Cell theory, cell membrane, comparing plant and animal cells

Which of the following explains why cell theory will not ever become the law of cells?

• A.Scientific theories are well-tested explanations, while laws are well-tested descriptions of natural phenomena; one cannot become the other.

• B.Cells of different organisms are so diverse that it is impossible to come up with a law that would apply to all of them.

• C. Because cells undergo change as mutations occur within them, developing anything beyond a cell theory would be impractical.

• D. Scientific theories can only become laws if all possible cases can be tested; it would be impossible to test all living things to see if they have cells.

The goal of scientific experimentation is to increase what we know about how the natural world operates. If a hypothesis is tested repeatedly by a wide variety of experimental approaches in many scientific investigations and cannot be proved false, then the hypothesis could be called a

• A. conclusion.

• B. fact.

• C. rule.

• D. theory.

Cell theory is a result of the contributions of several different scientists, and applies to all living things. Which of the following explains why cell theory will not ever become the law of cells?

• A.Cells of different organisms are so diverse that it is impossible to come up with a law that would apply to all of them.

• B. Because cells undergo change as mutations occur within them, developing anything beyond a cell theory would be impractical.

• C.Scientific theories are well-tested explanations, while laws are well-tested descriptions of natural phenomena; one cannot become the other.

• D.Scientific theories aren't well-tested explanations, but, laws are well-tested descriptions of natural phenomena; one cannot become the other.

Because the function of most plant leaves is to carry out photosynthesis, their cells contain many more of what organelle than other parts of the plants?

• A. Chloroplasts

• B. Mitochondria

• C. Nuclei

• D. Vacuoles

Tags

NGSS.HS-LS1-5

NGSS.HS-LS2-5

Which of these statements is a key idea of the cell theory that disproves the theory of spontaneous generation?

• A. ¨The cell is the basic unit of life.

• B. ¨All living things are made of matter.

• C. ¨All cells arise from pre-existing cells by division.

• D. All cells are formed from the combination of two other cells.

After the invention of the microscope, biologists were able to look at organisms on a microscopic scale. The new data that they collected with this instrument led to what theory?

• A. Atomic Theory

• B. Cell Theory

• C. Theory of Inheritance

• D. Theory of Organic Evolution

¨Which of the following accurately states a difference between plant and animal cells?

• A. Animal Cells have stomata that allow for the exchange of gases.

• B. Plant cells have thylakoids that are sites of chemical reactions.

• C. Plant cells have stromal cells that make up connective tissue.

• D. Animal cells have chloroplasts that turn glucose into ATP.

¨If you examined a cell under a microscope and found it had a nucleus and other organelles, how would you classify the cell.

• A. It is a plant cell.

• B. It is an animal cell.

• C. It is a eukaryotic cell.

• D. It is a prokaryotic cell.

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NGSS.MS-LS1-1

NGSS.MS-LS1-2

¨Bacteria are prokaryotic cells, while multicellular and more sophisticated single-celled organisms are eukaryotic. Which of these describes a prokaryotic cell and NOT a eukaryotic cell?

• A. Sunlight is absorbed by chloroplasts in the cell.

• B. ¨Molecules join together to assemble a permeable cell membrane.

• C. ¨The nuclear membrane disassembles and chromosomes align in a cell.

• D. DNA is distributed loosely within the cell rather than in chromosomes.

Tags

NGSS.MS-LS1-1

NGSS.MS-LS1-2

A cell membrane is composed of a double layer of lipids in which many kinds of proteins are embedded. Many of these proteins act like gates, allowing only certain particles to enter or leave the cell. When a particle has to go against its concentration gradient through one of these gates, energy is supplied by the cell to the correct protein to move the particle through the membrane. Which type of cell transport is acting?

• A. Diffusion

• B. Passive Transport

• C. Osmosis

• D. Active Transport