Unit 5: DNA & Gene Expression Test Review

The backbone of a DNA molecule is made of which two components?

• phosphate molecules and ribose sugars

• deoxyphosphate molecules and ribose sugars

• phosphate molecules and deoxyribose sugars

• deoxyphosphate molecules and deoxyribose sugars

When Susie create a DNA model in her Biology class, it consisted of many nucleotides. The nucleotides are made up of three parts. One of the parts is a sugar molecule. Every strand of DNA contains the same type of sugar. What is the name of the sugar found in a DNA strand?

• Glucose

• Ribose

• Deoxyribose

• Phosphate

When Watson and Crick put together a model of DNA, it was best described as a (an)

• ladder

• X with a centromere in the middle

• strand of beads

• double helix

Erwin Chargaff studied DNA and discovered that a sequence of bases on one strand will determine the bases on the other strand. This rule of complementary base pairs states:

• The number of thymines will always equal cytosines.

• The number of thymines will always equal adenines.

• There are no thymines in a DNA molecule.

• The number of thymines is not significant to the function of the molecule.

Stan and Sue were responsilbe for making a model of DNA in their Biology class. After their model was completed they were asked to replicate their DNA as if it were happening inside an actual cell. When they finished, they ended up with

• two completely different strands of DNA

• two single stranded molecules of DNA

• two identical strands of DNA, each with an original strand and a new strand

• one new strand of DNA and one old strand

All of the following are true about the structure of DNA except

• short strands of DNA are contained in chromosomes located in the cytoplasm

• every DNA nucleotide contains a sugar, a phosphate group, and a nitrogen base

• DNA consists of two strands of nucleotides joined by hydrogen bonds

• the long strands of nucleotides are twisted into a double helix

Watson and Crick built models that demonstrated that

• DNA and RNA have the same structure

• DNA is made of two strands that twist into a double helix

• guanine forms hydrogen bonds with adenine

• thymine forms hydrogen bonds with cytosine

The scientists credited with establishing the structure of DNA are

• Avery and Chargaff

• Hershey and Chase

• Mendel and Griffith

• Watson and Crick

During DNA replication, a complementary strand of DNA is made for each original DNA strand. Thus, if a portion of the original strand is CCTAGCT, then the new strand will be

• TTGCATG

• AAGTATC

• CCTAGCT

• GGATCGA

As Jerry studies the process of DNA replication he knows that before this process can begin the hydrogen bonds holding the nitrogen bases together must be broken by enzymes called

• double helixes

• helicases

• forks

• phages