2.7 IB DNA Replication

Which is true about the relationship between enzymes and DNA?

• Both enzymes and DNA are made from proteins

• The base sequence of DNA is determined by which nucleotide DNA polymerase III attaches to the template strand

• The shape of a protein is due to the base sequence in the DNA that coded for it

• Both proteins and DNA are subject to denaturation

Answer explanation

Remember, DNA codes directly for proteins.

Tags

NGSS.HS-LS1-1

Which of the following units (monomers) are repeatedly joined together to form a strand of DNA?

• amino acids

• nucleotides

• fatty acids

• polysaccharides

Answer explanation

Tags

NGSS.HS-LS1-1

In a molecule of double-stranded DNA, the amount of adenine present is always equal to the amount of....

• cytosine
• guanine
• thymine
• uracil

Answer explanation

This is all thanks to our main man, Mr. Chargaff!

Tags

NGSS.HS-LS1-1

Replicate the following strand of DNA: 
AAT CAT GGA

• AAT CAT GGA
• TTA GTA CCT
• UUA GUA CCU
• GGA TAU CUA

Answer explanation

You need to know the which base pairs with which, there are no two ways around it.

Which is the order of replication?

• 3, 2, 1, 4
• 2, 1, 4, 3
• 2, 3, 1, 4
• 3, 4, 1, 2

Answer explanation

#1 break the h-bonds between the bases.

#2 after adding a primer, build each new strand by using the template strand and following complimentary base pairing.

#3 voila! We end up with two identical DNA strands which are semiconservative.

Tags

NGSS.HS-LS3-2

The enzyme that attaches the complimentary base pairs to the original strand of DNA is called...

• helicase

• DNA polymerase III

• replicase

• synthase

Answer explanation

The type of DNA polymerase is DNA polymerase III, but don't stress too much about it.

The enzyme that breaks the hydrogen bonds between the bases to prepare for replication....

• helicase

• replicase

• DNA polymerase III

• ligase

Answer explanation

Remember, helicase breaks the helix.

Nitrogenous bases are joined by which type of bond?

• polar bonds
• ionic bonds
• covalent bonds
• hydrogen bonds

Answer explanation

Hydrogen bonds are temporary which allows us to access the bases with relative ease.

Tags

NGSS.HS-LS1-1

If a DNA molecule is 18% Guanine which of the following is correct?

• 18% cytosine, 32% adenine, 32% thymine
• 32% cytosine, 18% adenine, 32% thymine
• 18% cytosine, 64% adenine, 64% thymine
• 32% cytosine, 32% adenine, 18% thymine

Answer explanation

18% G = 18% C (36% total)

32% A = 32% T (64%total)

The term used to describe DNA Replication is.....

• Semi-Conservative
• Conservative
• Anti-Parallel
• Parallel

Answer explanation

It is semi-conservative because part of the original DNA has been conserved in the new strand.