Mastering Biology - WEEK 10

Assume there are 200 MendAliens living on an island in my back yard. If my island has an area of 20 hectares, what is the population density of MendAliens in terms of MendAliens per hectare?

10 MendAliens per hectare. Population density is calculated as population size divided by area: 200 MendAliens / 20 hectares = 10 MendAliens per hectare.

A population is growing exponentially and its instantaneous growth rate (r) is 0.02. Would the number of individuals added to the population (rN) be greatest at a population size (N) of 20, 500 or 1000? See Section 51.3 (Page) .

1000

Suppose researchers marked 800 turtles and later were able to trap a total of 300 individuals in that population, of which 150 were marked. What is the estimate for total population size?

1600

You are doing a mark-recapture experiment to determine the population size of the MendAliens living on an island in my back yard. Initially, you catch and mark 130 MendAliens, which you then release. Next, you capture 90 MendAliens, of which 20 are marked. What is your estimate of the population size of MendAliens living on the island in my back yard?

585

Estimate total population size in a mark-recapture study in which 200 individuals were initially marked, and you recaptured 150 of which 50 were marked. See Section 51.1 (Page) .

600

Which of the following statements describes a negative feedback response?

After a meal, blood sugar levels in the body rise; insulin is secreted to lower blood sugar levels.

Which of the following actions is not a function of the epithelium?

Allows the internal environment to alter its conditions to match those of the external environment. The epithelium allows the internal environment to remain constant even if the external environment changes

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

Both endotherms and ectotherms exchange heat with the environment through convection, conduction, radiation, and evaporation.

Why do populations grow more slowly as they approach their carrying capacity?

Density-dependent factors lead to fewer births and increased mortality.

Which two terms apply to most mammals?

Endotherm and homeotherm

Which of these physical processes does not help a lizard increase its body temperature?

Evaporation. When water evaporates from a lizard's skin to become a gas, heat is pulled from the body of the lizard. However, evaporation cannot result in heat gain.

A population is correctly defined as having which of the following characteristics?I. inhabiting the same general areaII. belonging to the same speciesIII. possessing a constant and uniform density and dispersion

I and II only

Which component of a homeostatic system compares sensory information to a target value?

Integrator. An integrator sends instructions to an effector based on sensory information.

Looking at the data in the accompanying figure, what can be said about survival and clutch size?

Large clutch size correlates with low survival.

Which of the following is the most important assumption for the mark-recapture method to estimate the size of wildlife populations?

Marked individuals have the same probability of being recaptured as unmarked individuals during the recapture phase.

In mammals such as a dog, thermoregulation is monitored by temperature receptors located through the body. If a mammal is cold, which of these responses would not help raise its temperature back to normal?

Panting. Rapid panting increases evaporative cooling on the moist surfaces of the lungs, mouth, and extended tongue. This provides cooling of the body by removing heat from the blood circulating near these surfaces

You observe a lizard sitting on a log on a sunny day. If the lizard is attempting to raise its body temperature by basking in the Sun, what mechanism of heat transfer is being employed?

Radiation

Which term describes a steady state in which the internal conditions of an organism are kept within a narrow range without regard to the external conditions?

Regulatory homeostasis. Regulatory homeostasis involves adjusting the internal conditions of an organism to stay within a narrow range without regard to the external conditions.

Which component of a homeostatic system perceives changes in some parameter of the environment?

Sensor. A sensor perceives changes in some parameter of the environment.

Which of the following actions acts to warm a homeothermic body?

Shivering. Shivering generates metabolic heat and warms the body.

Suppose you trap some fish in a lake, mark them, and release them. Every month for a year you re-trap a similar number of the fish and release them. You notice each month that the proportion of marked fish trapped is declining. Which of the following is a reasonable explanation for this observation? See Section 51.2 (Page) .

The fish do not have long lifespans so some of the marked fish are dying each month.

As N approaches K for a certain population, which of the following is predicted by the logistic equation?

The growth rate will approach zero.

Why can't a female lizard have both high fecundity and high survival?

The more energy the female devotes to offspring, the less that can be devoted to her survival

True or false? Organisms must maintain homeostasis because optimal enzyme activity is achieved within a very narrow range of conditions.

True. Enzyme activity depends on conditions within a cell, such as temperature and pH, which must be kept within a certain narrow range.

What is the main reason that a person sitting on the beach with an air temperature of 15°C loses heat less rapidly than when immersed in lake water at 15°C?

Water conducts heat more efficiently than air does.

Which of the following is an example of negative feedback?

When blood glucose concentration increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases.

Abiotic factors

cold temperatures to the north, occurrence of deep seawater (Atlantic Ocean and Gulf of Mexico) surrounding southern Florida

Biotic factors

competition for food, increased predation on eggs or juveniles, occurrence of parasites, spread of disease

An ecologist recorded 12 white-tailed deer, Odocoileus virginianus, per square kilometer in one woodlot and 20 per square kilometer in another woodlot. What was the ecologist comparing?

density

Compared to ectotherms, endothermic animals are likely to be at the greatest disadvantage in ________.

environments with variable and limited food sources

Panting by an overheated dog achieves cooling by ________.

evaporation

Burmese pythons were first found in the wetlands of Everglades National Park in the 1980s, but only rarely. The graph shows what happened next. Most of the data are derived from chance encounters of pythons on roads (pythons are notoriously difficult to find). How would you describe the type of population growth in pythons from 2000 to 2008?

exponential

An animal's inputs of energy and materials would exceed its outputs if _____.

it is growing and increasing its mass

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

poikilothermic

A woman standing and watching the stars on a cool, calm night will lose most of her body heat by _____.

radiation

The mark-recapture method would be best for sampling a population of

sharks

Which of the following would increase the rate of heat exchange between an animal and its environment?

wind blowing across the body surface