Bio Unit 4

Place the following digestion events in sequential order

1.) in the mouth, salivary amylase breaks down complex carbohydrates during chewing. 2.) once the food is swallowed and passes through the esophagus into the stomach, the stomach secretes both HCl and pepsinogen. The HCl activates the pepsinogen into pepsin, which breaks down large proteins into polypeptides (shorter chains of amino acids). 3.) after digestion in the stomach, the bolus of food moves into the small intestine where the gall bladder secretes bile salts (produced in the liver, stored in the gall bladder) to digest lipids, and the pancreas secretes pancreatic amylyase and other digestive enzymes. these enzymes cause further digestion of material into individual components such as polypeptides broken down into individual amino acids. these nutrients are then absorbed into the blood stream (or moved into the lymph in the case of lipids) in the small intestine. 4.) after absorption of nutrients in the small intestine, the digested material moves into the large intestine where water is reabsorbed and the material is compacted for elimination.

The descending limb of the loop of Henle is permeable to -----, and the thin ascending limb is permeable to -----. water; Na+ and Cl− Na+ and Cl−; water water; urea glucose; wate

A the descending limb is the portion closer to the glomerulous; the ascending limb is closer to the collecting duct. the descending limb is permeable to water and impermeable to salts; water leaves the tubule due to the higher concentration of solutes in the medulla. the ascending limb is impermeable to water and permeable to salts; salts leave due to either active or passive transport (depending on the location in the tubule)

Ectotherms are most likely to to use these methods of heat gain: conduction convection radiation internal metabolism

A and C the most common sources of heat for ectotherms are basking in the sun (radiation) and lying on rocks and other objects warmed by the sun (conduction). internal metabolism as a source of heat is rare in ectotherms but does occur; some flying insects 'shiver' to warm up muscles before flight. shivering generates large amounts of heat as a result of metabolic reactions.

Root pressure can best be described as A high pressure potential driven by accumulation of ions and water by osmosis The loss of water molecules from menisci, creating a large negative pressure The adhesion of water molecules to the sides of xylem, creating a pull upward, and by cohesion with water molecules below The movement of water from a region of low water potential to high water potential

A high pressure potential driven by accumulation of ions and water by osmosis

34) Hummingbirds have extremely high metabolic rates when active, but exhibit a drop in metabolic rate of almost 95% during cold nights. Hummingbirds are: A) Endothermic; Heterothermic B) Ectothermic; Heterothermic C) Ectothermic; Homeothermic D) Endothermic; Homeothermic

A) Endothermic; Heterothermic

Increasing which of the following will also increase blood pressure? Cardiac output Heart rate Stroke volume Total peripheral resistance

A, B, C, and D The heart rate (HR), also called the pulse, is the number of beats per minute The stroke volume (SV) is the amount of blood pumped in a single contraction The cardiac output (CO) is the volume of blood pumped into the systemic circulation per minute and depends on both the heart rate and stroke volume The blood flow through a particular vessel is related to the pressure and resistance in the vessel. Total peripheral resistance (TPR) is a measure of the total resistance across all blood vessels. Blood flow must equal total cardiac output CO = SV x HR BF = P/TPR CO = BF thus since CO = BF, increasing any of the above parameters will increase blood pressure.

Strenuous exercise results in dilation of arterioles in working muscles to increase blood flow to muscles and to skin capillaries to promote body cooling. Why doesn't blood pressure drop as a result? A. Constriction of other arterioles and capillaries - such as those in the digestive tract help balance out the dilation B. Increased cardiac output in terms of heart rate helps balance out the dilation C. Increased cardiac output in terms of blood volume helps balances out the dilation

A. Constriction of other arterioles and capillaries - such as those in the digestive tract help balance out the dilation B. Increased cardiac output in terms of heart rate helps balance out the dilation C. Increased cardiac output in terms of blood volume helps balances out the dilation

Match the enzyme to the type of nutrient it breaks down. 1st choice proteins 2nd choice nucleic acids 3rd choice fats 4th choice fats 5th choice proteins 6th choice carbohydrates

A. amylase 1. carbohydrates B. bile salts 2. fats C. pepsin 3. proteins D. lipase 4. fats E. trypsin 5. proteins F. nuclease 6. nucleic acids

Which of the following is an advantage of a complete digestive tract? A. Large pieces can be ingested B. Digestive steps co-occur in the same place C. A separate opening is not needed for waste D. Digestive enzymes are not needed

A.Large pieces can be ingested

33) Aldosterone is secreted in response to a drop in blood volume. How is it different from how ADH acts? A) ADH acts in response to an increase in blood volume. B) ADH acts in response to a decrease in blood osmolarity. C) ADH acts in response to an increase in blood osmolarity. D) ADH constricts the arterioles as well as acts on brain. E) None of the above

ADH acts in response to an increase in blood osmolarity

Which of the following best describes the energy requirements for movement of sugar through phloem? Energy is required for production of glucose from carbon dioxide; movement of sugar through phloem does not require additional input of energy Water is actively pumped into phloem to dilute the high sugar concentration and create turgor pressure required for bulk flow Sugar moves between sieve tube cells as a result of ATP-driven transporters ATP pumps and cotransport are required for loading companion cells at the sugar source All of the above except A

ATP pumps and cotransport are required for loading companion cells at the sugar source

Where does the mass of a tree come from? Soil Sunlight Air Water

Air

Match the valve status to the stage in the cardiac cycle. A. Atria in systole 1. AV valve open and SL valve closed B. Ventricles in systole 2. AV valve closed and SL valve open C. Atria and ventricles both in diastole 3. AV valve open and SL valve closed

Atria in systole - AV valve open and SL valve closed Ventricles in systole - AV valve closed and SL valve open Atria and ventricles both in diastole - AV valve open and SL valve closed

Which of the following correctly describes why water is more difficult to respire in compared to air? A. Water is warmer than air, and thus holds less oxygen. B. Water is about 1000x more dense than air, and thus requires more energy to ventilate the respiratory surface (inhale/exhale). C. Water has a higher partial pressure of O2, and thus O2 constantly diffuses into the air (away from aquatic organisms). D. Respiratory surfaces work better in drier conditions, not in moist (or wet) conditions.

