Higher Human Biology 1.2 Structure and Replication of DNA

Where is DNA stored in a cell?

• Nucleus

• Cytoplasm

• Cell membrane

• Ribosome

Identify the statement that best describes the structure of DNA.

• Double stranded, composed of repeating units called nucleotides, held together by hydrogen bonds.

• Single stranded, composed of repeating units called bases, held together by hydrogen bonds.

• Double stranded, composed of repeating units called nucleotides, held together by peptide bonds.

• Single stranded, composed of repeating units called nucleotides, held together by peptide bonds.

A nucleotide is composed of 3 parts. An organic base plus

• Hydrogen and a deoxyribose sugar.

• Hydrogen and ribose sugar.

• Phosphate and ribose sugar.

• Phosphate and deoxyribose sugar.

Identify the correct DNA base pairings from the list below.

• A-U, C-G

• C-T, A-G

• A-T, C-G

• G-U, A-C

Which type of bond can be found between the DNA base pairs?

• Peptide bonds

• Hydrogen bonds

• Ionic bonds

• Disulphide bridges

The 3' end of a DNa strand starts with a

• Phosphate

• Base

• Deoxyribose sugar

The two strands of DNA run parallel to each other.

• True

• False

When would DNA replicate in a cell?

• Before cell division.

• During cell division.

• After cell division.

• Never.

For DNA replicationto occur, the following materials are required; template strands, primers, enzymes and _________.

What name is given to a short complementry strand of nucleotides that bind to the 3' end of DNA to start the process of DNA replication?

• mRNA

• Primer

• tRNA

• Ligase