Biology CPE: DNA Test - Roberts

What is the full name of DNA?

deoxyribonucleic acid

What is the monomer of DNA called?

nucleotide

What 3 parts make up a nucleotide?

phosphate group, deoxyribose sugar, nitrogenous base

Which nitrogenous bases are purines?

adenine and guanine

Which nitrogenous bases are pyrimidines?

cytosine and thymine

What are the base pairing rules?

A-T and C-G

What did Chargaff discover?

A = T and C = G in any DNA sample

What did Franklin's X-ray images show?

DNA is a double helix with a constant width

What did Watson and Crick do?

Created the 3D double helix model of DNA

Where are covalent bonds found in DNA?

Between sugars and phosphates in the backbone

Where are hydrogen bonds found in DNA?

Between nitrogenous bases

Why does A pair with T and C with G?

Base pairing ensures constant helix width: purine + pyrimidine

What does 'antiparallel' mean in DNA?

The two strands run in opposite directions

During what phase does DNA replicate?

S phase of interphase

What is DNA replication?

Process of copying DNA before cell division

What is semiconservative replication?

Each new DNA has one old strand and one new strand

What enzyme unzips DNA?

Helicase

What enzyme adds new nucleotides?

DNA polymerase

What ensures accuracy in DNA replication?

DNA polymerase proofreading

What are replication bubbles?

Openings where replication begins and spreads in both directions

What is transcription?

Process of copying DNA into RNA

Where does transcription happen?

In the nucleus

What enzyme builds RNA during transcription?

RNA polymerase

What is the base pairing rule for RNA?

A-U, C-G

How is RNA different from DNA?

RNA has ribose sugar, uracil, and is single-stranded

What are the three types of RNA?

mRNA, tRNA, rRNA

What is the role of mRNA?

Carries genetic code to ribosome

What is the role of tRNA?

Brings amino acids to ribosome

What is the role of rRNA?

Makes up ribosomes

What is translation?

Process of converting mRNA into a protein

Where does translation occur?

In the cytoplasm at a ribosome

What is a codon?

Three-base sequence on mRNA that codes for an amino acid

How many codons are there?

64

What is the start codon?

AUG (methionine)

What are the stop codons?

UAA, UAG, UGA

What is an anticodon?

Three-base sequence on tRNA that pairs with mRNA codon

What happens at a ribosome during translation?

mRNA is read, tRNA brings amino acids, protein is made

What bond links amino acids in a protein?

Peptide bond

What happens when the ribosome reaches a stop codon?

Translation ends and protein is released

What is the central dogma of biology?

DNA → RNA → Protein

What is a mutation?

Change in the nucleotide sequence of DNA

What causes mutations?

Replication errors, crossing over, mutagens

Do body cell mutations affect offspring?

No

Do sex cell mutations affect offspring?

Yes

Are all mutations harmful?

No - they can be helpful, harmful, or neutral