Unit 4: Genetics

In humans, where does DNA replication take place?

• Cytoplasm

• Rough ER

• Mitochondria

• Nucleus

A DNA molecule could contain the following molecules

• deoxyribose, cytosine, and a lipid

• deoxyribose, thymine, and a phosphate group

• ribose, uracil, and a polypeptide

• ribose, adenine, and thymine

Which of the following nucleic acids contains thymine?

• DNA only

• tRNA

• mRNA

• all of these

DNA is a polymer consisting of monomers known as ___.

• peptides

• nucleotides

• amino acids

• phosphates

In nucleotides, the letters A, G, C, and T represent ____.

• phosphate groups

• sugars

• nitrogenous bases

• proteins

RNA from a chipmunk is compared to RNA from a worm. Both will contain the ____.

• sugar ribose and the base uracil.

• sugar deoxyribose and the base uracil.

• sugar deoxyribose and the base thymine

• sugar ribose and the base thymine.

The cellular process of creating two new DNA molecules from one original copy is called replication. Which

statement is the BEST description of this process?

• DNA opens up and RNA copies it.

• DNA opens up and completely unwinds to make two new molecules.

• DNA opens up and each strand is used as a template for making a new strand.

• RNA opens up the DNA and uses each strand as a template for a new strand.

Base your answer to this question on the diagram shown AND on your knowledge of

biology. Structures 3 and 4 are held together by ____.

• weak peptide bonds

• weak hydrogen bonds

• strong hydrogen bonds

• strong peptide bonds

A scientist is doing an experiment to identify different molecules. Some components of these molecules are listed in this table. Which of the four molecules is the DNA?

• Molecule 1

• Molecule 2

• Molecule 3

• Molecule 4

If a portion of a messenger RNA molecule contains the base sequence A-A-U, then the corresponding anti-codon on the tRNA base sequence is _______.

• A-A-U

• G-G-T

• T-T-A

• U-U-A