Mastering Biology Test 3

Which principle of heat exchange is the most important explanation for why birds look larger in colder weather because they fluff their feathers?

Fluffing creates a pocket of air near the bird that acts as insulation.

Pepsinogen is converted to its active form in the stomach by ________.

HCL

What is the importance of the mucus that are released by salivary glands?

They are glycoproteins that make food slippery enough to slide easily through the esophagus.

Interstitial fluid is _____.

a common site of exchange between blood and body cells

All types of muscle tissue have

interactions between actin and myosin

For ingested foods, the first opportunity for enzymatic digestion occurs in the _____.

mouth

The cells lining the air sacs in the lungs make up a _____.

simple squamous epithelium

Among mammals, it is generally true that

the epiglottis prevents swallowed food from entering the trachea

Organisms maintain dynamic homeostasis (internal balance) through behavioral and physiological mechanisms. Which of the following statements is an accurate explanation of a negative feedback mechanism used by animals to regulate body temperature?

A ground squirrels hypothalamus detects changes in environmental temperatures and responds by activating or suppressing metabolic heat production.

Which of the following best describes an artery?

Arteries carry blood away from the heart.

If you were to view a sample of animal tissue under a light microscope and notice an extensive extracellular matrix surrounding a tissue, which tissue type would you most suspect?

Connective

The pancreas is involved in the digestion of _____.

I, II, III, and IV

Which organ system is responsible for protection against injury, infection, and dehydration?

Integumentary system

All animals, whether large or small, have ____

Most of their living cells surrounded by an aqueous medium.

If you place a small piece of a cracker on your tongue, what would you expect to happen?

Salivary amylase degrades the starch from the cracker into maltose

Which of the following animals is correctly paired with its feeding mechanism?

Snake- Bulk feeder

Which of the following is a correct statement about an organism and its environment?

The interstitial fluid is the exchange medium between body cells and the circulatory system in vertebrate animals.

Why did scientists originally hypothesize that proteolytic enzymes such as pepsin and trypsin are secreted in inactive form?

These proteolytic enzymes, in active form, would digest the very tissues that synthesize them.

Why do the cells of the digestive system secrete proteolytic enzymes, such as pepsin, in their inactive forms?

These proteolytic enzymes, in active form, would digest the very tissues that synthesize them.

What is the importance of the mucins that are released by salivary glands?

They are glycoproteins that make food slippery enough to slide easily through the esophagus

Which of the following is an example of negative feedback?

When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases.

Which of the following primarily involves heat transfer by convection?

You roll down the car window to allow the cool breeze to blow through.

You are studying a large tropical reptile that has a high and relatively stable body temperature. How would you determine whether this animal is an endotherm or an ectotherm?

You subject this reptile to various temperatures in the lab and find that its body temperature and metabolic rate change with the ambient temperature. You conclude that it is an ectotherm.

In a physiological system operating with positive feedback, _____.

a change in a variable will amplify rather than reverse the change

Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have _____.

a closed circulatory system

Bone consists of

a mixture of hardened collagen and minerals.

Stomach cells are moderately well adapted to the acidity and protein-digesting activities in the stomach by having _____.

a thick, mucous secretion and active mitosis of epithelial cells

The large surface area in the gut directly facilitates _____.

absorption

The process by which digested dietary substances cross cell membranes to be used by the body is known as ________.

absorption

In many animals, fat is stored in specialized cells in the ________.

adipose tissue

An advantage of a complete digestive system over a gastrovascular cavity is that the complete system _____.

allows for specialized regions with specialized functions

The Bile salts

emulsify fats in the duodenum

Folic acid supplements have become especially important for pregnant women because _____.

folic acid deprivation is associated with neural tube abnormalities in a fetus

Which of the following would increase the rate of heat exchange between an animal and its environment?

wind blowing across the body surface

Which statement regarding the mammalian heart is correct?

In the adult heart, blood in the right chambers of the heart cannot enter the left chambers without passing through the lungs.

Which statement about the gas exchange system in fish is correct?

It enables oxygen to diffuse from the water into the blood over the entire length of the gill capillaries.

When the body's blood glucose level rises, the pancreas secretes insulin and, as a result, the blood glucose level declines. When the blood glucose level is low, the pancreas secretes glucagon and, as a result, the blood glucose level rises. Such regulation of the blood glucose level is the result of _____.

Negative feedback

Some animals have no gills when young, but then develop gills that grow larger as the animal grows larger. What is the reason for this increase in gill size?

Relative to their volume, the young have more surface area across which they can transport all the oxygen they need.

Which of the following statements comparing respiration in fish and in mammals is correct?

The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.

