Genetics Chapter: DNA Structure and Replication

Questions and Answers

What are genes composed of?

DNA

DNA is made up of what?

nucleotides

Each nucleotide is composed of what three things?

sugar, phosphate group, a base

Two strands of DNA are held together by what?

hydrogen bonds Signup and view all the answers

Nucleotides are linked together by what?

covalent bonds Signup and view all the answers

What is the function of DNA polymerase?

builds each new strand of DNA Signup and view all the answers

What are the three steps of DNA replication?

1). Protein unwinds DNA molecule and strands break apart 2). DNA polymerase uses template of old strands to build new strand 3). Semi-conservative replication; two new DNA double helices with an old and new strand Signup and view all the answers

What does PCR stand for?

polymerase chain reaction Signup and view all the answers

A change to the sequence of bases in an organism's DNA is called what?

mutation Signup and view all the answers

What is a change in a single base called?

point mutation Signup and view all the answers

What happens when a correct base is replaced by an incorrect one?

substitution Signup and view all the answers

What is it called when one or more bases are added to the sequence, changing the way it is read?

insertion Signup and view all the answers

What is it called when one or more bases are removed from the sequence, changing the way it is read?

deletion Signup and view all the answers

Study Notes

Genes and DNA Composition

Genes are composed of DNA, which carries genetic information.
DNA is made up of nucleotides, the building blocks of genetic material.

Nucleotide Structure

Each nucleotide consists of three components: sugar, phosphate group, and a nitrogenous base.

DNA Structure

Two strands of DNA are held together by hydrogen bonds, forming the double helix structure.
Nucleotides within a single strand are linked by covalent bonds, creating a stable backbone.

DNA Replication

DNA replication involves three main steps:
- Proteins unwind the DNA molecule, causing the strands to separate.
- DNA polymerase uses the template of the old strands to build new strands.
- The process results in semi-conservative replication, yielding two DNA double helices, each containing one old and one new strand.

Polymerase Chain Reaction (PCR)

PCR is a technique used to artificially produce millions of copies of a specific DNA sequence, facilitating genetic analysis.

Mutations

A mutation refers to any change in the sequence of bases in an organism's DNA.
Specific types of mutations include:
- Point mutation: a change in a single base within the sequence.
- Substitution: a correct base is replaced with an incorrect one, potentially altering gene function.
- Insertion: one or more bases are added, affecting the reading frame of the genetic code.
- Deletion: one or more bases are removed, also altering how the sequence is read.

Description

This quiz explores the fundamental concepts of genes and DNA, including nucleotide structures and the double helix formation. It also covers the critical process of DNA replication and the Polymerase Chain Reaction (PCR) technique. Test your understanding of these key genetic principles!