendency to gorge on such foods when available would have had a selective advantage.

How are gases transported in insect bodies? In closed circulatory systems In tracheal systems In open circulatory systems

In tracheal systems

What is the function of a circulatory system? It exchanges oxygen and carbon dioxide with the outside air. It acts as a reservoir for the storage of blood. It brings a transport liquid into close contact with all cells in the body. It is the site of blood cell production.

It brings a transport liquid into close contact with all cells in the body.

What is the function of the left ventricle? It receives oxygenated blood from the lungs. It pumps deoxygenated blood to the lungs via the pulmonary circulation. It pumps oxygenated blood around the body via the systemic circulation. It receives deoxygenated blood from the lungs.

It pumps oxygenated blood around the body via the systemic circulation.

How do cells involved in the innate immune response detect the presence of pathogens? Leukocytes recognize the entire pathogen. Antibodies bind to the pathogens. Leukocytes recognize unique molecules on pathogens. Leukocytes recognize the secretions from a pathogen.

Leukocytes recognize unique molecules on pathogens.

Which protein presents viral antigens on the outer surface of cells? antibody T cell receptor MHC protein B cell receptor

MHC protein

Which of the following events occurs first when a wound that breaks the skin has occurred? Platelets release proteins that form clots and decrease bleeding. Mast cells secrete chemical messengers to regulate blood flow to the wound. Macrophages present bacterial proteins as antigens on their plasma membrane. Neutrophils secrete substances that degrade bacterial cell walls.

Platelets release proteins that form clots and decrease bleeding.

Choose the correct statement from the list below. The stomach has a high pH which allows for the activation of digestive enzymes. Mechanical digestion of proteins is more important than chemical digestion. Protein digestion begins in the small intestine with the activation of trypsinogen to trypsin Proteins that are consumed in the diet are absorbed as individual amino acids following digestion.

Proteins that are consumed in the diet are absorbed as individual amino acids following digestion.

Which event occurs first during atrial and ventricular diastole? The atria and ventricles contract simultaneously. The atria contract while blood flows into the relaxed ventricles. Blood flows into the relaxed atria while the ventricles contract. The atria and ventricles are relaxed, and blood flows into the atria.

The atria and ventricles are relaxed, and blood flows into the atria.

Why do the circulatory systems of land vertebrates have separate circuits to the lungs and to the rest of the body? Blood is pumped to the lungs to be oxygenated before being pumped to the rest of the body. The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body. The circuits increase the amount of surface area available for the diffusion of gases and nutrients in the body. Land vertebrates are bigger and require more tubing to reach all areas of the body.

The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.

Richard Smithells, of the University of Leeds, in England, examined the effect of vitamin supplementation on the risk of neural tube defects. Women who had had one or more babies with such a defect were put into two study groups. The experimental group consisted of those who were planning a pregnancy and began taking a multivitamin at least four weeks before attempting conception. The control group, who were not given vitamins, included women who declined them and women who were already pregnant. The numbers of neural tube defects resulting from the pregnancies were recorded for each group. This controlled study provided evidence that vitamin supplementation protects against neural tube defects, at least after the first pregnancy. Follow-up trials demonstrated that folic acid alone provided an equivalent protective effect. After folic acid supplementation became standard in the U.S., the frequency of neural tube defects dropped to an average of just 1 in 5,000 live births. The observed frequency in the experimental group of the Smithells study was much higher than 1 in 5,000. Select the two best explanations for why this would be. The individuals in the study were randomly assigned to the control or experimental group. The sample size in the Smithells study was small. The individuals in the study may have been predisposed to neural tube defects. The sample size in the Smithells study was large.

The sample size in the Smithells study was small. AND The individuals in the study may have been predisposed to neural tube defects.

Which event of the cardiac cycle occurs when systolic blood pressure is measured? The atria and ventricles are relaxed, and blood flows into the atria. The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria. The atria and ventricles contract simultaneously. The atria contract while blood flows into the relaxed ventricles.

The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria.

Which is a true statement about memory cells? They produce antibodies. They engulf antigens bound by antibodies. The first time an antigen is encountered, memory cells become plasma cells. They have a longer lifespan than plasma cells.

They have a longer lifespan than plasma cells.

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

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

Which of the following statements about blood circulation in the body is true? During one cardiac cycle, the two ventricles contract first, and then the two atria contract. As the right ventricle contracts, it sends oxygenated blood through the aorta to all tissues of the body. Valves prevent the backflow of blood into the atria and ventricles. Deoxygenated blood flowing through the pulmonary veins is carried to the right atrium.

Valves prevent the backflow of blood into the atria and ventricles.

Which of the following is a difference between vitamins and minerals? Vitamins are involved in regulating enzyme activity, but minerals are not. Minerals are obtained by an animal through dietary sources, but vitamins are made by the animal. Vitamins are organic molecules, but minerals are inorganic molecules. Vitamins and minerals are only obtained by digesting plants.