B air is less dense and thus takes less work (energy) to move through the respiratory organ. water has a lower partial pressure of oxygen than air does. warmer water holds less oxygen than colder water, but the temperature of a body of water is often cooler than the air. respiratory surfaces tend to be lined in thin mucus, and thus drier air conditions cause drying of these surfaces which can interfere with respiratory function.

The kidney has more collecting ducts than distal tubules. True False

B each nephron empties into a single collecting duct, but a single collecting duct is connected to multiple nephrons. the collecting ducts flow to the ureter. each kidney has a single ureter. the two ureters empty into the single bladder.

In a saltwater environment, chloride secretory cells in the gills move salts ______ the fish's blood. into out of

B the seawater is hypertonic to marine fishes (they are hypotonic to the seawater). this means that the water potential in the seawater is lower than the water potential in the fish, and thus they are constantly losing water and gaining solutes. marine fish must therefore constantly drink seawater (and actively pump out solutes) to maintain their water/solute balance.

29) Which of the following is the primary fitness cost to creating waste as ammonia? A) Requires development of Malpighian tubes B) Requires significantly more water C) It is insoluble in water and requires energy to excrete D) It can only be generated at warm temperatures E) None of the above

B) Requires significantly more water

32) Which of the following is NOT involved in reabsorption of solutes and water in the loop of Henle? A) countercurrent exchange B) active transport of water C) active transport of sodium D) passive transport of sodium

B) active transport of water

Which of the following statements regarding closed vs open circulatory systems is FALSE? A. Circulatory fluid exits the vessels and directly bathes cells within body cavities in open circulatory systems B. Circulatory fluid can be pumped farther distances in open circulatory systems than in closed circulatory systems C. Circulatory fluid speed and localized pressure can be effecieintly controlled in closed but not open circulatory systems D. All vertebrates and some invertebrates have closed circulatory systems E. Circulatory fluid is the same as interstitial fluid in open circulatory systems; they are different fluids in closed circulatory systems

B. Circulatory fluid can be pumped farther distances in open circulatory systems than in closed circulatory systems open circulatory systems are common in invertebrates. vertebrates and some invertebrates (such as annelids and cephalopods) have closed circulatory systems. all circulatory systems have three essential components: a muscular pump (heart), a circulatory fluid (blood or hemolymph), and a series of tubes that the fluid moves through (vessels). the differences between an open and closed circulatory system are that a) the circulatory fluid does not remain within the blood vessels in an open circulatory system and thus b) the circulatory fluid is also the interstitial fluid (fluid in direct contact with the body cells). additional consequences of the open circulatory system are that blood flow rates are slower and blood pressure is not as high as in a closed circulatory system, because the hemolymph moves throughout the entire body volume rather than staying enclosed within vessels. organisms with open circulatory systems can control localized pressure and blood flow to some extent, by compressing sections of the body cavity due to muscle contraction or via additional series of tubes (present in crustaceans) that can affect localized direction of blood flow; however, these adaptations are less efficient at regulating pressure and blood flow compared to a closed system

The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why? C4 plants allow less water loss, but CAM plants allow more water loss. C4 compromises on water loss and CAM compromises on photorespiration. CAM plants allow more water loss, while C4 plants allow less CO2 into the plant. Both minimize photorespiration but expend more ATP during carbon fixation. Each one minimizes both water loss and rate of photosynthesis.

Both minimize photorespiration but expend more ATP during carbon fixation.

O2 binding by hemoglobin is cooperative. Which model is more effective for delivery of oxygen to tissues during exercise, when O2 demands are high?

By comparing these two graphs at a low tissue partial pressure (for example, 20 mm Hg), you can see in the cooperative binding model that oxygen saturation for hemoglobin is approximately 5%. in contrast, in the non-cooperative binding model, the oxygen saturation for hemoglobin is approximately 20% at this same partial pressure. this means in the non-cooperative binding model the hemoglobin keeps more oxygen rather than delivering it to tissues in need.

Which animal has a double circulatory system? A. earthworm B. fish C. snake D. octopus

C in fish (single circuit), blood leaves the heart then flows through the gills then directly to the body tissues. there is a substantial drop in both blood pressure once the blood passes through the gills, so blood moving into the tissues does not move as quickly as it does right after exiting the heart. because fish live in a buoyant environment where the effects of gravity are minimized, this lower pressure is still sufficient to move blood efficiently to the body tissues. in contrast, in terrestrial organisms, this decreased pressure would not be sufficient to effectively reach the rest of the body due largely to the effects of gravity. thus the additional chamber of the heart increases both the pressure of the blood entering the body tissues (systemic circuit). as a terrestrial vertebrate, snakes have a double circulatory system for the evolutionarily selective reasons described above.

An aquatic animal with internal solute concentration of about 500 mOsm L-1 is placed in a fluid of solute concentration of about 700 mOsm L-1. Which of the following results is consistent with osmoregulation? Passively taking in salts to change its tissue osmolarity to 700 mOsm L-1. Pumping in salts to keep tissues at 500 mOsm L-1. Pumping out salts to keep tissues at 500 mOsm L-1. Pumping out salts to change its tissue osmolarity to 700 mOsm L-1. None of the above.

