When the human body is responding to stress, the hormone adrenaline is released. A short time later, the body returns to normal. This is an example of how a human*

Like humans, animals including dogs and cats get goose bumps. On a cold day, these goose bumps cause their coats to expand creating a layer of insulation. If the animal is scared, the coat will also expand making the animal look larger to predators. These responses serve as examples of*

Which change is an example of a response to a stimulus?*

A small lizard spends the morning hours lying in the sunlight until its body temperature rises. Later on in the day, the lizard rests in a shady area until its body temperature cools. This type of behavior is important to*

The diagram below represents changes that take place within the human body.

The diagram represents*

The diagram below represents an activity that occurs in the human body.

This diagram best illustrates*

Riding a bicycle requires balance and constant adjustment and monitoring by the rider in order to continue cycling. Successfully riding a bicycle most directly results from the ability to*

When an ant in a colony dies, the live ants will throw the dead ant out of the anthill. If a live ant from the colony, ant X, is sprayed with a chemi- cal characteristic of dead ants, the live ants will repeatedly throw this ant out of the anthill until they can no longer detect the chemical on ant X. What is the best explanation for this behavior?*

One half-hour after the liter of water was consumed, the urine produced by the kidneys was*

Breathing rate is constantly being monitored and adjusted in the human body, which results in*

A substance directly involved in cellular commun- ication within the human body is*

The graph below shows changes in the level of glucose in the blood of a person over a period of time.

The graph represents the*

A person usually experiences small variations in body temperature over a 24-hour period. These variations in temperature are an example of*

Feedback mechanisms have evolved that maintain homeostasis. Describe how homeostasis is maintained through feedback. In your answer, be sure to:

• identify one feedback mechanism in the human body [1]

• identify, other than death, one specific result if homeostasis fails in the human body [1]

• describe how a plant regulates water loss through a feedback mechanism that involves guard cells [1]*

More middle- and long-distance runners have tested positive for blood doping than short-distance runners, such as sprinters. State one reason why athletes participating in certain events might be more likely to practice blood doping than others. [1]*