Section outline

  • General

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  • 科学理论

    What you will learn
    ::你会学到什么

    • How hypotheses become scientific theories
      ::假设如何成为科学理论
    • Examples of scientific theories in biology : theory of evolution, , and germ theory
      ::生物学科学理论的例子:进化理论、细菌理论

     

    Colorful representations of various microorganisms, including bacteria and viruses, on a white background.

    Theory vs. theory. Is a scientific theory different from the everyday use of the word theory?
    ::理论理论与理论理论的日常使用是否不同?

    A scientific theory is accepted as a scientific truth , supported by evidence collected by many scientists. The  germ theory of disease is a classic scientific theory in biology.
    ::科学理论被接受为科学真理,并得到了许多科学家收集的证据的支持。 病菌病理理论是生物学的经典科学理论。

    Scientific Theories
    ::科学理论

    With repeated testing, some hypotheses may eventually become scientific theories. Keep in mind, a hypothesis is a possible answer to a scientific question. A scientific theory is a broad explanation for events that is widely accepted as true. To become a theory, a hypothesis must be tested over and over again, and it must be supported by a great deal of evidence.
    ::通过反复试验,某些假设最终可能变成科学理论。 记住,假设是对科学问题的可能答案。 科学理论是对被广泛接受为真实的事件的广泛解释。 要成为理论,一个假设必须一次又一次地检验,并且必须有大量证据支持。

    Many people think that any idea that is completely accepted in science is a law , but that is not true. In science, a law is something that always applies under the same conditions. A theory is much more complex: it explains why something happens. A law only describes what happens. Additionally, p eople commonly use the word theory to describe a guess about how or why something happens. For example, you might say, “I think a woodchuck dug this hole in the ground, but it’s just a theory.” Using the word theory in this way is different from the way it is used in science. A scientific theory is more like a fact than a guess because it is so well-supported.   There are several well-known theories in biology, including the theory of evolution, cell theory, and germ theory.
    ::许多人认为,科学中完全被接受的任何思想都是法律,但事实并非如此。在科学中,法律总是在相同条件下适用。一个理论更为复杂:它解释了发生某事的原因。一个法律只描述发生的事情。此外,人们通常使用这个词来描述某事发生的方式或原因。例如,你可以说 , “ 我认为木匠在地上挖了这个洞,但这只是一个理论 ” 。 以这种方式使用这个词理论与在科学中使用它的方式不同。 科学理论更像是事实而不是猜想,因为它有很强的支持。 在生物学中,有几个著名的理论,包括进化理论、细胞理论和细菌理论。

     

     

    The Theory of Evolution
    ::进进理论理论理论

    The theory of evolution by natural selection is a scientific theory. Evolution is a change in the characteristics of living things within a over time. Evolution occurs by a process called . In natural selection, some living things produce more offspring than others, so they pass more genes to the next generation than others do. Over many generations, this can lead to major changes in the characteristics of living things. The theory of evolution by natural selection explains how living things are changing today and how modern living things have descended from ancient life forms that no longer exist on Earth. No evidence has been identified that proves this theory is incorrect. More on the theory of evolution will be presented in additional concepts.
    ::自然选择的进化理论是一种科学理论。进化是生命特性在一段时间内的变化。进化是由一个叫作自然选择的过程发生的。在自然选择中,一些生物比其他生物产生更多的后代,因此它们将更多的基因传给下一代。在许多代人中,这可能导致生命特性的重大变化。自然选择的进化理论解释了生命事物如何在今天发生变化,现代生命事物是如何从地球上不再存在的古代生命形式中诞生的。没有找到证据证明这一理论是不正确的。进化理论将更多地体现在其他概念中。

    The Cell Theory
    ::细胞理论

    The cell theory is another important scientific theory of biology. According to the cell theory , the is the smallest unit of structure and function of all living organisms , all living organisms are made up of at least one cell, and living cells always come from other living cells. Once again, no evidence has been identified that proves this theory is incorrect. More on the cell theory will be presented in additional concepts.
    ::细胞理论是生物学的另一个重要科学理论。 根据细胞理论,细胞是所有活生物体结构和功能中最小的单位,所有活生物体都由至少一个细胞组成,活细胞总是来自其他活细胞。 再一次,没有发现任何证据证明这一理论不正确。 关于细胞理论的更多内容将在其他概念中提出。

    The Germ Theory
    ::格姆理论

    The germ theory of disease, also called the pathogenic theory of medicine, is a scientific theory that proposes that microorganisms are the cause of many diseases. Like the other scientific theories, lots of evidence has been identified that supports this theory, and no evidence has been identified that proves the theory is incorrect.
    ::疾病细菌理论 — — 也被称为医学病原体理论 — — 是一个科学理论,它表明微生物是许多疾病的原因。 与其他科学理论一样,许多证据已经确定支持这一理论,而没有证据证明理论不正确。

    DID YOU KNOW?
    The germ theory of disease was confirmed by Robert Koch and Louis Pasteur in the late nineteenth century through a series of . They were able to establish that diseases like anthrax , rabies, plague, cholera, and tuberculosis were caused by microorganisms. Louis Pasteur and Robert Koch are rightly known as ‘Father of microbiology’ and ‘Father of bacteriology’ respectively for their contributions. 
     

     

    Summary
    ::摘要

    • With repeated testing, some hypotheses may eventually become scientific theories. A scientific theory is a broad explanation for events that is widely accepted as true.
      ::通过反复试验,某些假设最终可能变成科学理论。 科学理论是对被广泛接受为真实的事件的广泛解释。
    • Evolution is a change in species over time. Evolution occurs by natural selection.
      ::进化是物种随时间变化的一种变化。进化通过自然选择发生。
    • The cell theory states that all living things are made up of cells, and living cells always come from other living cells.
      ::细胞理论指出,所有生物都是由细胞组成的, 活细胞总是来自其他生物细胞。
    • The germ theory proposes that microorganisms are the cause of many diseases.
      ::细菌理论认为微生物是许多疾病的根源。

    Review
    ::回顾

    1. Contrast how the term theory is used in science and in everyday language.
      ::与理论在科学和日常语言中的用法对比。
    2. Explain how a hypothesis could become a theory.
      ::解释一个假设如何成为理论。
    3. Describe the evidence that proves the cell theory is incorrect.
      ::描述证明细胞理论错误的证据