Turning Points in Science

by Vocafy Geverifieerd

Engels (VS) C1 Vragen (10) Science History & culture

Explore the experiments and discoveries that reshaped our view of life, Earth, and the universe—and why their evidence mattered.

1. 1. Kies het juiste antwoord.

   What did this result show about microbial growth?

   Pasteur boiled broth in flasks whose curved necks let air in but trapped dust. The broth remained clear until it came into contact with the trapped dust.

   • Microbes formed spontaneously whenever the broth contained nutrients.
   • Microbial growth resulted from contamination rather than from the broth itself.
   • Boiling made the broth permanently unable to support microbes.
   • Exposure to air alone inevitably produced microbes in the broth.

   Air could enter the flask before any growth appeared.

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   • Microbial growth resulted from contamination rather than from the broth itself.

   The curved neck separated exposure to air from exposure to dust. This helped rule out spontaneous generation under the conditions tested.

2. 2. Kies het juiste antwoord.

   Why would penicillin alone not treat influenza?

   Penicillin disrupts the construction of bacterial cell walls. Viruses have no such walls and reproduce inside host cells.

   • Penicillin cannot reach infections in the respiratory system.
   • The influenza virus has a thicker cell wall than most bacteria.
   • The structure penicillin targets is absent from the influenza virus.
   • Penicillin suppresses symptoms without acting on the cause of an infection.

   Consider whether the treatment's target exists in both kinds of pathogen.

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   • The structure penicillin targets is absent from the influenza virus.

   Antibiotics can treat a separate bacterial infection that develops alongside influenza, but they do not cure the flu itself.

3. 3. Kies het juiste antwoord.

   What could Galileo conclude from this observation alone?

   Galileo observed small objects repeatedly circling Jupiter. They were moons orbiting another planet, not objects traveling around Earth.

   • Some celestial objects orbit a body other than Earth.
   • Every planet must have its own moons.
   • Earth must orbit Jupiter.
   • The Sun must be the center of every orbit.

   Distinguish what was directly observed from broader claims about the whole solar system.

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   • Some celestial objects orbit a body other than Earth.

   Jupiter's moons challenged the idea that everything revolved around Earth. This observation alone did not establish Earth's orbit around the Sun.

4. 4. Kies het juiste antwoord.

   What best accounts for the metal's gain in mass?

   Lavoisier heated a metal in a sealed vessel. The metal gained mass, while the total mass of the vessel and everything inside it stayed the same.

   • Heating created new matter that became part of the metal.
   • The metal released some of its matter into the trapped air.
   • Additional matter entered the sealed vessel from the surrounding air.
   • The metal combined with a component of the air already inside the vessel.

   Account for both the metal's increased mass and the unchanged total mass.

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   • The metal combined with a component of the air already inside the vessel.

   The metal gained oxygen from the trapped air. The reaction rearranged matter within the vessel rather than creating new matter.

5. 5. Kies het juiste antwoord.

   How could the population change over several generations?

   A drought left mostly hard seeds on an island. Finches with inherited beak shapes suited to cracking those seeds were more likely to survive and reproduce.

   • Every bird would develop a stronger beak through effort and pass that acquired change to its offspring.
   • Inherited beak shapes suited to hard seeds could become more common.
   • Useful new beak shapes would appear because the birds recognized what they needed.
   • All variation in beak shape would disappear after a single generation.

   Focus on which birds leave more offspring, not on individual birds changing deliberately.

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   • Inherited beak shapes suited to hard seeds could become more common.

   Natural selection changes how common inherited traits are. It does not require organisms to anticipate what would help them survive.

6. 6. Kies het juiste antwoord.

   Which process best explains both patterns?

   Ocean-floor rocks show matching bands of magnetic direction on opposite sides of a mid-ocean ridge. The rocks also become progressively older farther from the ridge.

   • Old ocean crust moves toward the ridge and melts at its center.
   • New ocean crust forms near continental margins and moves inward toward the ridge.
   • New ocean crust forms at the ridge and moves outward on both sides.
   • The ocean floor remains stationary while all its rocks continually adopt the current magnetic direction.

   The youngest rocks mark where new material is being added.

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   • New ocean crust forms at the ridge and moves outward on both sides.

   Cooling lava preserves the direction of Earth's magnetic field. The matching bands became powerful evidence for seafloor spreading and plate tectonics.

7. 7. Kies het juiste antwoord.

   What made this a turning point in measuring geological time?

   Radioactive atoms change into other kinds of atoms at known rates. By measuring their proportions in suitable minerals and accounting for the sample's history, scientists can estimate when those minerals formed.

   • It provided a physical clock independent of human records.
   • It established that every rock on Earth formed at the same moment.
   • It made a rock's age depend only on how deeply it was buried.
   • It removed the need to investigate whether a sample had been altered.

   Consider what connects the measurement to elapsed time.

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   • It provided a physical clock independent of human records.

   Radiometric dating opened a window onto time far beyond written history. A mineral's date does not automatically represent the age of Earth itself.

8. 8. Kies het juiste antwoord.

   Which conclusion is best supported for these viruses?

   Researchers separately tagged the DNA and protein coats of viruses that infect bacteria. During infection, the DNA label mainly entered the cells, while the protein label largely stayed outside. The infected cells then produced new viruses.

   • Every kind of virus stores its genetic information in DNA.
   • Proteins have no role in any stage of viral reproduction.
   • The bacteria supplied all the genetic instructions without receiving viral material.
   • DNA, rather than the outer protein coat, carries inherited instructions in this viral system.

   Keep the conclusion within the scope of the system studied.

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   • DNA, rather than the outer protein coat, carries inherited instructions in this viral system.

   This experiment helped establish DNA's role in inheritance. Some other viruses use RNA, so the finding should not be extended to every virus.

9. 9. Kies het juiste antwoord.

   Which account best fits these observations?

   On a particular metal surface, intense red light released no electrons, while faint ultraviolet light did. Increasing the ultraviolet light's intensity released more electrons but did not raise their maximum energy.

   • Light releases electrons whenever its total intensity is high enough, regardless of frequency.
   • Light transfers energy in individual packets whose energy depends on frequency.
   • Every color of light delivers individual packets with the same energy.
   • Increasing intensity raises the energy of each light packet without changing the number of packets.

   Separate the amount of light arriving from the energy delivered in each interaction.

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   • Light transfers energy in individual packets whose energy depends on frequency.

   Brighter light supplies more photons; higher-frequency light supplies more energy per photon. Releasing an electron requires a minimum energy per photon.

10. 10. Kies het juiste antwoord.

    How did relativity change the status of Newton's theory?

    Newton's laws give highly accurate predictions at ordinary speeds and in weak gravitational fields. Relativity explains measurable differences at very high speeds or in strong gravity while closely matching Newton's predictions in everyday conditions.

    • It showed that Newton's theory and relativity are equally precise under every condition.
    • It made Newton's agreement with everyday observations irrelevant to the theory's usefulness.
    • It defined the conditions in which Newton's theory remains a reliable approximation.
    • It established that any theory useful in daily life must also be exact in extreme conditions.

    A model can have limits without losing all practical value.

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    • It defined the conditions in which Newton's theory remains a reliable approximation.

    Scientific progress can extend an older model rather than erase it. Engineers still use Newton's laws when relativistic effects are too small to matter.