Dna Test Part One: DNA Structure And Replication

Question 1

Chargaff’s rule

Answer 1

AT GC

Adenine thymine guanine cytosine

Question 2

Purines

Answer 2

One of the two nitrogenous bases that make up the nucleotide bases in RNA and DNA
Two carbon nitrogen ring bases adenine and guanine

Question 3

Pyrimidines

Answer 3

One of the two nitrogenous bases that make up the nucleotide bases in RNA and DNA
One carbon nitrogen ring bases thymine and cytosine

Question 4

Complimentary base

Answer 4

Either of the nucleotide bases linked by a hydrogen bond on opposite strands of DNA or double-stranded RNA

Question 5

Why are the bases complimentary

Answer 5

Complimentary base pairing is a set of rules that decides which bases go together. It keeps the DNA sequence relatively consistent and readable.
Because one strand of DNA can be used as a template to make another

Question 6

What type of bond holds bases together

Answer 6

Hydrogen bond

Relatively unstable

Question 7

How many bonds are formed between them

Answer 7

AT two

CG three

Question 8

Antiparallel

Answer 8

A term applied to two molecules that are side by side but run in opposite directions
the two strands of DNA run anti parallel

Question 9

3’ to 5’ ends

Answer 9

This terminology refers to the 5’ and 3’ carbons on the sugar
for both DNA (shown above) and RNA, the 5’ end bears a phosphate, and the 3’ end a hydroxyl group.

Question 10

Structure helps store information

Answer 10

DNA coils up so more information is stored

Sequence of bases serves as a recipe for proteins

Question 11

Structure helps copy informtation

Answer 11

Complementary base pairing allows the molecule to replicate

Hydrogen bond splits separating the two DNA strands each of which then serves as a template for a new strand

Question 12

DNA replicates semiconservatively

Answer 12

DNA replication is the process of making copies of DNA
DNA replicates by semi-conservative replication which means that one strand of the parent double helix is conserved in each new DNA molecule

Question 13

Polymerase

Answer 13

Joins individual nucleotides to produce the new strand of DNA

Question 14

Telomerase

Answer 14

Adds DNA at the end of chromosomes

Question 15

Telomeres

Answer 15

The ends of linear chromosomes, called telomeres, protect genes from getting deleted as cells continue to divide.

Question 16

Enzymes involved in DNA replication

Answer 16

Helicase
RNA primase
DNA polymerase
Ligase

Question 17

Differences between eukaryotes and prokaryotes in terms of structure and replication
Location of DNA
Amount of DNA
Starting points for replication
Structure

Answer 17

Prokaryotes
Cytoplasm/floats around
Less than eukaryotes
Single

Eukaryotes
Nucleus
X100+ Than prokaryotes
100+
Organelles

Question 18

Histones

Answer 18

Basic proteins that DNA wraps around

A structural unit of a eukaryotic chromosome, consisting of a length of DNA coiled around a core of histones

Question 19

Chromosome structure

Answer 19

Dna>Histones>Nucleosomes>Chromosome

Question 20

Three components of a nucleotide

Answer 20

The three components that make up a nucleotide are a sugar molecule, a phosphate molecule and one of the four nitrogenous bases adenine thymine cytosine guanine

Question 21

Backbone of DNA

Answer 21

QUICK ANSWER
The backbone of the DNA molecule is made of a repeated pattern containing a sugar called deoxyribose and a phosphate group

Question 22

Ladder of DNA

Answer 22

Adenine, guanine, thymine and cytosine are the four nitrogenous bases that are attached to a sugar molecule on each side of the ladder

Question 23

Nucleotide

Answer 23

When a phosphate a sugar and a base form an attachment they create a subunit of DNA called a nucleotide

Question 24

DNA replication steps

Answer 24

DNA Replication begins at the Origin of Replication

Step 2
Helicase cuts hydrogen bonds and separates DNA in half

Step 3
Single Strand Binding Proteins attach to the halfs and keep the DNA molecules separated (they are needed because the sides are attracted to each other and with out the Single Strand Binding Proteins they would move back together)

Step 4
The Replication Fork is forms with the Leading and Lagging strands.

Step 5
In the leading strand, RNA Primase moves along nucleotides and coats with a RNA Primer that will be used as a homing beacon for the DNA Polymerase.

Step 6
DNA polymerased attaches post primase to DNA nucleotides and move along towards the Replication Fork in 5 prime –> 3 Prime direction. It adds nucleotides to the half DNA molecules.

Step 7
Another type of Polymerase replaces the primer with DNA nucleotides so all DNA is there.

Step 8
8. Ligase stitches up the gaps.

Question 25

RNA primase

Answer 25

It goes over a single DNA strand and creates RNA sequences called primers, which transcribe DNA into RNA.

Question 26

Ligase

Answer 26

It seals repairs in the DNA, it seals recombination fragments, and it connects small DNA fragments formed during the replication of double-stranded DNA in eukaryotes