Biology 9

The process that makes an exact copy of a cell’s DNA is called

• Conservation

• Preservation

• Replication

• Synthesis

What are the main functions of DNA polymerase?

• Breaks hydrogen bonds and expose bases

• Holds DNA strands apart and attract bases

• Zip and unzips the double stranded DNA

• Binds nucleotides and correct base pair errors

Which of the following events occurs directly after a DNA molecule is unzipped?

• Mismatched nucleotide bases are identified and replaced

• Free floating nucleotides pair up with exposed bases

• Identical double stranded DNA molecules are formed

• Enzymes break hydrogen bonds between base pairs

The process of making new DNA molecules is semi conservative, this means that every newDNA molecule is composed of

• Two completely identical strands of DNA

• One original and one new strand of DNA

• One strand of DNA and one strand of RNA

• Two strands that mix original and new DNA

When new DNA molecules are formed, almost all errors are detected and fixed by

• The correct nucleotide

• The sugar - phosphate backbone

• DNA polymerase

• One DNA strand

The four types of nucleotides that make up DNA are named for their

• Hydrogen bonds

• Nitrogen containing bases

• Phosphate groups

• Ring shaped sugars

After examining the DNA of different organisms, which of the following did Erwin Chargaff conclude about the four bases?

• A=T and C=G

• A=C and G=T

• A=C and G=T

• A+T =C+ G

Which of the following DNA sequences is complementary to the base sequence ACCGTAT ?

• GTTACGC

• UCCGTAT

• TGGCATA

• CAATGCG

Combining the work of other scientists with their own research, watson and crick discovered that two strands of DNA join together to form a(n)

• Nucleotide

• X in a circle

• Double helix

• Covalent bond

What holds base pair together?

• Hydrogen bonds

• Sugar-phosphate backbones

• Pairs of double ringed nucleotides

• Nitrogen carbon bonds