Question

8.3 cell transport hs - ls1 - 2, hs - ls1 - 3

1. the relatively constant internal physical and chemical conditions that all organisms must maintain to survive is known as

a. osmosis. c. homeostasis.
b. endocytosis. d. exocytosis.

1. solute particles move from an area of higher concentration to an area of lower concentration in a process called

a. osmosis. c. diffusion.
b. transport. d. equilibrium.

1. large molecules such as glucose move across cell membranes through special protein channels during

a. active transport.
b. facilitated diffusion.
c. osmosis.
d. bulk transport.

1. what is the term that describes the diffusion of water through a selectively permeable membrane?
2. explain why cells are almost always hypertonic to fresh water.
3. what is the main difference between passive transport and active transport of materials across a cell membrane?
4. what are the two types of active transport, and how do they differ?

8.4 homeostasis and cells hs - ls1 - 2, hs - ls1 - 3

1. which type of organism consists of specialized cells?

a. unicellular prokaryotes
b. multicellular prokaryotes
c. unicellular eukaryotes
d. multicellular eukaryotes

1. all unicellular organisms

a. are prokaryotes.
b. are bacteria.
c. reproduce.
d. have a nucleus.

1. in what way does specialization of cells contribute to maintaining homeostasis in multicellular organisms?
2. describe the levels of organization in a multicellular organism.
3. in general, how do cells in a multicellular organism communicate?

critical thinking hs - ls1 - 1, hs - ls1 - 2, hs - ls1 - 3

1. evaluate models cells are often compared to factories. how is a factory a useful model for explaining the cell?
2. evaluate reasoning a student is asked to classify examples of cells based on prepared microscope slides. the student classifies the cells according to their most prominent color. evaluate the student’s classification scheme.
3. construct an explanation in a multicellular organism, the dna in every cell is essentially the same. how does the cell theory help explain this?
4. apply scientific reasoning the beaker shown here has a membrane that separates two solutions. water can pass through the membrane, but starch cannot pass through it. how will the fluid levels change over time? explain your prediction.
5. critique in constructing a model of a plant cell, a student surrounds the model with plastic bricks. the bricks represent the cell wall. how could the model be improved to represent the cell wall more accurately?
6. synthesize information why is intercellular communication essential for a multicellular organism to function properly?
7. infer pacemakers are devices that help keep heart muscles contracting at a steady rate. if a person needs a pacemaker, what does that suggest about his or her heart cells’ ability to send and receive messages?
8. plan an investigation you want to know how temperature affects the rate of diffusion. describe an investigation that would provide evidence to support a conclusion. include simple materials such as water and food coloring.

Answer:

1. c. homeostasis
2. c. diffusion
3. b. facilitated diffusion
4. Osmosis
5. Cells have a higher solute concentration than fresh water due to dissolved salts, proteins etc.
6. Passive transport does not require energy (moves with the concentration gradient), while active transport requires energy (moves against the concentration gradient).
7. Primary (uses ATP directly) and secondary (uses energy from an electrochemical gradient)
8. d. multicellular eukaryotes
9. c. reproduce
10. Specialized cells perform specific functions that contribute to overall homeostasis.
11. Cells, tissues, organs, and organ - systems
12. Through chemical signals (hormones, neurotransmitters), gap junctions etc.
13. Different parts of a factory can be compared to different organelles and structures in a cell that perform specific functions.
14. Classifying cells based on color is not valid as color is not a fundamental characteristic for cell classification.
15. All cells come from pre - existing cells, and all cells in a multicellular organism originate from a single zygote.
16. Water will move from side B to side A by osmosis. The fluid level on side A will rise and on side B will fall.
17. Make the plastic bricks more porous to represent the pores in the real cell wall.
18. It coordinates activities such as growth, development, and response to stimuli among different cells and tissues.
19. The heart cells' ability to send and receive messages to maintain a regular heartbeat is impaired.
20. Fill three beakers with water at different temperatures (cold, room - temperature, hot). Add a drop of food coloring to each beaker at the same time and observe how quickly the color spreads. The food coloring will diffuse faster in the hot water and slower in the cold water.