Download Homeostasis Keystone Questions of the Day Key

Name_______________________
Period_______________________
Date_______________________
Homeostasis and Transport
Keystone Questions of the Day, Day 1
1.
The fluid mosaic model shown above describes the structure and function of
A. nuclei.
B. chromosomes.
C. chloroplasts.
D. cell membranes.
2. Cells can function
A.
B.
C.
D.
in rapidly changing temperatures and pHs.
at any temperature and pH.
in a wide range of pHs and temperatures.
only in a narrow range of temperature and pH.
3. Examine the following diagrams of plant cells. Each cell has been placed in a different
solution.
1
2
3
The cell in diagram 1 has been placed in a solution that contains _______ the interior of
the cell.
A. the same concentration of water as
B. a higher concentration of water than
C. water that is warmer than
D. water that is cooler than
4. All cells have a protective barrier that is formed of proteins and a lipid bilayer. What is
the name of this barrier?
A. cytoplasm
B. cell membrane
C. phospholipid barrier
D. cell wall
5. In carrying out normal activities, cells use oxygen and produce carbon dioxide. The
concentration of oxygen is higher in the blood than inside the cell, so oxygen moves into
the cell. Similarly, carbon dioxide moves out of the cell into the blood because the
concentration of carbon dioxide inside the cell is greater than the concentration outside
the cell.
How are the small molecules of oxygen and carbon dioxide moving through the cell
membrane?
A. passive transport by diffusion
B. active transport by endocytosis
C. passive transport by osmosis
D. active transport by carrier proteins
6. When dry environmental conditions exist, guard cells close the openings in leaves to
reduce the loss of water from the plant. This process is an example of a feedback
mechanism that plants use in order to
A. maintain homeostasis.
B. expend their resources.
C. produce more chlorophyll.
D. absorb more solar energy.
7. The components of the human body, from organ systems to cell organelles, interact to
maintain a balanced internal environment (homeostasis).
To successfully accomplish this, organisms possess many different control mechanisms
that detect deviations and make corrective actions.
For example, when there is an increase in muscle cell activity, the body responds by
I. increasing the heart rate.
II. increasing the respiratory rate.
III. producing more red blood cells.
IV. producing more hemoglobin.
A. I and II only
B. I, II, III and IV
C. I, II and III only
D. III and IV only
8. How is homeostasis important to the survival of organisms?
A. Homeostasis makes organisms grow bigger and taller.
B. Homeostasis makes all organisms hibernate.
C. Homeostasis allows organisms to regulate their temperature.
D. Homeostasis helps organisms locate food.
9. Emphysema is a health condition in which the lungs can no longer expel carbon
dioxide normally. As a result, a person who has emphysema may have high blood acidity
levels.
The body process that would attempt to return the blood pH to normal so that cells could
function properly is called _______.
A. homeostasis
B. active transport
C. acidosis
D. adaptation
10. Normal homeostatic conditions require potassium concentrations to be about 1000
times higher inside the cell than in the blood.
What mechanism does a cell use to move these small potassium molecules into the cell
against the concentration gradient?
A. passive transport by osmosis
B. active transport by endocytosis
C. passive transport by diffusion
D. active transport by proteins