DNA Basics
What does DNA stand for?
Deoxyribonucleic Acid
A gene is best defined as what?
A segment of DNA that codes for the production of a protein.
During which cell cycle phase does DNA replication occur?
Interphase (S phase)
Which enzyme unwinds the DNA helix by cutting the hydrogen bonds between the nitrogenous bases?
Helicase
A gene is best defined as what?
A segment of DNA that codes for the production of a protein.
What are the subunits of DNA called?
Nucleotides
The genetic code is determined by the sequence of ________ within the DNA molecules.
Bases
What is the main function of DNA replication?
To make identical copies of DNA so each new daughter cell gets the same genetic information.
Which enzyme is responsible for adding new nucleotides and editing the final DNA molecule?
DNA polymerase
A human somatic cell contains how many chromosomes?
46
What sugar is found in DNA?
Deoxyribose
Which bases pair together in a DNA molecule:
______ with ______
______ with ______
Adenine with Thymine
Cystone with Guanine
What is the terminology for the DNA replication model that produces a DNA molecule with one new strand and one old strand of DNA?
The semiconservative model.
What molecules stabilize the individual DNA strands once the hydrogen bonds between bases have been broken?
Singe strand binding proteins (SSB's)
The form of DNA when it is wrapped around histones is called?
Chromatin
The structure of DNA is referred to as a _________
(2 words).
Double helix
The two strands of DNA run in what orientation to each other?
Antiparallel
The Y-shaped region within the replication bubble where the DNA is unwound is called the _________.
(2 words)
Replication fork.
The enzyme that binds DNA fragments together is called ________
Ligase
What does the chromosome theory of inheritance state?
The chromsomes carry genetic information that code for traits.
What are the three components that make up a nucleotide?
A phosphate group, a deoxyribose sugar, and a nitrogenous base.
A group of 3 bases that codes for one amino acid is called a ______.
Codon.
Small DNA fragments made on the lagging strand of DNA during replication are called __________.
(2 words)
Okazaki fragments
Which enzyme relieves the strain of coiling ahead of the replication fork on the DNA molecule?
Topoisomerase
The process of crossing over increases genetic variation by swapping genetic material between a maternal and paternal homologous chromosome. During which phase of Meiosis does this occur?
Prophase I.