CH 40

if you monitored energy allocation in the penguin, the growth category might now be a significant part of the pie chart, even though adult penguins don't change in size from year to year. What limitation in such energy budget studies does this lead you to consider

although penguins don't grow as adults, they increase and decrease in size as they repeatedly form and use energy stores. a significant amount of energy might be stored in fat during part of the year but be missing from the pie chart because it is used later in the year

under what temperature conditions would it benefit the jackrabbit to flatten its ears against its body

by flattening its ears long its body when temperatures are high, the bunny can reduce the total surface area fo tis body therefore the amount of heat absorbed

suppose you design a lab using a few objects as landmarks. how migh you position

certainty of paternity is higher with external fertilization

how is mirgration based on circannual rhythms poorly suited for adaptation to global climate change

circannual rythms are based on the cycles of light and dark in the environment. There might be a selecion for predators attracted to the alarm substance because they would be more likely to encounter crippled prety than predators incapable of responding. Fish with adequate defenses might show no change because they have a selective advantage if they do not waste energy responding to the alarm substance

what are the properties shared by all types of epithelia?

epithelial cells line a surface, are tightly packed, are situated on top of a basal lamina, and form an active and protective interface with the external environment

how might associative learning explain why unrelated distasteful or stinging insects have similar colors?

forgetting the location of some caches, which consist of pine seeds buried in the ground, might benefit the nutcracker by increasing the number of pines growing.

describe the difference between negative feedback and positive feedback

in negative feedback, a change triggers control mechanisms that counteract further change in that direction. in positive feedback, a change triggers mechanisms that amplify the change

if an egg rolls out of a neset, a mother goose will retreive it by nudging it with her beak and head. If researchers remove the egg or substitute a ball during this process, the goose continues to bob her beak and head while she move back to the nest. what type of behavior is this? suggest a proximate and ultimate explanation

it an example of a fixed action pattern. the explanation might be that nudging and rolling are released by the sign stimulus of an object outside the nest, and behavior is carried to completion once initiated. the ultimate explanation might be ensuring eggs remain int he nest increases the chance of producing healthy offspring

suppose you exposed various fish to the alarm substance from minnows. Suggest why some might respond like the minnows and why some might show increase in activity and other might show no change

natural selection would tend to favor convergence in color pattern because the predator learned to associate pattern with a sting or bad taste and would avoid all others with that same pattern

is it accurate to define homeostasis as a constant internal environment

no, even though an animal regulates some aspects of its internal environment, the internal environment fluctuates slightly around set points. Homeostasis is a dynamic state

which animal must eat a larger portion of its weight in food each day? a house car or an african lion caged in a zoo

the house cat; the smaller the animal, the higher its metabolic rate and its demand for food per unit of body mass

flowers differ in how much sunlight they relfect. Why might this matter to a hummingbird seeking nectar on a cool morning

the hummingbird (endoderm) has a very high metabolic rate. If by absorbing sunlight certain flowers warm their nectar, a hummingbird feeding on these flowers is saved the metabolic expense of warming the nectar to its body temperature

suppose at the end of a hard run on a hot day you findn that there are no drinks left in the cooler. If, desparate, you dunkn your head into the cooler at which your body temperature returns to normal

the ice water would cool tissues in your head, including blood that would then circulate throughout the body. This effect would accelerate the return to a normal body temperature. However, if it reached the eardrum and cooled the hypothalamic thermostat, the perceived drop in temperature would inhibit sweating and blood vessels dilation, slowing cooling in the body

if a mouse and a small lizard of the same mass were placed in exerimental chambers under identical environmental conditions which animal could consume O2 at a higher rate?

the mouse would consume O2 at a higher rate because it is an endotherm and therefore its basal metabolic rate is higher than the ectothermic lizard's standard metabolic rate

what mode of heat exchange is involved in "wind chill", when air feels colder than still air at the same question

wind chill involves heat loss through convection

clark's nutcrackers hide tens of thousands of seeds each falls, some of which they never retrieve. why might there be an evolutionary advantage for the species if individuals forgot the location of some caches?

you might move objects around to establish an abstract rule, while maintaining a minimum of fixed metric relationships, that is, avoiding having the food directly adjacent to or a set distance from a landmark

suppose you are standing at thee dge of a cliff and you suddenly slip - you barely manage to keep your balance to keep from falling. As your heart races, you feel a burst of energy, due in part to a surge of blood into dilated vessels in your muscles and an upward spike in the level of glucose in your blood. Why might you expect that this "fight or flight" response requires both the nervous and endocrine system

you need the nervous system to perceive the danger and provoke a split-second muscular response to keep from falling. The NS does not make a direct connection with blood vessels or liver cells. Therefore, instead of a hormone (adrenaline) being released by the endocrine system, the NS can bring about change in just a few seconds

if you were deciding where to locate the thermostat in a house, what considerations would govern your decision? how do these factors relate to the location of many homeostatic control sensors in the human brain?

you would want to locate a thermostat close to where you would be spending time, right in the path of the output heating system. Similarly, the sensors for homeostasis located in the human brain are separated from environmental influences and can monitor conditions in a vital and sensitive tissue