Which statement about oxygen in fish gills is correct?

The partial pressure of oxygen in blood increases as it flows through gill capillaries.

The partial pressure of oxygen at a particular point in the bloodstream is 100 mm Hg. Under what circumstance will there be a net diffusion of oxygen from the water into the bloodstream at this location?

There will be a net diffusion of oxygen from the water into the bloodstream only if the partial pressure of oxygen in the water is greater than 100 mm Hg.

Although having evolved independently, the tracheal tubes of mammals and insects are both supported by rigid tissues. The trachea of a mammal is supported by cartilage, and the tracheae of an insect are supported by chitin. What selective pressure most likely led to the convergent evolution of these respiratory structures?

When air is the respiratory medium, there is a greater risk that the tracheal tubes will collapse.

Ingested dietary substances must cross cell membranes to be used by the body. This process is known as _____.

absorption

Most land-dwelling invertebrates and all of the amphibians _____.

are ectothermic organisms with variable body temperatures

Most land-dwelling invertebrates and all of the amphibians ________.

are ectothermic organisms with variable body temperatures

To survive, all animals must _____.

balance consumption of food with use and storage of nutrients

An oil-water mixture works as an insecticidal spray against mosquitoes and other insects because it _____.

blocks the openings into the tracheal system

The smallest airway through which inspired air passes before gas exchange occurs in the mammalian lungs is the _____.

bronchiole

The "essential nutrients" for proper human nutrition include _____.

calcium, sodium, potassium, and other minerals

You discover a new species of bacteria that grows in aquatic environments with high salt levels. While studying these bacteria, you note that their internal environment is similar to the salt concentrations in their surroundings. You also discover that the internal salt concentrations of the bacteria change as the salt concentration in their environment changes. The new species can tolerate small changes in this way, but dies from large changes because it has no mechanism for altering its own internal salt levels. What type of homeostatic mechanism is this species using to regulate its internal salt levels?

conformation

The body tissue that consists largely of material located outside of cells is _____.

connective tissue

Countercurrent exchange in the fish gill helps to maximize _____.

diffusion

Which of the following organisms has no specialized respiratory structures?

earthworms

If you gently bend your ear, and then let go, the shape of your ear will return because the cartilage of your ear contains_____.

elastic fibers

Bats and hummingbirds are examples of _____.

endotherms that are also poikilotherms

Negative feedback is a method of homeostatic control that _____.

ensures that conditions in an organism do not vary too much above or below their set points

There are advantages and disadvantages to adaptations. Animals that are endothermic are likely to be at the greatest disadvantage in _____.

environments with variable and limited food sources

Because the foods eaten by animals are often composed largely of macromolecules, animals need to have mechanisms for _____.

enzymatic hydrolysis

You are looking through a microscope at a slide of animal tissue and see a single layer of flat, closely packed cells that cover a surface. This specific tissue is most likely _____.

epithelial

Most of the exchange surfaces of multicellular animals are lined with _____.

epithelial tissue

Elephants can often be observed cooling off by spraying water over their bodies with their trunks. What type of heat exchange is occurring?

evaporation

Sweating allows a person to lose heat through the process of _____.

evaporation

The panting responses that are observed in overheated birds and mammals dissipate excess heat by _____.

evaporation

In a well-fed human eating a Western diet, the richest source of stored chemical energy in the body is _____.

fat in adipose tissue

Animals that migrate great distances would obtain the greatest energetic benefit of storing chemical energy as _____.

fats

The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the _____.

fishes

To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a(n) _____.

four-chambered heart

In which of the following organisms does blood flow from the pulmocutaneous circulation to the heart before circulating through the rest of the body?

frogs

In which of the following animals are the blood and the interstitial fluid considered to be the same body fluid?

grasshoppers

Mechanical digestion, the process of breaking down large chunks of food into smaller pieces, is important because smaller pieces of food ________.

have more surface area for chemical digestion than do larger pieces of food

Nutrient-rich blood from the intestine is carried through the ________ to the liver.

hepatic portal vein

The body's automatic tendency to maintain a constant and optimal internal environment is termed _____.

homeostasis

The temperature-regulating center of vertebrate animals is located in the _____.

hypothalamus

Villi and microvilli in the small intestine _____.

increase the surface area to increase the efficiency of nutrient absorption

Upon activation by stomach acidity, the secretions of the parietal cells _____.

initiate the chemical digestion of protein in the stomach

In a cool environment, an ectotherm is more likely to survive an extended period of food deprivation than would an equally sized endotherm because the ectotherm _____.

invests little energy in temperature regulation

Blood is best classified as connective tissue because _____.