Vitamins are organic molecules, but minerals are inorganic molecules.

Stroke occurs when _____. See Concept 42.4 (Page 935) - a blood clot dislodges from a vein and moves into the lung, where it blocks a pulmonary artery - the walls of an artery in the leg accumulate deposits and lose their flexibility and elasticity - the pacemaker of the heart becomes defective, producing an irregular heartbeat - a blood clot enters and blocks one of the coronary arteries - a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue

a blood clot enters the cerebral circulation, blocking an artery and causing the death of brain tissue

If a mammal did not obtain enough iodine in its diet, you might expect ________. the animal to have weak bones a decrease in muscle function a decreased ability to produce thyroid hormones a decrease in enzyme function

a decreased ability to produce thyroid hormones

When digested, proteins are broken down into _____. glycerol only fatty acids only monosaccharides amino acids both glycerol and fatty acids

amino acids

Which secretion is not a barrier that prevents pathogens from entering the body? antigens mucus ear wax lysozyme

antigens

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 cytotoxic T cells → class II MHC molecule-antigen complex displayed → cytokines released → cell lysis B cell contact antigen → helper T cell is activated → clonal selection occurs complement is secreted → B cell contacts antigen → helper T cell activated → cytokines released

body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface

When digested, fats are broken down into _____. glycerol only fatty acids only monosaccharides amino acids both glycerol and fatty acids

both glycerol and fatty acids

During most daily activities, the human respiration rate is most closely linked to the blood levels of _____. carbon monoxide oxygen carbon dioxide nitrogen

carbon dioxide

Damage to the sinoatrial node in humans would ________. - have a direct effect on blood pressure monitors in the aorta - block conductance between the bundle branches and the Purkinje fibers - disrupt the rate and timing of cardiac muscle contractions - have a negative effect on peripheral resistance

disrupt the rate and timing of cardiac muscle contractions

Because the foods eaten by animals are often composed largely of macromolecules, animals need to have mechanisms for _____. regurgitation dehydration synthesis enzymatic hydrolysis demineralization

enzymatic hydrolysis

Which process is not required for an animal to obtain energy from food? Digestion. Excretion. Ingestion. Secretion.

excretion

True of false? The words "antigen" and "virus" are interchangeable.

false

True or False? The liver is a component of the alimentary canal.

false

True or false? One advantage of having a tube-like digestive tract is that digestion of all compounds can take place simultaneously down the tract.

false

True or false? The circulatory systems of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is a lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher-pressure circuit to the rest of the body.

false

True or false? The leukocytes of the innate immune system are B cells, macrophages, and neutrophils.

false

Your small intestine can absorb ____ without its being further digested. nucleic acid fat protein starch fructose

fructose

Among the following choices, which organism likely has the highest systolic pressure? mouse giraffe human hippopotamus

giraffe

The gastrovascular cavity differs from the alimentary canal in that only the gastrovascular cavity _____. stores food but does not digest it functions in digestion but not absorption has only a single opening absorbs food molecules but does not produce hydrolytic enzymes is capable of extracellular digestion

has only a single opening

In a humoral or antibody-mediated immune response, specific B cells are stimulated by helper T cells to transform into plasma cells that secrete antibodies. What would be an important feature added to the plasma cells during this transition process that allows them to better perform their function? increased rough endoplasmic reticulum for greater antibody production duplication of lysosomes in order to store the antibodies before transport duplication of specific gene sequences for the appropriate antibody increased antigen presentation on the surface of the plasma cells

increased rough endoplasmic reticulum for greater antibody production

From the capillaries of the abdominal organs and hind limbs, blood flows to the _____. right atrium left atrium aorta capillaries of the lungs inferior vena cava

inferior vena cava

The process of obtaining food is known as ________ and requires specialized feeding mechanisms. digestion ingestion excretion absorption

ingestion

Choose the list that presents the four stages of food processing in the order in which they naturally occur. absorption → digestion → ingestion → elimination ingestion → absorption → elimination → digestion ingestion → digestion → absorption → elimination ingestion → digestion → elimination → absorption digestion → ingestion → absorption → elimination

ingestion → digestion → absorption → elimination

Macrophages are _____. See Concept 43.1 (Page 956) short-lived cells that self-destruct soon after engulfing foreign invaders cells that induce the lysis of virus-infected body cells the best defense against parasites large, phagocytic cells that can leave the circulation and enter the tissues of the body antigen-presenting cells that originate from neutrophils

large, phagocytic cells that can leave the circulation and enter the tissues of the body