C in this example, there is a lower solute concentration in the animal than in the environment. this means the animal is hypotonic to the environment, or the water potential is lower in the envrionment than in the animal. thus water will tend to move OUT of the animal and into the environment, and salts will tend to move IN to the animal and out of the environment. the animal can combat this effect by taking in large quantities of the solution to bring in water, then using a lot of energy to actively pump the incoming salts out of its body and back into its environment.

35) Which of the following is most likely how a poikilotherm thermoregulates? A) Insulation B) Circulatory adaptations C) Behavioral adaptations D) Metabolic heat production E) Perspiring

C) Behavioral adaptations

24) Which of the following represents the correct flow of blood through the structure of the heart? A) Left atrium>Right atrium>Left ventricle>Right ventricle B) Right atrium>Left atrium>Right ventricle>Left ventricle C) Right atrium>Right ventricle>Left atrium>Left ventricle D) Left atrium>Right ventricle>Right atrium>Left ventricle E) Left atrium>Left ventricle>Right atrium>Right ventricle

C) Right atrium>Right ventricle>Left atrium>Left ventricle

31) Beavers have relatively little need to conserve water and could therefore be expected to have _______ than humans do. A) Fewer nephrons B) Longer nephron loops C) Shorter nephron loops D) Longer collecting ducts

C) Shorter nephron loops

Which of the following promotes oxygen release from hemoglobin? A. A decrease in temperature in body tissue B. A decrease in CO2 levels in body tissue C. A decrease in pH in body tissue D. A decrease in carbonic anhydrase in RBCs

C. A decrease in pH in body tissue the Bohr shift causes the hemoglobin-oxygen equilibrium curve (the plot comparing oxygen saturation of hemoglobin against partial pressure of oxygen in the body tissues) to shift toward the right. this means that hemoglobin becomes MORE likely to 'give up' oxygen at any particular partial pressure of oxygen in the body tissue (decreases the affinity of hemoglobin for oxygen). this shift occurs because of lower pH.

The difference between positive pressure ventilation (PPV) and negative pressure ventilation (NPV) is that: A. in PPV, organisms exchange gases only during inhalation; in NPV, organisms exchange gasses only during exhalation B. in PPV, respiration is coupled to a circulatory system; in NPV, respiration occurs through direct gas exchange with tissues C. PPV occurs when air is pushed into the respiratory organ; NPV occurs when air is pulled into the respiratory organ D. PPV occurs only in animals with gills or tracheae, NPV occurs only in animals with lungs

C. PPV occurs when air is pushed into the respiratory organ; NPV occurs when air is pulled into the respiratory organ

Why are plants like the venus fly trap and pitcher plant carnivorous? A. The need additional carbon than is present in the soil B. They need additional protein than what is present in the soil C. They need additional mineral nutrients than what is present in the soil D. They need additional energy than what is present in the soil

C. They need additional mineral nutrients than what is present in the soil plants get carbon from carbon dioxide and energy from the sun. they synthesize their own amino acids (building blocks of proteins) from carbon and other nutrients. they also use other nutrients for many other biological functions. these other nutrients are typically minerals obtained from the soil such as nitrogen, potassium, calcium, etc. nitrogen is often the most critically limiting nutrient, as it can only be made biologically available by a few species of bacteria. thus plants which live in extremely nitrogen-poor environments often have carnivorous adaptations to provide an additional sources of nitrogen from other living organisms.

Given your results from the baby's spit up/vomit, you run an MRI right after the baby ate. This allows you to determine whether there is a blockage in the organ that generates that enzyme (physical), or if there is a problem with the enzymes themselves (chemical). Which of the following results would help you decide whether the problem is solely physical or chemical? A. Chemical: The enzyme was spit up, but the digestive path appears normal B. Physical: The enzyme was spit up, but the digestive path appears normal C. Chemical: The enzyme was spit up, but the digestive path has a lump stopping movement of food D. Physical: The enzyme was not spit up, but the digestive path has a lump stopping movement of food E. Chemical: The enzyme was not spit up, and the digestive path appears normal

Chemical: The enzyme was spit up, but the digestive path appears normal Physical: The enzyme was not spit up, but the digestive path has a lump stopping movement of food

Rank the following nitrogenous waste products, from LEAST to MOST amount of water lost during excretion: urea uric acid ammonia

Correct Answer uric acid < urea < ammonia because it is a base and therefore alters pH, ammonia is highly toxic to cells. thus ammonia must be heavily diluted in water for excretion. urea requires additional metabolic reactions to produce from ammonia and therefore is more energetically 'expensive' to produce, however, it is beneficial because its reduced toxicity means it does not have to be diluted in as much water for excretion. uric acid requires even more reactions to produce from urea, and is thus more 'expensive' to produce than urea; however, it is beneficial because it is nearly insoluble in water and requires almost no water for elimination. this is highly advantageous for animals that live in environments such as deserts where whater is extremely limited or even unavailable.

All of the following adaptations except for ___________ are seen in desert animals. shells, scales, and thick skin nocturnal activity pattern conservation of metabolic water nitrogenous waste excreted as ammonia production of concentrated urine

D pretty much any adaptation that decreases loss of water is seen in desert animals. because ammonia is a base is highly toxic to cells, it must be heavily diluted in water for excretion. many desert animals, including desert mammals, convert nitrogenous wastes to uric acid. uric acid is the most energentically costly form of nitrogenous waste disposal; however, it is beneficial because it is nearly insoluble in water and requires almost no water for elimination. this is highly advantageous for animals that live in environments such as deserts where whater is extremely limited or even unavailable.

