DNA Test Review

If DNA molecule contains 24% cytosine, how much adenine will that DNA molecule contain?

• 24%

• 26%

• 48%

• 52%

During DNA replication, what is happening at step 2?

• The covalent bonds between the sugar and phosphate groups are broken by DNA Helicase.

• The hydrogen bonds between base pairs of nitrogenous bases are broken by DNA Helicase.

• The hydrogen bonds between base pairs of nitrogenous bases are broken by DNA polymerase.

• The covalent bonds between the sugar and phosphate groups are broken by DNA Polymerase.

Tags

NGSS.HS-LS1-1

A DNA strand is undergoing replication and contains the bases TACGTT. Which complementary strand would be produced?

• AUC GAA

• ATC GAA

• ATG CAA

• AUC GTT

Which statement about the structure of DNA is true? CHOOSE 3.

• • Long strands of DNA are twisted in the form of a double helix.

• • DNA contains four different nitrogen bases including adenine, guanine, cytosine, and uracil.

• • DNA is made of linked nucleotides which are each made of a sugar, a phosphate and a nitrogen base.

• • DNA consists of two strands joined together by complementary base pairing.

Use the diagram to help you answer the question.

The graph shows the effect of pH on the rate of reaction for two digestive enzymes: pepsin and trypsin.

What is the best conclusion from the graph?

• • Pepsin functions best in an acidic environment.

• • Trypsin functions best in a basic environment.

• • Both pepsin and trypsin function best in a basic environment.

• • Both pepsin and trypsin function best in an acidic environment.

Tags

NGSS.MS-PS1-2

Which of these sequences correctly describes how DNA is copied?

• •  Bonding of bases - separation of strands - base pairing

• • Separation of strands - bonding of bases - base pairing

• • Bonding of bases - base pairing - separation of strands

• • Separation of strands - base pairing - bonding of bases

DNA and RNA contain different bases. What of the following bases is only found in RNA only?

• cytosine

• thymine

• guanine

• uracil

Estella spilled tomato sauce on her shirt. When she washed her shirt, she noticed that the detergent she used contained enzymes. Enzymes are added to detergents to break down proteins from food and other substances that may stain clothing. Which would most likely inhibit the ability of the enzymes to remove the stain on her shirt?

• •  the amount of dissolved minerals in the water

• the type of fibers from which her shirt was made

• •  the temperature of the water

• • he fragrances in the detergent

Tags

NGSS.HS-PS1-5

Enzymes influence chemical reactions in living systems by

• • Combining with excess hydrogen to form gaseous wastes

• • Affecting the rate (speed) at which reactions occur

• • Providing the substrate required for the reaction to occur

• • Absorbing water released when polymers are formed

Tags

NGSS.HS-LS2-3

Illustration 1 shows sugar that has formed a bond by the action of an enzyme. Illustration 2 shows the enzyme, and Illustration 3 shows the enzyme after the addition of heat.

How does the addition of heat affect the ability of an enzyme to help the sugar molecules form a bond?

• • Heat allows the sugar molecules to bond more quickly.

• • Heat provides places on the enzyme for other molecules to bond.

• • Heat changes the enzyme so that the sugar molecules can no longer bond.

• • Heat does not affect the enzyme or substrate.

Tags

NGSS.HS-PS1-5