Which of the following have a four-chambered heart?
Birds
Certain Nutrients are considered "essential" in the diets of some animals because
These animals are not able to synthesis these nutrients
Organisms with circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have a?
Closed circulatory system
In the digestive system, peristalsis is?
Smooth muscle contractions that move food along the esophagus
Carbon Dioxide levels in the blood and cerebrospinal fluid affect its pH. This enables the organism to sense a disturbance in the gas levels as...?
The medulla oblongata, which is in contact with the cerebrospinal fluid, monitors pH and uses this measure to control breathing.
PKU (phenylketonuria) is a hereditary condition, in which infants and young children who ingest the amino acid phenylalanine risk serious neurological damage. However, the risk of damage can be substantially reduced by the severe restriction of phenylalanine in the diet. Which of the following in the nutritional concept that forms the basis for this preventative treatment?
Essential Nutrients
Hypoglycemia, or low levels of glucose in the blood of a healthy human, is 'corrected" by a(n)
Increase in secretion of glucagon
In a cold and yet survivable environment, an ectoderm is more likely to survive an extended period of food deprivation than would an equally sized endotherm because ectoderms
invest little energy in temperature regulation
After surgical removal of an infected gallbladder, a person must be especially careful to restrict his or her dietary intake of?
Fat
Coutercurrent exchange in the fish gill helps to maximize
diffusion
The bile salts function in fat digestion by?
dispersing big droplets of fats to small droplets
The only vertebrates in which the blood flows directly from respiratory organs to body tissues without first returning to the heart are?
Fishes
The body's automatic tendency to maintain a constant internal environment is termed
homeostasis
Human red blood cells 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 the back to the left ventricle, this red blood cell must pass through?
two capillary beds
An example of a properly functioning homeostatic control system is seen when?
The kidneys excrete salt into the urine when dietary salt levels rise
Without functioning parietal cells an individual would
not be able to initiate protein digestion in the stomach
The most important chemical stimuli leading to increased rate and depth of breathing is?
concentration of CO2 in the blood
Which common event most closely resembles negative feedback?
The furnace turns off when the temperature in the room reaches the set point
After ingestion, the first type of macromolecule to be enzymatically attacked in the human digestive system is?
Carbohydrates
In the circulatory system of humans, how is most of the carbon dioxide transported?
Bicarbonate ions in the plasma
Stomach acid
activates pepsinogen into pepsin
Which of the following organs is incorrectly paired with its function?
Large intestine and bile production
An example of a connective tissue is the
Blood
An advantage of a complete digestive system over a gastrovascular cavity is that the complete system
allows specialized functions in specialized regions
An increase in pH 7.2 to pH 7.4 around hemoglobin causes
an increase in the affinity of hemoglobin to bind to oxygen molecules
Increased levels of glucose levels in blood after a meal may trigger
insulin release from the pancreas
Use the figure above to answer this question. When does contraction of the atria begin?
immediately after the P-wave
Digestive secretions with a pH of 2 are characteristic of the?
stomach
Air rushes into the lungs of humans during inhalation because
the rib muscles and diaphragm are contracted, increasing the lung volume
Three types of cells which are present in the gastric glands are responsible for some secretion of gastric juice. ____ cells secrete pepsinogen (an inactive form of digestive enzyme pepsin). _____ cells lubricate and protect the cells lining in the stomach. ____ cells secrete HCl
chief, mucus, parietal
Which of the following explains the reason that the velocity of blood blow is the lowest in capillaries?
The total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries of any other part of the circulatory system
The bile salts
emulsify fats in the duodenum
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 in epithelial cells
Why is gas exchange more difficult for aquatic animals with gild than for terrestrial animals with lungs?
water contains much less O2 than air per unit volume
A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why?
the partial pressure of O2 in the air at high elevations is lower than at sea level
Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to?
be unaffected
The Bohr shift on the oxygen-hemoglobin dissociation curve (see figure 1 below) is produced by changes in?
pH
which of the following organisms breathe through tracheae?
insects
Agents that help emulsify fats are produced by?
9
What structures are involved in the digestion of carbohydrates?
1 and 4
the thin horizontal arrows in the figure show that?
The warmer arterial blood transfers hear to the cooler venous blood
What percentage of individuals in the study group had an LDL level below 100 mg/dL?
about 58%
what percentage of individuals in the control group had an LDL level below 100 mg/dL?
17%
Based on these two histograms what conclusion can you draw?
On average, individuals with an inactivating mutation in the PCSK9 gene have lower plasma LDL levels than wild type individuals
How would you compare the risk of cardiovascular disease between the study group and the control group?
the study group has a lower risk than the control group
what is the best explanation for the fact that the two histograms overlap as much as they do?
many factors in addition to PCSK9 enzyme activity affect plasma LDL levels
Now consider two individuals with a plasma LDL level of 160 Mg/dL, one from the study group and one from the control group. What do you predict regarding their relative risk for cardiovascular disease?
the risk is equal because their LDL levels are the same
The direction of blood flow in the fish gills is opposite the direction of eater flow past the gills. Which of the following should be expected if the structural relationship represents a countercurrent exchange mechanism for O2?
A net movement of oxygen from water into blood occurs along the entire distance where blood and water are in close contact
What percentage of the mouse's energy budget goes to basal metabolism?
about 25%
without considering the sizes of wedges, how do three pie charts differ in which function they include?
unlike the penguin and the mouse charts the python chart included growth but does not include thermoregulation