26) If cardiac output drops, then A) The product of the heart rate and stroke volume decreases B) Blood flow must decrease C) Blood flow must increase D) A and B E) A and C

D) A and B

23) Which of the following is NOT true of gas, nutrient, and fluid exchange between capillaries and body tissues? A) Blood enters the capillary from the arteriole B) Blood pressure is higher entering than leaving the capillary C) Excess fluid from the exchange enters the lymphatic duct D) Blood pressure is less in the capillary than in the tissues E) Osmotic pressure is constant across the capillary

D) Blood pressure is less in the capillary than in the tissues

25) Which of the following is FALSE regarding electrical signals in the heart? A) The cells of the sinoatrial node initiate heartbeat B) The atrioventricular node temporarily delays the electrical signal C) The Perkinje fibers transmit electrical signal for contraction D) The signal passes through the ventricles and pauses before the atria E) All of the above are true

D) The signal passes through the ventricles and pauses before the atria

Based on function, which region of the mammalian heart should have the thickest walls (be the most muscular)? A. The right atrium B. The left atrium C. The right ventricle D. The left ventricle

D. The left ventricle atria pump blood into ventricles; ventricles pump blood into arteries. ventricles have thicker walls (more muscle cells) than atria; their contractions are stronger to pump blood much farther. the pulmonary circuit (controlled by the right side of the heart) is relatively short compared to the systemic circuit (controlled by the left side of the heart), which must reach the entire body and return to the heart over a much longer distance. thus natural selection on the heart musculature to reach this much larger distance has resulted in a thicker (more muscular) left ventricle compared to any other compartment of the mammalian heart.

As their doctors, you ask whether the baby has spat up or vomited at all. The parents confirm this happens regularly, but they aren't sure what the substance is that the baby is ejecting. You ask them to feed the child again, and take a sample of the mystery substance that the baby ejects. Which of the following substances could you check for to narrow down the organ where the issue might be happening? A. Blood B. Salivary Amylase C. Lingual Lipase D. Bile

D. Bile Blood, although scary to see, does not narrow down which organs, as blood can be found everywhere. Saliva in the mouth contains both amylase and lipase, so if liquid is coming back out of the mouth, it could pick up those enzymes. Only bile lets you know that the substance has passed further down in the digestive system.

A friend wants better hair, skin, and nails. Assuming your friend has a deficiency in a vitamin, which of the following supplements should you suggest they try? A. Magnesium B. Vitamin C C. Iodine D. Biotin E. Iron

D. Biotin

Which of the following is NOT a reason that an animal's gut is a favorable habitat for mutualistic microorganisms? A. Constant temperature B. Ready supply of nutrients C. Inhospitable conditions for many micro-competitors D. Easy access to bloodstream

D. Easy access to bloodstream the gut does not provide easy access to the bloodstream except in cases where the lining of the gut becomes compromised. this can occur in cases of infection, where the tight junctions between intestinal cells becomes compromised.

How does mineral mobility affect the symptoms of deficiency in plants? Deficiency of a mobile nutrient usually affects older organs more than young ones Deficiency of a mobile nutrient usually affects younger organs more than older ones

Deficiency of a mobile nutrient usually affects older organs more than young ones

Which of the following types of organisms is/are isotonic to its environment (does not osmoregulate)? Amphibians Freshwater fish Marine fish Terrestrial vertebrates Marine jellyfish and sponges

E of these options, only marine jellyfish and sponges do not osmoregulate. most biological reactions require precise pH and solute concentrations, and do not occur efficiently if conditions move outside of these specific parameters. because the seawater is fairly stable in osmolarity (does not have large swings in solute concentration), these animals are in a relatively stable environment where conditions do not change much. this means that even though they are osmoregulators.

Veins always carry deoxygenated blood. True False

False a vein is any vessel that carries blood into the heart; and artery is any vessel that carries blood away from the heart. the artery that carries blood from the heart to the lungs contains deoxygenated blood, and the vein that carries blood from the lungs to the heart carries oxygenated blood.

There are no valves at the point where blood flows from the ventricles into arteries. True False

False the atrioventricular valves are located between the atria and the ventricles. this valve is open as blood flows and is pumped from the atria into the ventricles. as the ventricles contract, blood is forced against the atrioventricular valves causing them to slam shut. this causes the 'lub' sound of the heartbeat. contraction of the ventricles forces blood through the semilunar (pulmonary and aortic) valves. as the ventricle relaxes, the blood in the aortic and pulmonary arteries slams backward against the seminlunar valves, causing them to shut. this causes the 'dub' sound of the heartbeat. there are no valves in the heart at the point where the veins join the atria

Blood capillaries must reabsorb all the fluid they emit, or edema (swelling) will occur. A. True B. False

False B because of osmotic pressure and solute concentration differences between the blood and the interstitial fluid, fluid exits the capillaries as they pass through the body tissues. most (~90%) of this fluid returns to the capillaries over the course of their track through the body tissue, but some (~10%) is not reabsorbed. this loss of fluid would eventually cause a severe drop in blood pressure due to less overall volume in the circulatory system, and excess fluid would eventually build up and cause tissue swelling if it were not returned to the circulatory system. return of the fluid to the circulatory system is mediated by the lymphatic system. if they lymphatic system were to become blocked, then edema (swelling) would occur as a result.

Cardiac muscle fibers can contract without input from the nervous system. What does their anatomy require to create coordinated contraction? A. A lack of troponin-tropomyosin complexes B. Gap junctions to allow depolarization to spread between muscle cells C. A lack of T tubules and minimal sarcoplasmic reticulum D. More glucose

Gap junctions to allow depolarization to spread between muscle cells specialized gap junctions called intercalated discs join cardiac muscle cells to allow spread of the action potential from one cell to the next.

