Describe ways in which the bodies of complex animals are structured for exchanging materials with the environment. Do all animals share such features?

Compared with a smaller cell, a larger cell of the same shape hasa. less surface area.b. less surface area per unit of volume.c. the same surface-area-to-volume ratio.d. a smaller cytoplasm-to-nucleus ratio.

Negative-feedback mechanisms are a. most often involved in maintaining homeostasis. b. analogous to a furnace that produces heat. c. found only in birds and mammals. d. all of the above

An animal's inputs of energy and materials would exceed its outputsa. if the animal is an endotherm, which must always take in more energy because of its high metabolic rate.b. if it is actively foraging for food.c. if it is growing and increasing its mass.d. never; due to homeostasis, these energy and material budgets always balance.

Which of the following cell structures would you expect to be most important in the growth of bacteria on the surface of your teeth?a. cell wallb. fimbriaec. flagellad. cilia

Which of the following animals uses the largest percentage of its energy budget for homeostatic regulation?a. marine jelly (an invertebrate)b. snake in a temperate forestc. desert insectd. desert bird

DRAW IT Draw a model of the control circuit(s) required for driving an automobile at a fairly constant speed over a hilly road. Indicate each feature that represents a sensor, stimulus, or response.

The eukaryotic cytoskeleton is a highly dynamic network of filaments and motor proteins. Which of the following correctly describe activities of these cytoskeletal components? Select True or False for each statement.T/FMyosin motors walk toward the plus ends of intermediate filaments.T/FDynein motors are responsible for the whip-like movement of eukaryotic flagella.T/FKinesin motors move vesicles along tracks toward the microtubule-organizing center.T/FActin filaments are required for cytoplasmic streaming.