Nucleotides and DNA Structure Quiz

Questions and Answers

What are the three parts of a nucleotide?

Phosphate, Ribose Sugar, Nitrogen Base

Nitrogen Base, Deoxyribose Sugar, Lipid

Phosphate, Deoxyribose Sugar, Nitrogen Base (correct)

Phosphate, Deoxyribose Sugar, Glycoprotein

What kind of sugar is found in a nucleotide?

Deoxyribose Sugar

Which nucleotide component contains nitrogen?

Base

Name the four nitrogen bases.

Adenine, Thymine, Guanine, Cytosine Signup and view all the answers

What part(s) of the nucleotides make up the rungs of the 'ladder'?

Nitrogen Bases Signup and view all the answers

What parts of the nucleotides make up the sides (backbone) of the 'ladder'?

Phosphate Signup and view all the answers

Are the rungs parallel or antiparallel?

Antiparallel Signup and view all the answers

When one nucleotide contains adenine, what type of base is the adenine attached to on the opposite nucleotide strand?

Thymine Signup and view all the answers

How many hydrogen bonds connect the two bases from Question 4?

2 Signup and view all the answers

When one nucleotide contains cytosine, what type of base is the cytosine attached to on the opposite nucleotide strand?

Guanine Signup and view all the answers

How many hydrogen bonds connect the two bases from Question 6?

3 Signup and view all the answers

Use a complete sentence to write a rule for how the bases are arranged in the ladder model of DNA.

In the structure of DNA, the bases match up in a specific manner; guanine pairs with cytosine, and thymine pairs with adenine. Signup and view all the answers

Fill in the complementary bases on the strand below according to the base-pair rule.

T A G G T C Signup and view all the answers

Hydrogen bonds between nucleotides form.

4 Signup and view all the answers

Hydrogen bonds between nucleotides break.

1 Signup and view all the answers

Strands of DNA separate.

2 Signup and view all the answers

Free nucleotides are attracted to exposed bases on the loose strands of DNA.

3 Signup and view all the answers

What type of biological molecule is DNA helicase?

Enzyme Signup and view all the answers

What is the role of DNA helicase in replication of DNA?

Breaks DNA parts Signup and view all the answers

What rule is used to join the free nucleotides to the exposed bases of DNA?

Complementary base pair rule Signup and view all the answers

Explain why DNA replication is called semi-conservative.

When the double helix breaks, new strands get some new DNA and some old DNA. Signup and view all the answers

How does semi-conservative replication help prevent mutations during DNA replication?

Chance of correct copying in one half is the original. Signup and view all the answers

What term refers to loose DNA inside of a nucleus?

Chromatin Signup and view all the answers

During what part of the cell cycle is the DNA in a cell's nucleus replicated?

Synthesis Signup and view all the answers

During what part of the cell cycle is the DNA in a cell condensed into chromosomes?

Mitosis Signup and view all the answers

What structure holds the two sister chromatids together as they prepare for cell division?

Centromere Signup and view all the answers

Study Notes

Nucleotides and Their Components

Three parts of a nucleotide: Phosphate, Deoxyribose Sugar, Nitrogen Base.
Sugar found in nucleotides is Deoxyribose.
Nitrogen bases: Adenine, Thymine, Guanine, Cytosine.

Structure of DNA

Rungs of the DNA "ladder" are formed by Nitrogen Bases.
Sides (backbone) of the "ladder" are made up of Phosphate groups.
DNA strands are arranged in an antiparallel configuration.

Base Pairing Rules

Adenine pairs with Thymine; this forms 2 hydrogen bonds.
Cytosine pairs with Guanine; this forms 3 hydrogen bonds.
Specific pairing rules: Guanine pairs with Cytosine, and Thymine pairs with Adenine.

DNA Replication Process

DNA helicase is an enzyme that breaks DNA strands.
During replication, free nucleotides match exposed bases according to the complementary base pairing rule.
DNA replication is described as semi-conservative; each new DNA molecule contains one original and one new strand.

Prevention of Mutations

Semi-conservative replication maintains original sequence integrity, thus reducing the chance of mutations.

Chromatin and Cell Cycle

Loose DNA within the nucleus is referred to as Chromatin.
DNA replication occurs during the Synthesis phase of the cell cycle.
DNA is condensed into chromosomes during Mitosis.
Sister chromatids are held together by a structure called the Centromere.

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Description

Test your knowledge on the components of nucleotides and the structure of DNA. This quiz covers details about nucleotide parts, base pairing rules, and the DNA replication process. Perfect for biology students looking to reinforce their understanding of molecular genetics.