Where is oxygen content the LOWEST? A. In venous blood during rest B. In arterial blood during exercise C. In venous blood during exercise D. In arterial blood during rest

In venous blood during exercise Arterial blood and venous blood don't engage in oxygen/carbon dioxide exchange. all exchange occurs in capillaries. exercise causes more oxygen to be extracted from hemoglobin so venous blood during exercise has the lowest oxgyen content, after passing through capillaries in tissues with very low oxygen partial pressures, resulting in maximal offloading of oxygen from the hemoglobin into the tissues.

Blood moves throughout the body in an open circulatory system, rather slowly and under lower pressure than a closed circulatory system. This is suitable for a sedentary organism, but how do insects power flight with a comparatively slow, low-pressure open circulatory system? A. Insects use anaerobic metabolic pathways to fuel muscle movement in flight. B. Insects convert energy from the sun into metabolic energy. C. Insects use their tracheae to deliver oxygen (via air) to tissues. D. Insects have a larger muscular heart compared to most open-circ-animals.

Insects use their tracheae to deliver oxygen (via air) to tissues. C the differences between an open and closed circulatory system are that a) the circulatory fluid does not remain within the blood vessels in an open circulatory system and thus b) the circulatory fluid is also the interstitial fluid (fluid in direct contact with the body cells). additional consequences of the open circulatory system are that blood flow rates are slower and blood pressure is not as high as in a closed circulatory system, because the hemolymph moves throughout the entire body volume rather than staying enclosed within vessels. many organisms with open circulatory systems are relatively sedentary, because of these limitations of the open circulatory system (the advantage being that the open system is much less energy-demanding and thus organisms with open systems have lower metabolic demands). insects are very active and quick-moving. they overcome the limitations of the open circulatory system via the tracheae respiratory organs throughout their bodies that deliver oxygen directly to muscles and other tissues with high metabolic demands.

If a cell is placed in a 150 mM solution of NaCl, it neither shrinks nor swells. This means that the cell is ____________ with respect to the solution. A. Hypotonic B. Isotonic C. Hypertonic

Isotonic

Which of the following statements about mycorrhizae is/are FALSE? Mycorrhizae are parasitic associations of roots and fungi The fungus component in mycorrhizae benefits by receiving sugar from plants The hyphae of both arbuscular mycorrhizae and ectomycorrhizae extend into the root cortex The fungus component in mycorrhizae benefits plants by supplying water and minerals absorbed by the fungal hyphae All of the above are true statements

Mycorrhizae are parasitic associations of roots and fungi

Some plants obtain nitrogen from symbiotic fungi or bacteria.What was the original source of N for the bacteria? A. urea in the soil B. N2 gas C. carbohydrates in the soil D. lipids in the soil E. proteins in the soil

N2 gas

Which is happening when PO2 is at 100? O2 is offloading from hemoglobin into the tissues O2 is loading onto the hemoglobin in the lungs CO2 is loading onto hemoglobin in the tissues CO2 is loading onto hemoglobin in the lungs

O2 is loading onto the hemoglobin in the lungs

In closed circulatory systems, what is/are the advantage/s of a double circulatory system compared to a single circulatory system? A. There can be capillary beds in both the respiratory organ and body systems. B. Oxygenated blood can return to the heart for additional pumping before going to systemic flow. C. Oxygenated blood is kept completely separate from deoxygenated blood in the heart. D. Higher blood pressure can be sustained, supporting terrestrial lifestyles E. In double circulation, the systemic capillary beds receive oxygenated blood, whereas they do not in single circulation F. The double circulation involves contact with the respiratory organ, whereas the single does not.

Oxygenated blood can return to the heart for additional pumping before going to systemic flow. Higher blood pressure can be sustained, supporting terrestrial lifestyles

You ask to hold the baby and feel a hard mass in the abdomen. Together with your chemical and physical findings, you decide to operate on the small intestine to remove what appears to be a cyst. If you're successful, what will the baby's digestive system be able to do now that it couldn't before? Poop! Form pepsin Absorb sugars Break down fatty acids Absorb amino acids Break down carbohydrates Harbor bacteria

Poop! Absorb sugars Break down fatty acids Absorb amino acids

If a person has a pancreatic disorder, which of the following might they be unable to digest? Lipids Proteins Fats Vitamins Minerals

Proteins

Place the following steps in order for the process of carbon fixation in CAM plants. Stomata are opened at night. CO2 is released to the Calvin cycle. CO2 is fixed into a 4-carbon organic acid. Rubisco fixes CO2 during the day.

Stomata are opened at night. , CO2 is fixed into a 4-carbon organic acid. , CO2 is released to the Calvin cycle. , Rubisco fixes CO2 during the day.

Which of the following best describes the relationship between movement of water in xylem and the pressure-flow hypothesis? Increasing transpiration rates lead to proportional increases in speed of transit through phloem Root pressure generally results in greater turgor pressure in the phloem of a root than the turgor pressure in the phloem of a leaf Sugar solute moves from area of high concentration at the source to an area of lower concentration near the sink cells; water flows from xylem into phloem as a result of the high sugar solute concentration The high concentration of sugar at the source generates high turgor pressure, and loss of water via transpiration from the xylem at the sink then moves solutes through phloem None of these are true

Sugar solute moves from area of high concentration at the source to an area of lower concentration near the sink cells; water flows from xylem into phloem as a result of the high sugar solute concentration

Which of the following statements about CAM plants is/are true? The Calvin Cycle takes place deeper in the plant tissue than in C3 plants. PEP carboxylase has a higher affinity for CO2 than does rubisco. The Calvin Cycle takes place at a different time than initial CO2 fixation. The Calvin Cycle takes place at nigh

The Calvin Cycle takes place at a different time than initial CO2 fixation.

