Living Environment Fall Semester Midterm Review

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

The diagram represents...?

• cellular differentiation

• dynamic equilibrium

• biological evolution

• gene interaction

2. In humans, what happens when the breathing rate increases?

• 1. Additional carbon dioxide will diffuse into the blood as oxygen diffuses out of the blood in the lungs.

• 1. Oxygen from body cells will diffuse more rapidly into red blood cells.

• 1. Additional oxygen will diffuse into the blood as carbon dioxide diffuses out of the blood in the lungs.

• 1. Increased oxygen dissolved in the blood will stimulate the cerebrum to slow the breathing rate.

2. Which line in the graph below best illustrates an effect of the carbon dioxide level in the blood on breathing rate before, during, and after a period of exercise?

• A

• B

• C

• D

What is the main function of gas exchange?

• 1. To remove carbon dioxide and supply oxygen to the body

• 1. To remove oxygen from the body

• 1. To supply carbon dioxide and remove

     oxygen from the body

• 1. To supply water to the body cells

It may be harmful when people compete to see who can hold their breath the longest underwater.

Without oxygen, brain cells...?

• cannot make enough ATP

• have too few mitochondria

• make too many enzymes

• have too much water

An increase in breathing rate can be triggered by an increase in the...?

• carbon dioxide content of the blood

• oxygen content of the atmosphere

• number of platelets in the blood

• number of red blood cells

7. Feedback mechanisms are best described as processes that help...?

• 1. reduce hormone levels to below normal in the blood

• 1. destroy hormones in the blood

• 1. directly control muscle contraction in the

     leg

• 1. keep body conditions near a normal, steady state

7. Some pituitary hormones cause the ovaries to secrete hormones. These ovarian hormones then influence the production of the pituitary hormones.

9. This type of control mechanism is known as...?

• 0. ovulation

• 0. negative feedback

• 0. gametogenesis

• 0. a menstrual cycle

Blood sugar levels increase after a meal and eventually return to normal. This is represented in the diagram below. This constant correcting of blood sugar levels within the body is accomplished by...?

• a feedback mechanism

• an immune response

• an allergic reaction

• manipulating a gene

11. The diagram below shows the interaction between blood sugar levels and pancreatic activity.

1. This process is an example of...?

• 1. a feedback mechanism maintaining homeostasis

• 1. an immune system responding to prevent disease

• 1. the digestion of sugar by insulin

• 1. the hormonal regulation of gamete

     production