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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?*
Base your answers to questions 9 on the information and graph below and on your knowledge of biology.
An investigation was carried out to determine the effect of drinking an excessive amount of water on urine flow. A subject drank 1 liter of water in 5 minutes, and then urine output was measured. The graph shows how the human adult kidneys responded to regulate water balance in the body. Urine output was measured every 10 minutes for a little over 3 hours. Normal output for an average adult is approximately 0.5–1 mL/min.
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*
Base your answer to question 14-16 on the information below and on your knowledge of biology.
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 
• identify, other than death, one specific result if homeostasis fails in the human body 
• describe how a plant regulates water loss through a feedback mechanism that involves guard cells *
Base your answers to questions 17 on the information and diagram below and on your knowledge of biology.
Blood is a fluid tissue, which means that blood cells are suspended in a fluid called plasma. Blood tests are concerned with not only the number of blood cells present, but with the amount of plasma that surrounds the cells.
The diagram below represents tubes containing blood samples from an athlete before and after blood doping. Blood doping is an illegal practice reportedly used by some athletes a few weeks before an athletic event, and involves removing whole blood from an athlete, separating the oxygen-carrying red blood cells (RBCs), and then freezing them. These RBCs are thawed and returned to the athlete’s body just before the athlete competes. Serious health risks are associated with this practice.
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. *