Exam 39: Animal Form and Function

Which of the following is an example of negative feedback?

A moth preparing for flight on a cold morning may warm its flight muscles via ________.

-The thin horizontal arrows in the accompanying figure show that the ________.

The crucian carp (Carassius carassius) is a Northern European freshwater fish often inhabiting ponds that become hypoxic (have reduced oxygen levels) and even anoxic (have no oxygen) when the surface freezes during the winter. Surprisingly, when oxygen levels are normal, these fish lack the lamellae that provide a large surface area for gas exchange between water and blood: their gills are smooth. Yet when the level of oxygen in the water falls, the gill morphology undergoes a change: packing cells stop dividing and programmed cell death is induced, exposing gill lamellae that were buried in other tissue. With lamellae exposed, the gills have increased surface area for gas exchange. These changes in gill lamellar profile are reversible: investigators observed that the gills return to their normal structure within seven days after returning the fish to well-oxygenated water. (Jørund Sollid, Paula De Angelis, Kristian Gundersen, and Göran E. Nilsson. 2003. Hypoxia induces adaptive and reversible gross morphological changes in crucian carp gills. Journal of Experimental Biology 206:3667-73.) Refer to the paragraph on crucian carp. Gills serve multiple functions in fish in addition to gas exchange. Given the large surface area of gills with lamellae, what is the most likely explanation for why crucian carp cover protruding lamellae in their gills when levels of oxygen are normal?

Which of the following statements comparing endotherms and ectotherms is correct?

A behavioral physiologist is studying the homeostatic control of blood pH. In a trial, a lizard runs on a treadmill for a set amount of time and the blood pH is measured. The blood pH drops as carbon dioxide is released into the bloodstream. Which component of the homeostatic feedback system is responsible for determining if the blood pH is far enough from normal that a response is necessary?

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

The composition of connective tissue determines its physical properties. If you gently bend your ear, and then let go, the shape of your ear will return. This can best be explained by the presence of what tissue type in your ear?

Most mammals are strict homeotherms. Elephants allow their body temperature to vary during the hottest parts of the day, meaning they are ________.

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 ________.

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?

An elephant and a mouse are running in full sunlight, and both overheat by the same amount above their normal body temperatures. When they move into the shade and rest, which animal will cool down faster?

Connective tissues typically have ________.

In house sparrows (Passer domesticus) it is generally found that both males and females care for the eggs and young. However, some male house sparrows do not provide parental care. In addition, it is known that young that receive parental care from both the male and female are more likely to survive to fledging (leaving the nest). Which of the following activities by males that do not provide parental care would represent the most beneficial trade-off for the reduced survival of their offspring?

Compared with a smaller cell, a larger cell of the same shape has ________.

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?

A researcher is setting up an experiment to measure basal metabolic rate in prairie voles (Microtus ochrogaster-a small rodent). Which of the following would be the best set of conditions for the voles immediately before and during the measurement?

Which of the following structural features of epithelial tissues are related to the function of these cells? Epithelial cells ________.

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?

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