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What are the parts of a DNA nucleotide?
- 1. A 5-carbon deoxyribose sugar
- 2. A phosphate group
- 3. A nitrogenous base
Who was Frederick Griffith?
He was a scientist in 1928 who worked with mice and pneumonia and determined that one strain could be passed to another. He called this transformation.
Who were Alfred Hershey and Martha Chase?
They were scientists who in 1952 determined that DNA is the molecule that carries the genetic code.
Who was Rosalind Franklin?
- The scientist who used x-rays to determine the structure of DNA.
- She discovered that DNA is twisted, double-stranded and that the molecules within DNA are evenly spaced.
Who were James Watson and Francis Crick?
They wre scientists in 1953 who were given credit for determining the overall shape of DNA. They used wire and clay to create models of DNA, and won the Nobel Prize in 1962.
What is the function of DNA?
DNA carries the genetic code and it is the molecule of heredity.
Where is DNA located?
The nucleus of a eukaryotic cell.
What is the shape of a DNA molecule?
- A double helix (double standed and spiral shaped twisted ladder)
What are the parts of a DNA molecule?
- 1. Nitrogenous bases (adenine, guanine, cytosine, thymine)
- 2. Phosphate group (backbone)
- 3. 5-carbon deoxyribose sugar (backbone)
- 4. Hydrogen bond (hold nitrogenous bases together)
Explain DNA replication.
- Before a cell divides, the DNA in its nucleus must be copied so the new cell has its own copy of DNA.
- 1. An enzyme unzips the double stranded DNA
- 2. Each strand is copied by adding the complementary nitrogen base pairs, sugars, and phosphates.
- 3. Enzymes proofread the nitrogen bases to make sure the pairings are correct
- DNA replication is semi-conservative because a strand of the parent DNA is found in each cell
What bases pair with each other in a DNA molecule?
- Adenine pairs with Thymine
- Cytosine pairs with Guanine