Question

1. two scientists are given credit for discovering the final structure of dna. what are the names of those two scientists?
2. which scientists photographs were used without permission to help the two scientists above discover the structure of dna?
3. what is the name of the process of making a copy of the dna?
4. draw a sketch of what happens during each of the 3 steps when dna copies itself. underneath each picture, write a short description of what is taking place.
5. what is the name of the enzyme that unwinds dna?
6. what is the name of the enzyme that copies the dna/makes the new daughter strands?
7. before we knew what dna looked like, two scientists made major discoveries that started us down the road to understanding dna. describe the major discoveries of griffith & avery below (use textbook if needed):

griffith:
avery:

Explanation:

1. James Watson and Francis Crick are credited with discovering the final structure of DNA.
2. Rosalind Franklin's photographs (specifically her X - ray diffraction image of DNA, Photo 51) were used without permission.
3. The process of making a copy of DNA is called DNA replication.
4. The enzyme that unwinds DNA is helicase.
5. The enzyme that copies the DNA/makes the new daughter strands is DNA polymerase.
6. Griffith: In his experiments with Streptococcus pneumoniae, he discovered the "transforming principle". He showed that a non - virulent strain of bacteria could be transformed into a virulent strain when mixed with heat - killed virulent bacteria.

Avery: He and his colleagues built on Griffith's work. They purified different components (DNA, RNA, proteins etc.) from the heat - killed virulent bacteria. They showed that DNA was the "transforming principle" (the molecule responsible for transformation), not proteins or RNA.

Answer:

1. James Watson and Francis Crick
2. Rosalind Franklin
3. DNA replication
4. Helicase
5. DNA polymerase
6. Griffith: Discovered the "transforming principle" in bacteria. Avery: Showed that DNA was the "transforming principle".