H. Genetics - Chapter 9 Test Study Guide

Griffith

experiment with type R and type S strands, started to lead to discoveries of DNA being the genetic materials

Hersey and Chase

proved that DNA is genetic material; experiment with tagging bacteriophages

Chargaff

% of A = % of T and % of C = % of G

Franklin

Used X-rays to find the basic shape of DNA

Watson and Crick

Published the basic shape of DNA

What is the relationship among the words gene, DNA, and protein?

Genes make up DNA. Genes are used to make proteins (instructions)

What forms the backbone?

phosphate

Where are the nitrogen bases? How are they paired? Difference between a purine and a pyrimidine?

Nitrogenous bases are the “rungs of the ladder,”

A + T, C + G

purine has two carbon rings (Adenine and Guanine are purines)

Pyrimidine have one carbon ring (thymine and cytosine)

What is a nucleotide? What makes up a nucleotide?

Repeating unit that makes up DNA

Made of deoxyribose sugar, a phosphate group, and a nitrogenous base

What does antiparallel mean?

DNA has a 5’ and 3’ end, and they run in opposite directions

If you have a parent strand 5’ TTACGC 3’ … what would be the complementary strand?

3’ AATGCG 5’

What are histones?

protein sphere that DNA wraps around to make a chromosome

If you have 100 total bases and 30 are adenine, how many bases are thymine? Cytosine?

A - 30

T - 30

C - 20

G - 20

What is semiconservative replication?

DNA saves one strand of parent DNA for each new DNA helix (1 double stranded parent becomes two double stranded daughters, each with one strand from the parent)

What is the purpose of DNA replication?

To copy DNA to make two daughter cells in mitosis

What is the job of helicase in the replication process?

unwind + unzip the DNA

What is the job of DNA polymerase in the replication process?

adds nucleotides to the 3’ end of DNA

What is the job of primase in the replication process?

makes the RNA primer

What is the job of ligase in the replication process?

glues the DNA together

What is the job of exonuclease in the replication process?

cuts out the RNA primer

What is the difference between the leading and lagging strand?

Leading strand is continuously replicated white the lagging strand is done in segments (Okazaki fragments)

What is a function/use for polymerase chain reaction (PCR)?

copy a small piece of DNA and make a lot of it; can be used for forensics or biomedical research

What are the three basic steps of PCR?

Denaturization - heat breaks the strands apart (breaks the Hydrogen bonds)

Annealing - primers attach to DNA strands

Extension - DNA is cooled and strands are built

Be able to explain the denaturation and annealing process of PCR.

Denaturation - DNA is heating to separate DNA

Annealing - primers attach to parent DNA