6.1.1 Molecular Genetics: The Protein vs. DNA Debate Flashcards Preview

AP Biology > 6.1.1 Molecular Genetics: The Protein vs. DNA Debate > Flashcards

Flashcards in 6.1.1 Molecular Genetics: The Protein vs. DNA Debate Deck (11)
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1
Q

Gregor Mendel

A
  • described factors that were responsible for passing traits on, but he did not know what the factors were.
2
Q

note

A

• A coordinated scientific effort to identify the genetic material occurred from the mid-1800s until the mid-1900s. At the beginning of the search, researchers formalized the qualities that the unknown genetic material must possess. They identified four qualities:

  1. ability to store information
  2. ability to replicate, or copy, itself
  3. ability to communicate with the cell, “cell communication”
  4. ability to change, or produce “new cell products”
    - During the 1800s and early 1900s, scientists who contributed to the understanding of the genetic material included Friedrich Miescher, Robert Feulgen, and Archibald Edward Garrod. During this time most scientists believed that protein, not DNA, was the genetic material.
3
Q

The four qualities of genetic material

A
  1. Information. It must store a relatively large amount of information, enough to produce all of the cell’s proteins and structures.
  2. Replication. It must be capable of copying itself because the information must be passed on to daughter cells.
  3. Communication. It must dictate the synthesis of cell products.
  4. Change. It must be capable of change in order to invent new cell products.
4
Q

Friedrich Miescher

A
  • In 1869, Friedrich Miescher extracted an acidic material from the nuclei of white blood cells. He called the material nucleic acid. Biochemists later determined that nucleic acid is made of four subunits called nucleotides. The type of nucleic acid found in the chromosomes of all eukaryotic cells is called deoxyribonucleic acid, or DNA.
5
Q

Robert Feulgen

A
  • In 1914, Robert Feulgendeveloped a staining technique that could quantify DNA. The more DNA present in the nuclei, the darker the stain. Using the technique, researchers found that DNA levels are species-specific. Within a given species the amount of DNA was relatively constant. Among species, however, it differed. Across all species, sex cells consistently contained half the amount of DNA that the autosomal cells did. In spite of the compelling data, most scientists at this time believed that protein was the genetic material.
6
Q

Archibald Edward Garrod

A
  • In 1908, Archibald Edward Garrod published the book,
    Inborn Errors of Metabolism, in which he described detailed studies of genetic diseases in humans, such as alkaptanuria or “maple syrup urine disease.” The disease is characterized by a buildup of a metabolic product, homogentisic acid, in the urine.
  • Garrod observed that metabolic disorders have a hereditary component and can be traced in family trees. He hypothesized that a defect in a specific gene results in the absence of a specific enzyme, changing an important metabolic pathway. Garrod’s hypothesis has since been found to be correct. Scientists contemporary to Garrod misinterpreted his data to mean that protein was the genetic material.
7
Q

True or false?

All cells in the body have the same amount of DNA except sex cells, which have twice as much.

A
  • false
8
Q

Who first extracted nucleic acid (DNA) from white blood cells?

A
  • Friedrich Miescher
9
Q

Which of the following is not a basic quality of the genetic material?

A
  • It must be capable of mutating after every round of replication
10
Q

Concerning A.E. Garrod’s work, which of the following is not a true statement?

A
  • He was able to definitively link defective enzymes with defective DNA
11
Q

Robert Feulgen is attributed with

A
  • developing a staining technique for DNA

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