Cell Theory Quiz

Until about 200 years ago, most scientists accepted the theory of spontaneous generation. This theory states that organisms can arise (appear) from nonliving matter. Now scientists accept the cell theory to explain the origin and growth of new organisms. Which of these statements is a key idea of cell theory that disproves the theory of spontaneous generation?

• The cell is the basic unit of life

• All living things are made of matter

• All cells come from pre-existing cells

• All cells come from the combination of two other cells

Robert Hooke was a scientist who saw the first cork cells under a microscope in 1665, but it was not until 1839 that the cell theory gained the support it needed to be accepted. Why did it take 174 years for the cell theory to become widely accepted?

• Microscopes were very primitive in 1665, and no real progress was made on improving them until modern microscopes appeared in the early 1900s.

• Before the cell theory could be considered reliable and valid, a great number of organisms had to be examined and studied over time so that scientists could formulate conclusions about what cells are, how they function, and where they come from.

• When Hooke first proposed that all living things are made of cells, the public was so opposed to the idea that no one dared bring it up again for several generations.

• Scientists at the time were divided on whether or not cells were living things, and it took generations of debate, after the evidence was gathered, for a majority to win the debate.

Which of the following is true about theories?

• Theories may change depending on new evidence.

• Theories are opinions developed by scientists.

• Theories are the best explanations provided without any evidence.

• Theories are explanations that will never change.

Which of the following scenarios most accurately depicts the process of scientific theory formation?

• Roger has been working on an experiment for over two years. He keeps getting the same results and has come up with the best explanation he can for what he has observed.

• Zachary was working in a laboratory late one night and observed something he had never seen before. He has tried and tried to recreate the same conditions so he could observe the phenomenon again, but has not been successful. He has developed the best explanation for what he observed.

• Heloise, Stanley, and Dolores are colleagues in different countries. They have been working on separate experiments for several years and have collaborated to develop one explanation that covers what they each have observed. This theory may be altered with the findings of new investigations.

• Several years ago, Pedro developed an explanation based on results from an experiment. He shared those results with colleagues at a scientific meeting, but no one agreed with him. Earlier this year, Michaela conducted the same experiment and came up with a slightly different explanation based upon her results. Her theory will stay the same whether or not new evidence is presented.

Which of the following is a well-supported description about what happens in nature, that does not attempt to explain why it happens?

• Scientific law

• Scientific theory

• Both a scientific law and theory

• Scientific observations

Which of the following statements is NOT true regarding scientific theories and scientific laws?

• Theories are well-tested explanations for natural phenomena, and laws are specific descriptions of how some aspects of the natural world behave.

• Theories are complex and encompass a large number of ideas, while laws are more concise and describe how things will behave in certain situations.

• As new evidence is uncovered, a theory may be revised to become a scientific law.

• Both laws and theories are supported by many lines of evidence, observations, and experiments.

Microscopes can be used to explore cells. Which of the following types of microscopes is used to produce a three-dimensional image of the surface of a cell?

• simple light microscope

• compound light microscope

• scanning electron microscope

• transmission electron microscope

Which of the following items would be best examined under a dissecting microscope?

• A stained collection of cheek cells

• A thin sample of a protein molecule

• A seashell collected at the beach

• A DNA molecule

Scientists investigated how temperature affects the growth of the wood frog. Three groups of wood frogs were grown at different temperatures, as shown in the table below.

• Group 3 grew too quickly.

• Group 3 cannot grow in captivity.

• Group 3 had a tank that was too hot.

• Group 3 was outcompeted by Group 1 and Group 2.

Tags

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Science is a systematic approach to understanding the natural world through observation, experimentation, and analysis. It relies on evidence, logical reasoning, and repeatable results to draw conclusions about how the universe operates. Pseudoscience, on the other hand, may appear scientific but lacks the rigorous testing and validation required by true science. Beliefs, superstitions, and unfounded theories often fall into this category, as they are not grounded in empirical evidence or subject to peer review. Which of the following statements is most consistent with the definition of science as described in the passage?

• Astrology: predicts personality traits based on the positions of stars and planets at the time of birth, but it lacks empirical evidence and scientific validation.

• Homeopathy: claims to treat diseases with highly diluted substances, but its effectiveness is not supported by scientific studies or reproducible results.

• Alchemy: is a historical practice that aimed to transform base metals into gold, though it did not follow scientific principles or produce verifiable results.

• The Theory of Evolution: explains the diversity of life through natural selection, supported by extensive research, fossil evidence, and genetic studies.

Tags

NGSS.HS-LS4-1

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