Which of the following statements about C4 plants is/are true? The Calvin Cycle takes place deeper in the plant tissue than in C3 plants. Corn (maize) is an example of a C4 plant. PEP carboxylase has a higher affinity for CO2 than does rubisco. The Calvin Cycle takes place at a different time than initial CO2 fixation. The Calvin Cycle takes place at night.

The Calvin Cycle takes place deeper in the plant tissue than in C3 plants. Corn (maize) is an example of a C4 plant. PEP carboxylase has a higher affinity for CO2 than does rubisco.

Why is it harder to breathe at high elevations? A. The air is "thicker" and more dense. B. The air is "thinner" and holds less oxygen per unit volume. C. The atmospheric pressure is higher, making it more difficult to breathe. D. The atmospheric pressure is lower, resulting in a lower partial pressure for O2.

The air is "thinner" and holds less oxygen per unit volume. The atmospheric pressure is lower, resulting in a lower partial pressure for O2.

Which of the following is not a use of a countercurrent exchange system? The exchange of CO2 and O2 in the human lung The reabsorption of salts and water in the mammalian kidney The exchange of CO2 and O2 in fish gills To flow of blood maintain temperatures in key vertebrate muscles

The exchange of CO2 and O2 in the human lung countercurrent exchangers are used in the loop of Henle in the kidney, in the capillaries/water flow in fish gills, and to maintain body temperature in arteries/veins in vertebrate limb muscles. they are not present in human lungs, which use a web-like flow of capillaries across air held in a pocket (compared to water pumped unidirectionally across fish gills) the take-home message is that countercurrent exchange is an evoltionarily common but not universal 'solution' to maximize exchange of heat/gas/ions across between two substrates.

Mom and dad come to you, their doctors, and report no dirty diapers after feedings. Their now 3-day-old baby isn't pooping, and they feel something is wrong. Which of the following reasons could possibly explain this?

There is a blockage somewhere in the baby's digestive track. The digestive enzymes in the gut are not functioning properly.

There are no valves at the point where venous blood flows into the atria. True False

True the atrioventricular valves are located between the atria and the ventricles. this valve is open as blood flows and is pumped from the atria into the ventricles. as the ventricles contract, blood is forced against the atrioventricular valves causing them to slam shut. this causes the 'lub' sound of the heartbeat.

A friend comes to you for dietary advice. Your friend is experiencing cracks and sores on the outer surface of their lips. Which of the following might be a nutrient your friend is lacking? A. Vitamin B2 B. Vitamin B9 C. Vitamin C D. Vitamin D E. Iron

Vitamin B2

A friend comes to you for dietary advice. Your friend is experiencing symptoms of anemia. Which of the following might be a nutrient your friend is lacking? A. Vitamin B2 B. Vitamin B9 C. Vitamin C D. Vitamin D E. Iron

Vitamin B9 an Iron

Rank the following nitrogenous waste products, from LEAST to MOST energetically "expensive" to produce: urea uric acid ammonia

ammonia < urea < uric acid

A. amylase 1. mouth B. bile salts 2. liver (stored in gall bladder) C. pepsin 3. stomach D. lipase, trypsin, nuclease 4. pancreas

amylase - mouth bile salts - liver (stored in gall bladder) pepsin - stomach lipase, trypsin, nuclease - pancreas

Anti-diuretic hormone (ADH) is released when plasma osmolarity increases, eventually causing a reduction in urine volume and retaining more water (thus allowing blood plasma concentration to decrease to a normal level). Which of the following are affected directly by ADH? (select all that apply) renal tubule cells in the proximal convoluted tubule renal tubule cells in the distal convoluted tubule aquaporins in tubule cells of the descending Loop of Henle aquaporins in tubule cells of the ascending Loop of Henle aquaporins in tubule cells of the collecting duct strength of the osmotic gradient in the renal medulla

aquaporins in tubule cells of the collecting duct

Which type of blood vessel has the most muscular walls? arteries veins capillaries

arteries

Plants have been subjected to strong selection for increasing access to nitrogen. List three adaptations that increase plant access to nitrogen.

association with nitrogen-fixing bacteria (legumes), assosiation with fungi (mycorrhizae), parasitism, carnivory

multiple choice question The highest possible concentration of the ultrafiltrate occurs A. in the cortex of the kidney B. in the medulla of the kidney C. in the proximal convoluted tubule D. at the entry point to the Loop of Henle E. at the apex (bend) in the Loop of Henle F. at the exit point of the Loop of Henle G. the concentration of the ultrafiltrate does not change during the process of forming urine

at the apex (bend) in the Loop of Henle

Rank the velocity of blood in each of the following types of vessels from SLOWEST to FASTEST. 1st choice veins 2nd choice arteries 3rd choice capillaries

capillaries < veins < arteries velocity is related to pressure and drag. there is extremely high pressure in arteries because of the proximity to the ventricles which have just expelled the blood from the heart. compared to capillaries, the drag is lower because the overall crossectional area is lower. thus blood moves fastest in arteries. there is very low pressure in veins, which decreases velocity compared to arteries, but there is also very little drag due to the overall low cross-sectional area in veins. thus blood moves at an intermediate speed in veins. there is an intermediate amount of pressure in capillaries but extremely high drag, as arteries are only the width of a single red blood cell. the total cross-sectional area is maximized in capillaries, which thus maximizes drag. thus blood moves slowest in capillaries. this slow movement is important to allow time for gas exchange between the capillaries and the tissues.

