Honors Bio Unit 4 Test 1 (4.1-4.2)

A DNA nucleotide could contain which 3 molecules: ​ ​ ​

• deoxyribose, thymine, phosphate group

• ribose, thymine, phosphate group

• deoxyribose, uracil, phosphate group

• ribose, uracil, polypeptide

Which of the following nucleic acids contains thymine?

• DNA only

• RNA only

• mRNA only

• tRNA only

Answer explanation

The thymine base is found only in DNA not RNA

What is the central dogma?

• DNA replication

• DNA-->

  RNA-->Protein

• RNA-->

  DNA-->Protein

• Transcription

In humans, where does DNA replication take place?

• nucleus

• cytoplasm

• ribosomes

• vacuole

Answer explanation

DNA is stored in the nucleus, so DNA replication must take place in the nucleus.

DNA is a polymer consisting of monomers known as

• peptides

• polypeptides

• nucleotides

• phosphates

Answer explanation

the monomer (single molecule form) of DNA is nucleotides. The polymer (multiple monomers linked together) of DNA is nucleic acids

Why must our cells transcribe DNA into mRNA before proteins can be made?

• DNA replication allows for mRNA to synthesize proteins in the nucleus

• mRNA is too large to leave the nucleus, but DNA is smaller and able to attach to ribosomes and make proteins

• DNA is too large to leave the nucleus, but mRNA is smaller and can leave the nucleus and attach to ribosomes to synthesize proteins

• mRNA carries instructions for making DNA which can be translated into proteins

Nitrogenous bases are held together by what kind of bonds?

Answer explanation

Weak hydrogen bonds hold the nitrogen bases together so they are easily broken apart for replication or transcription.

The sequence of​ ______ in a DNA molecule determines the protein that will be produced.

• nitrogen bases

• proteins

• sugars

• guanines

Which statement best describes DNA replication

• RNA opens up DNA and uses each strand as a template to make a new strand

• DNA opens up and each strand is used as a template to make a new strand

• DNA opens up and completely unwinds to make 2 new nucleotides

• DNA opens up and RNA copies it

In nucleotides, the letters A, T, C and G represent what?

• types of sugars

• types of oxygen

• nitrogen bases

• phosphate bases