4. The first enzymatic step in making a cDNA uses which of the following?
(A) EcoRI nuclease
(B) Taq polymerase
(C) DNA polymerase
(D) RNA polymerase
(E) reverse transcriptase

15. In a field of corn or lettuce on a farm, plants are cultivated with uniform spacing that will maximize plant growth. In natural habitats, however, a uniform pattern of dispersion is much less common. While exceptions do exist, for example in populations of creosote bush in the desert, which of the following best explains why natural populations of plants usually exhibit clumped or random dispersion patterns? (A) Patterns of higher soil moisture, the concentration of soil nutrients, and the distribution of seeds from parent plants may be highly variable. (B) Precipitation across landscapes, especially mountain ranges, is uniform. (C) The competitive interactions between individuals of the same population usually lead to such dispersion patterns. (D) Since nearly all plants are wind-pollinated, the direction of breezes can affect whether plants will produce seeds.

1. Which energy-producing process is thought to have come first during cellular evolution? (A) Photosynthesis (B) Glycolysis (C) Oxidative phosphorylation (D) Proteolysis (E) All of the above originated at the same time.

2. The interaction of the light and heavy chains to form the immunoglobulin molecule is an example of ______ structure. (A) primary (B) secondary (C) tertiary (D) quaternary (E) domain

3. In allosteric regulation, binding of a small regulatory molecule to an enzyme ______ the enzyme activity. (A) inhibits (B) stimulates (C) either stimulates or inhibits (D) neither stimulates nor inhibits (E) both stimulates and inhibits

5. The Arabidopsis genome, like many plant genomes, contains more genes than many animals and this is due largely to ______. (A) gene duplication (B) larger exons (C) larger introns (D) fewer stop codons (E) None of the above

6. The proofreading property of DNA polymerase is due to its ______ activity. (A) 3' to 5' exonuclease (B) 5' to 3' exonuclease (C) excision repair (D) mismatch repair (E) endonuclease

7. Small interfering RNAs repress transcription by ______. (A) binding to and cleaving the gene. (B) binding to and methylating the DNA of the gene. (C) hybridizing with and blocking transcription of a gene. (D) hybridizing with a nascent mRNA and binding a RITS complex, which condenses the chromatin of a gene. (E) All of the above

8. Eukaryotic ribosomes recognize and initially bind to what structure on the mRNA? (A) A Shine-Dalgarno sequence (B) The 7-methylguanosine cap (C) A TATA sequence (D) An AUG initiation codon (E) A CAT sequence

9. The nuclear localization signal is recognized by and binds to which protein in the process of nuclear protein import? (A) Ran (B) Exportin (C) Importin (D) Nucleoporin (E) The outer fibril protein

10. Which of the following is not a contiguous membrane domain? (A) Rough ER (B) Nuclear envelope (C) Smooth ER (D) Transitional ER (E) Secretory granules