the roles of the cecum, rumen, and crop in digestion

contain mutualistic microbes which digest plant material; cecums are present in hindgut fermenters such as rabbits and horses; rumens are present in foregut fermenters such as cows; crops are present in birds and invertebrates

Your friend wants to apply a topical cream containing retinol to improve their skin. However, an excess of vitamin A interferes with fetal development, and your friend is currently pregnant. To be safe, which of the following foods would be good for her to eat instead of using the cream? (Hint: Use the table in your reading for help) A. dark green leafy vegetables B. Vitamin C C. dairy D. yellow-orange fruits E. green fruits F. egg yolks

dark green leafy vegetables, dairy, yellow-orange fruits

In turtles and crocodilians, what is the adaptive advantage of the bypass vessel which directs blood returning from the systemic circuit back to the systemic circuit without flowing through the lungs for gas exchange?

directs blood back to body tissues when underewater without wasting time/energy through pulmonary circut

The SA node of the heart is: enervated by the sympathetic nervous system enervated by the parasympathetic nervous system capable of depolarizing autonomously (without neural input)

enervated by the sympathetic nervous system enervated by the parasympathetic nervous system capable of depolarizing autonomously (without neural input)

Root hairs absorb nutrients from soil against the nutrient concentration gradient. Depending on the nutrient, which of the following can play a role in this process? osmosis direct diffusion facilitated diffusion electrochemical gradient co-transport

facilitated diffusion electrochemical gradient co-transport

A shift to the right of the oxygen-hemoglobin equilibrium curve correlates with: A. increased oxygen delivery to a tissue B. cooperative binding C. decreased oxygen delivery to a tissue D. noncooperative binding

increased oxygen delivery to a tissue when shifted to the right, at any particular tissue partial pressure of oxygen, hemoglobin has a lower affinity for oxygen than in the original curve. this means that hemoglobin is more likely to release oxygen to tissues under the Bohr shift (low pH)

in a legume root nodule, the nitrogenase: A. regulates the amount of oxgyen available B. is inactivated by leghemoglobin C. is absent in active bacteroids D. protects the nodule from nitrogen E. is encoded by the Rhizobium genome F. is encoded by the plant genome G. converts nitrogen gas to a biologically available form of nitrogen

is encoded by the Rhizobium genome converts nitrogen gas to a biologically available form of nitrogen

To maintain homeostasis, freshwater fish bring ions into their blood from the water. For freshwater fish, which of the following is/are true of this process? A. it occurs via simple diffusion across the cell membrane B. it occurs via facilitated diffusion through ion channels C. it occurs active transport via ATP-powered ion pumps D. it occurs primarily across the fish gill epithelial tissues E. it occurs primarily across the fish skin

it occurs active transport via ATP-powered ion pumps it occurs primarily across the fish gill epithelial tissues freshwater fish are constantly losing ions and gaining water. they must actively pump in ions from the water, because they move by diffusion down their concentration gradient out of the fish and into the water. diffusion occurs where the physical barrier to diffusion is thin. this occurs at the gills which are optimized to maximize diffusion for gas exchange. thus the gills are also susceptible to loss of ions and gain of water. this does not happen as much across the fish skin which is covered in thick scales and comparatively impermeable to water.

Which of the following organs/structures are involved in regulating kidney function via chemical signals in humans (select all that apply) kidney brain heart blood pancreas liver

kidney brain heart blood liver

Describe the role of the gizzard in digestion.

mechanical disruption of food; animals with crops lack teeth adapted for chewing the gizzard functions in mechanical breakdown in organisms that lack teeth. it is present in may different types of organisms including birds, reptiles, earthworms, some fish, and crustaceans. many types of animals swallow stones or sand that is stored in the gizzard to aid in mechanical disruption of food.

The absorption of fats differs from that of carbohydrates in that _____. A. the processing of fats does not require any digestive enzymes, whereas the processing of carbohydrates does B. most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood C. fat absorption primarily occurs in the stomach, whereas carbohydrates are absorbed from the small intestine D. carbohydrates need to be emulsified before they can be digested, whereas fats do not

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

What is an example of an animal with an open circulatory system? A. monkey B. snail C. annelid D. bird

open circulatory systems are common in invertebrates. vertebrates and some invertebrates (such as annelids and cephalopods) have closed circulatory systems. all circulatory systems have three essential components: a muscular pump (heart), a circulatory fluid (blood or hemolymph), and a series of tubes that the fluid moves through (vessels).

animals, nitrogenous wastes are produced mostly from the catabolism (breakdown) of:

proteins and nucleic acids nitrogenous wastes comes from breakdown of molecules that contain nitrogen. biological molecules containing nitrogen are primarily proteins (amino acids) and nucleic acids (nitrogenous bases)

Some plants obtain nitrogen from symbiotic fungi or bacteria. What was the original source of N that the FUNGI obtained? urea in the soil N2 gas carbohydrates in the soil lipids in the soil proteins in the soil

proteins in the soil A few species of bacteria are the only organisms capable of reducing ("fixing") atmospheric nitrogen to make it biologically available. Just as plants and other photosynthesizers are essential as a source of carbon and oxygen for most other forms of life, these bacteria are essential as a soruce of nitrogen for most other forms of life. Nitrogen is used for synthesis of nucleic acids and proteins. Fungi would use nucleid acids and proteins from the soil organic matter; they decompose organisms containgin nitrogen which was orginally made available by the nitrogen-fixing bacteria.

