16. Erwin Chargaff proved that (1)

    1. The concentration of adenine was always about the same as the concentration of thymine.

    2. the concentration of adenine was always about the same as the concentration of guanine.

    3. the concentration of guanine was always about the same as the concentration of thymine.

    4. the concentration of cytosine was always about the same as the concentration of thymine.

16. How does RNA differ from DNA? (1)

    1. RNA contains the sugar ribose instead of deoxyribose.

    2. RNA can move into the cytoplasm, whereas DNA cannot.

    3. RNA contains the nitrogen base uracil instead of thymine.

    4. All of the above

19. Which of the following statements about DNA replication are true? (2)

    1. - DNA replication is the process in which DNA is copied.

    2. DNA replication occurs during the synthesis phase of the eukaryotic cell cycle.

    3. DNA replication begins when an enzyme breaks the hydrogen bonds between complementary bases in DNA.

    4. The two new DNA molecules that result after DNA replication each contain one strand from the parent molecule and one new strand that is complementary to it.

       1. statements 1 and 2

       2. statements 2 and 3

       3. statements 1, 2, and 4

       4. All four statements are true.

19. Which of the following statements about DNA are true? (2)

(1) The DNA double helix consists of two polynucleotide

(2) Each DNA nucleotide consists of a sugar, a phosphate group, and a nitrogen-containing base.

(3) The DNA backbone is composed of the sugar and base of each nucleotide.

1. 1 only

2. 3 only

3. 1 and 2 only

4. 1, 2, and 3

19. The “copy” of genetic instructions which takes the instructions to the cytoplasm is the (1)

    1. messenger RNA.

    2. transfer RNA.

    3. ribosomal RNA.

    4. nuclear RNA.

19. The plasma membrane of a cell consists of two layers of (1)

1. nucleic acids.

2. carbohydrates.

3. phospholipids.

4. lysosomes.

23. Which type of microscope uses electrons to provide a three-dimensional view of the surface of the object? (1)

    1. light microscope

    2. transmission electron microscope

    3. scanning electron microscope

    4. scanning-probe microscope

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Question 2: SHORT QUESTIONS / CALCULATIONS

Match the vocabulary word with the proper definition and place the letter of the vocabulary word in the space provided before the definition.

Definitions (1 each)

__g___2.1 the process in which cells make proteins

_i____2.2 removes introns from mRNA

__c___2.3 the sequence of A, C, G, T (or U) bases in a polynucleotide chain

__e___2.4 complementary to a strand of DNA

__ J___2.5 contains an anticodon that is complementary to the codon for an amino acid

__L___2.6 RNA → Protein

___k__2.7 DNA → RNA

__a___2.8 a group of three nitrogen bases

__b___2.9 regions of mRNA that code for proteins

_d____2.10 regions of mRNA that do not code for proteins

__h___2.11 the way the groups of three bases are divided into codons

_f____2.12 a region of a gene where RNA polymerase binds