1. Insects because their open circulatory system often requires less energy to move blood throughout the body than a closed circulatory system.Insects would be favored because an open circulatory system stores energy.
2. Birds because their closed circulatory system stores energy better than an open circulatory system.
3. Insects because their closed circulatory system often requires less energy to move blood throughout the body than a closed circulatory system.
4. Birds because their open circulatory system is more efficient at delivering nutrients than a closed circulatory system.

1. Because an elongated heart allows blood to easily reach all the parts of the body from the heart.
2. Because the elongated heart allows more blood to reach all the parts of the body, it allows for more nutrient exchange.
3. Because an elongated heart allows blood to easily return to the heart from a few points within the body cavity.
4. Because an elongated heart allows blood to easily return to the heart from most points within the body cavity.

1. The open circulatory system of birds warms their entire body quicker, allowing them to live in colder climates more successfully than insects.
2. The closed circulatory system allows blood flow to increase to the flight muscles during flight, allowing insects to be better fliers than birds.
3. The greater efficiency of a closed circulatory system allowed birds to become larger than insects.
4. The simplicity of the open circulatory system allows insects to have a higher metabolism than birds.

Serum is used to diagnose and monitor diseases, and it is also used to classify blood types. Which of the following statements best describes serum?

1. It is a liquid consisting of 90 percent water and has coagulation factors.
2. It is plasma without the coagulation factors.
3. Serum is only made of albumin.
4. Serum is the same substance as interstitial fluid.

1. Blood types are distinguished on the basis of the presence or absence of different metals found on the surface of red blood cells.
2. Blood types are distinguished on the basis of the presence or absence of different proteins found inside the red blood cells.
3. Blood types are distinguished on the basis of the presence or absence of different lipids found inside the red blood cells.
4. Blood types are distinguished based on the presence or absence of different antigens found on the surface of the red blood cells.

The inflammatory response involves increasing blood flow to areas of the body that contain immune system cells fighting a pathogen or foreign object. The inflammatory response is an example of a positive feedback loop. Based on this, what would cause the inflammatory response to stop in a certain area of the body?

1. The white blood cells destroy all of the pathogens and foreign objects.
2. The white blood cells disperse away from the site.
3. More white blood cells arrive to fight the pathogens and foreign objects.
4. Fewer white blood cells are needed to finish fighting the infection.

________ is the phase of the cardiac cycle where the heart contracts, which pushes out the blood and pumps it around the body.

1. Diastole
2. Cardiac output
3. Myocardial infarction
4. Systole

1. endocardium
2. electrocardiogram (ECG)
3. peripheral resistance
4. cardiac output

1. Part B would allow vasodilation in the blood vessel if the blood vessel brings blood to relatively inactive cells, such as fat cells.
2. Part C would allow vasodilation in the blood vessel if the heart and body’s metabolism slow.
3. Part B would allow vasodilation in the blood vessel if the blood vessel takes blood away from an active organ system.
4. Part C would allow vasodilation in the blood vessel if the blood vessel takes blood to a muscle cell that is contracting quickly.

1. The tunica externa prevents blood cell adhesion to the wall of the vessel. It is thicker in the artery to protect against the higher blood pressure found in arteries.
2. The tunica externa protects the vessel from wear and tear and also provides support for the vessel. It is thicker in the artery to protect against the higher blood pressure found in arteries.
3. The tunica externa protects the vessel from wear and tear and provides support for the vessel. It is thicker in the artery to protect against the lower blood pressure found in arteries.
4. The tunica externa prevents blood cell adhesion to the wall of the vessel. It is thicker in the artery to protect against the lower blood pressure found in arteries.