Mastering Biology Chapter 40

Generally, epithelial cell layers are responsible for separating two fluids. For example, the epithelium of blood vessels in animals separates the blood from the interstitial fluid. What characteristic would you expect to see in an epithelium that was specialized for passive diffusion of materials from one fluid to another?

A single layer of flattened cells

Bone consists of

a mixture of hardened collagen and minerals

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

adipose tissue

Most land-dwelling invertebrates and all of the amphibians

are ectothermic organisms with variable body temperatures

Most types of communication between cells utilize

chemical or electrical signals

The concurrent arrangement of blood vessels is an adaptation that allows the goose to

conserve heat in its core when the goose is swimming in cold water

Consider the energy budgets for a human, an elephant, a penguin, a mouse, and a snake. The ________ would have the highest total annual energy expenditure, and the ________ would have the highest energy expenditure per unit mass.

elephant:mouse

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

epithelial tissue

Most of the exchange surfaces of multicellular animals are lined with

epithelial tissues

Independent of whether an organism is an endotherm or ectoderm, the least reliable indicator of an animal's metabolic rate is the amount of

food eaten in one day

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

hemeostasis

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

hypothalamus

All types of muscle tissue have

interactions between actin and myosin

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

All animals, whether large or small, have

most of their cells in contact with an aqueous medium

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

The metamorphasis of a tadpole to an adult frog involves a thorough reconstruction of the animal's body. All of the structural and physiological changes must be complete or the frog will not survive the transformation. Which type of regulation would ensure that the animal completed its transformation?

positive feedback

Connective tissues typically have

relatively few cells and a large amount of extracellular matrix

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

smooth muscle

Muscle cells are organized to perform specific types of contractions within a tissue. Which of the following is a characteristic of smooth muscle?

spindle-shaped cells with a single nucleus

Cardiac muscle cells are both

striated and interconnected by intercalated disks

The metabolic rate of an animal is most accurately determined by

the amount of energy used by an animal in a given time

Hummingbirds are small birds that require a regular food supply. When hummingbirds are faced with a situation that decreases their food supply, such as a storm, which of the following adaptations would be most useful for the bird to survive such an unpredictable and short-term absence of food resources?

torpor

Both the endocrine and nervous systems transmit information around an animal's body. Which of the following is a characteristic of nervous system signals?

travel quickly, allowing rapid transmission of signals

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