its cells are separated from each other by an extracellular matrix

Which of the following organs is incorrectly paired with its function?

large intestine-bile production

Which of the following represents the correct flow of air into the lung of a mammal?

larnyx → trachea → bronchi → bronchioles → alveoli

Homeostasis is the _____.

maintenance of a relatively constant and optimal internal environment

The absorption of fats differs from that of carbohydrates in that _____.

most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood

The four major categories of tissues are _____.

nervous, epithelial, connective, and muscle

The metabolic breakdown of specialized brown fat deposits in certain animals is substantially increased during ________.

non shivering thermogenesis

The metabolic breakdown of specialized brown fat depots in certain animals is substantially increased during _____.

nonshivering thermogenesis

Which pair correctly associates a physiological process with the appropriate vitamin?

normal vision - vitamin A

In an open circulatory system, blood is _____.

not always confined to blood vessels and is under lower pressure than in closed circulatory systems

Which of the following is not a major activity of the stomach?

nutrient absorption

The gastrovascular cavity differs from the alimentary canal in that only the gastrovascular cavity _____.

only has a single opening

The active ingredient orlistat acts to decrease the amount of fat that is absorbed by attaching to enzymes that digest fat. Which of the following are potential targets of orlistat?

pancreatic lipase

Over-the-counter medications for acid reflux or heartburn block the production of stomach acid. Which of the following cells are directly affected by this medication?

parietal cells

The mammalian trachea and esophagus both connect to the _____.

pharynx

Once labor begins in childbirth, contractions increase in intensity and frequency, causing more contractions to occur until delivery. The increasing labor contractions of childbirth are an example of which type of regulation?

positive feedback

A significant contribution of intestinal bacteria to human nutrition is the benefit of bacterial _____.

production of vitamin K

The digestion of ________ begins in the stomach.

protein

To prepare flight muscles for use on a cool morning, hawkmoths _____.

rapidly contract and relax these muscles to generate metabolic warmth

What would be the consequences if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, the out the mouth? This reversal of water flow would _____.

reduce efficiency of gas exchange

A countercurrent heat exchanger enables an animal to _____.

reduce the loss of body heat to the environment

The lower esophageal sphincter surrounds the upper opening into the stomach. If this sphincter failed to properly constrict, there might be a problem with _____.

regurgitation of acidic stomach contents into the esophagus, commonly called "heartburn"

Connective tissues typically have _____.

relatively few cells and a large amount of extracellular matrix

An example of an ectothermic organism that has few or no behavioral options when it comes to its ability to adjust its body temperature is a _____.

sea star living deep in the ocean

Of the following choices, the epithelium with the shortest diffusion distance is _____.

simple squamous epithelium

Food moves along the digestive tract as the result of contractions by _____.

smooth muscle

The type of muscle tissue surrounding the intestines and blood vessels is _____.

smooth muscle

In the digestive system, peristalsis is _____.

smooth muscle contractions that move food along the esophagus

Digestive secretions with a pH of 2 are characteristic of the _____.

stomach

Which of the following organs is correctly paired with its function?

stomach - protein digestion

Which of the following develops the greatest pressure on the blood in the mammalian aorta?

systole of the left ventricle

Examine the figure above. Near a goose's abdomen, the countercurrent arrangement of the arterial and venous blood vessels causes the _____.

temperature difference between the contents of the two sets of vessels to be minimized

If an organism was discovered that had no epithelial tissues, it would require adaptations to maintain homeostasis in which of the following areas? The organism would require adaptations _____.

that would prevent water loss from the body in a terrestrial environment

An example of a properly functioning homeostatic control system is seen when _____.

the kidneys excrete salt into the urine when dietary salt levels rise

The circulatory systems of bony fishes, rays, and sharks are most similar to _____.

the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber

Positive feedback differs from negative feedback in that _____.

the positive feedback's effector responses are in the same direction as the initiating stimulus rather than opposite of it

Circulatory systems compensate for _____.

the slow rate at which diffusion occurs over large distances

Certain nutrients are considered "essential" in the diets of some animals because _____.

these animals are not able to synthesize these nutrients

Fat digestion yields fatty acids and glycerol, whereas protein digestion yields amino acids; both digestive processes _____.

use water molecules when breaking bonds (hydrolysis)

Flying insects typically _____.

utilize high numbers of mitochondria in flight muscles

The thin horizontal arrows in the figure above show that the _____.

warmer arterial blood transfers heat to the cooler venous blood

Countercurrent exchange is evident in the flow of _____.

water across the gills of a fish and the blood within those gills

An advantage of gas exchange in fresh water, compared with gas exchange in air, is that _____.

water loss through evaporation across the respiratory surface can be minimized