Unit 7: DNA & Mitosis Flashcards
Who are Watson & Crick?
They made a 3-D model of DNA using Franklin’s x-rays. For this discovery, they won the Nobel Peace Prize for their scientific achievement.
Who is Rosalind Franklin?
She took an x-Ray of a DNA molecule. She proved that DNA was Double Helix.
Where is DNA stored? What is its shape? What is DNA made of?
- DNA is stored in the nuclease of cells.
- Shape is a double helix.
- Made up of building blocks called nucleotides.
What is a double helix?
- 2 spirals wound around each other.
- Twisted ladder
What is DNA made of? (3 parts)
- Phosphate
- Sugar
- Nitrogenous Base
What are the 4 nitrogenous bases that make up the “steps” of the ladder? Which bases pair together? How many hydrogen bonds between each pair?
- Adenine (A)
- Thymine (T)
- Guanine (G)
- Cytosine (C)
Bases pair together: A–, G—C
What does it mean for DNA to be complementary?
Bases on one strand match up with the bases on the other strand.
What is Chargaff’s Rule?
- The amount of A = the amount of T
- The amount of G = the amount of C
Which of the nitrogenous bases are purines? Which of the nitrogenous bases are pyridimines?
Adenine & Guanine = Purines
Thymine & Cytosine = Pyridimines
What is DNA replication? Describe the steps.
- The process by which DNA copies itself to make a new cell.
- Enzymes uncoil the helix & “unzip” the bases.
- Each unzipped strand of DNA serves as a template for building a new DNA molecule.
- Nucleotides free floating in the cytoplasm bond to the old strand, creating two identical DNA molecules.
- Each new piece of DNA is made up of 1 old stand and 1 new strand.
A chromosome is made of _______, a segment of DNA is a ____________, a gene contains the code for making a ___________, and proteins determine the variation of _________.
DNA, gene, protein, traits
What enzyme the bases of free nucleotides to the bases on the parent strand?
DNA polymerase