Voice sounds are produced by the _____. trachea diaphragm bronchioles larynx lungs

larynx

From the pulmonary veins, blood flows to the _____. right atrium left atrium aorta capillaries of the lungs inferior vena cava

left atrium

If you were to jog one kilometer a few hours after lunch, which stored fuel would you probably tap? fat stored in adipose tissue blood proteins liver glycogen and muscle glycogen muscle proteins

liver glycogen and muscle glycogen

Some human infants, especially those born prematurely, suffer serious respiratory failure because of _____. mutations in the genes involved in lung formation the sudden change from the uterine environment to the air lung collapse due to inadequate production of surfactant the overproduction of surfactants

lung collapse due to inadequate production of surfactant

Which of the following cells can engulf a pathogen? mast cells platelets cytokines macrophages

macrophages

Starch can be broken down into the disaccharide known as _____. lactose maltose glucose sucrose fructose

maltose

The primary functions of the _____ are to warm, filter, and humidify air. lungs trachea bronchus nasal cavity alveoli

nasal cavity

________ are cells of the mammalian innate immune response that help destroy tumors. B cells macrophages cytotoxic T cells natural killer cells

natural killer cells

Lymphocytes mature in the _____. I) spleen II) thymus III) bone marrow only I and II only I and III only II and III I, II, and III

only II and III

Mucus occurs in both the respiratory and digestive tracts. What is its main immunological function? destruction of pathogens because it is acidic physically trapping of pathogens increasing oxygen absorption sweeping away debris

physically trapping of pathogens

Starch is a type of _____. monosaccharide nucleotide polysaccharide disaccharide fatty acid

polysaccharide

Which of the following is crucial to activation of the adaptive immune response? phagocytosis of antibody-antigen complex by macrophages in the blood memory cells activation of complement proteins presentation of MHC (major histocompatibility complex)-antigen complex on a cell surface

presentation of MHC (major histocompatibility complex)-antigen complex on a cell surface

A significant contribution of intestinal bacteria to human nutrition is the benefit of bacterial ________. absorption of organic materials production of vitamins A and C production of vitamin K recovery of water from fecal matter

production of vitamin K

Blood returns to the heart via the _____. aorta pulmonary arteries pulmonary veins aorta and pulmonary arteries aorta and pulmonary veins

pulmonary veins

From the superior vena cava, blood flows to the _____. right atrium left atrium aorta capillaries of the lungs inferior vena cava

right atrium

Which structure is not part of the alimentary canal? Salivary glands. Esophagus. Stomach. Mouth.

salivary glands

Which of the following organs is correctly paired with its function? pancreas: starch digestion small intestine: polysaccharide digestion large intestine: bile production stomach: fat digestion

small intestine: polysaccharide digestion

Among mammals, it is generally true that _____. after leaving the oral cavity, the bolus enters the larynx all types of foods begin their enzymatic digestion in the mouth the epiglottis prevents swallowed food from entering the trachea the trachea leads to the esophagus and then to the stomach

the epiglottis prevents swallowed food from entering the trachea

The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels? the pulmonary vein and the aorta the pulmonary artery and the inferior vena cava the pulmonary vein and the superior vena cava the veins from the right and left legs

the pulmonary vein and the superior vena cava

The eyes and the respiratory tract are both protected against infections by _____. the release of slightly alkaline secretions the secretion of complement proteins the secretion of lysozyme onto their surfaces interferons produced by immune cells

the secretion of lysozyme onto their surfaces

Which of the following should be the same in identical twins? the set of T cell antigen receptors produced the set of antibodies produced the set of major histocompatibility (MHC) molecules produced the susceptibility to a particular virus

the set of major histocompatibility (MHC) molecules produced

Which structure is not a component of the adaptive immune system? thymus tissues lymphatic ducts spleen

tissues

True or false? B cells were originally isolated from the bursa in chickens, and their function is to produce antibodies; T cells were originally isolated from the thymus in mice, and their functions include killing host cells that are being infected with a virus.

true

True or false? The site of inflammation may become swollen due to the increased numbers of cells and fluids at the site and painful due to signals from pain receptors.

true

A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. To travel from the artery to the thumb and then back to the left ventricle, this red blood cell must pass through _____. four capillary beds one capillary bed two capillary beds three capillary beds

two capillary beds

A strain of fruit fly lacks the ability to produce Dicer-2 protein. You might expect this strain to be more susceptible to ________ infections. bacterial fungal protozoan viral

viral

What is the main component of gastric juice? water hydrochloric acid inactive pepsin amylase bile

water

An advantage of gas exchange in fresh water, compared with gas exchange in air, is that _____. See Concept 42.5 (Page 937) - the respiratory surface does not have to be as extensive in water - water is easier to move over the respiratory surface - ventilation requires less energy in water - water loss through evaporation across the respiratory surface can be minimized - water usually contains a higher concentration of oxygen than air

water loss through evaporation across the respiratory surface can be minimized