Plants use proton pumps, cation channels, and anion cotransporter channels to acquire nutrients from the soil. Which of the following requires a direct energy expenditure by the plant? proton pump cation channel anion cotransporter channel

proton pump plants pump protons into the soil to create a high concentration of protons outside the plant. this allows plants to use co-transporters to couple the movement of protons back into the cell (down their concentration gradient) and necessary nutrients into the cell (against their concentration gradients) via a 'coat-tail' effect. the pumping of protons out of the cell requires consumption of ATP. no energy is required by the co-transporter, as the movement of protons back into the cell down the proton concentration gradient allows movement of the nutrient in question against its concentration gradient

In the mammalian kidney the majority of water and solute recovery occurs as the ultrafiltrate passes through the proximal convoluted tubule Loop of Henle distal convoluted tubule collecting duct ureter

proximal convoluted tubule

in a legume root nodule, the leghemoglobin: regulates the amount of oxgyen available is inactivated by nitrogenase is absent in active bacteroids protects the nodule from nitrogen is encoded by the Rhizobium genome is encoded by the plant genome converts nitrogen gas to a biologically available form of nitrogen

regulates the amount of oxgyen available is encoded by the plant genome

Iron deficiency is often indicated by yellowing in newly formed leaves. This suggests that iron is _____. concentrated in the xylem of older leaves relatively immobile nutrient in plants concentrated in the phloem of older leaves found in leghemoglobin and reduces the amount available to new plant parts tied up in formed chlorophyll molecules

relatively immobile nutrient in plants any immobile nutrient (present in a structure which cannot be broken down) in limiting supply is stuck in the old leaf and cannot be moved to the new leaves; new leave suffer for lack of immobile nutrients when those nutrients are in short supply.

fetal hemoglobin (encoded by a different gene than adult hemoglobin) has a higher affinity for oxygen than maternal hemoglobin. Draw this curve on the graph below, where the existing line represents the binding curve for maternal hemoglobin.

shifts to the left

Draw what happens to the hemoglobin-saturation curve when pH is decreased compared to the "normal" curve.

shifts to the right

Which of the following would you expect to have the greatest surface area, and why? mouth; stomach; small intestine; large intesting

small intestine; where bulk of nutrient absorption occurs

Sodium is not an essential nutrient for plants, but is essential for animals. Given what you know from previous modules, why is this the case?

sodium is required for generating action potentials in the nervous system; plants don't have nervous systems

According to the pressure-flow hypothesis of phloem transport: solute moves from area of high concentration to an area of lower concentration near the sink cells the combination of a high turgor pressure in the source and transpiration water loss from the sink moves solutes through phloem conduits water is actively transported into the source region of the phloem to create the turgor pressure needed the pressure in the phloem of a root is normally greater than the pressure in the phloem of a leaf none of these

solute moves from area of high concentration to an area of lower concentration near the sink cells

Phloem transport of sucrose is often described as going from source to sink. Which of the following is most likely to function as a source? growing root in late summer storage bulb in early spring growing leaf in early spring shoot tip in late fall

storage bulb in early spring

"Germ-free" laboratory mice birthed and reared in completely sterile environments (this is difficult but possible!) have higher nutritional needs compared to normal mice. Explain why.

symbiotic gut bacteria aid in digestion by breaking down molecules the host cannot digest and making them available to the host

Certain nutrients are considered "essential" in the diets of some animals because _____. A. the nutrients are required for normal organismal function B. only certain foods contain them C. these animals are not able to synthesize these nutrients D. only those animals use those nutrients

the nutrients are required for normal organismal function these animals are not able to synthesize these nutrients

Which of the following is/are true of the pulmonary circuit in a four-chambered, double circulation system? A. the pulmonary circuit pumps oxygen-poor blood into the lungs B. the pulmonary circuit pumps oxygen-rich blood into the body C. blood is pumped through the pulmonary circuit by the left side of the heart D. blood is pumped through the pulmonary circuit by the right side of the heart E. the blood in the pulmonary artery is depleted of oxygen

the pulmonary circuit pumps oxygen-poor blood into the lungs blood is pumped through the pulmonary circuit by the right side of the heart the blood in the pulmonary artery is depleted of oxygen

The only animals that use skin as a significant portion of their respiratory surface (ie, use skin for gas exchange) are largely aquatic/amphibious. Yet water is a less efficient medium for gas exchange than air. Why do you suppose all skin-ventilated animals reside in/near water? A. having a lot of skin surface area exposes you to greater changes in temperature and other environmenal risks B. the thin membranes required for efficient gas exchange increases the risk of dehydration C. natural selection has increased the efficiency of gas exchange in aquatic animals compared to terrestrial animals D. it is an evolutionary 'accident' based on lack of common ancestry between aquatic and terrestrial vertebrates

the thin membranes required for efficient gas exchange increases the risk of dehydration

Nitrifying bacteria can have a strong impact on the nutrient content of soils because:

they transform biologically available N to a form that that washes out of soil easily

What is the function of proton pumps localized in the plant plasma membrane? A. to provide channels for ion diffusion B. to transfer phosphorus groups from ATP to proteins C. to transfer metal ions across the plasma membrane D. to transfer anions across the plasma membrane E. to create a membrane potential

to create a membrane potential

Rank the blood pressure in each of the following types of vessels from LOWEST to HIGHEST. veins arteries capillaries

veins < capillaries < arteries pressure is related to speed, volume, and vessel diameter. there is extremely high pressure in arteries because of the proximity to the ventricles which have just expelled the blood from the heart. there is also a high volume of blood contained in the arteries, which tend to have an intermediate diameter compared to veins (wider) and capillaries (much narrower). there is an intermediate amount of pressure in capillaries, which have very narrow diameters, but massive cross-sectional area and extremely slow movement of blood. there is very low pressure in veins, where blood is moving more slowly and is contained in vessels that are typically wider than arteries