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

13. Which of the following statements correctly describes the colonization of terrestrial habitats by plants? (A) It occurred in conjunction with insects that pollinated them. (B) It occurred in conjunction with fungi that helped provide them with nutrients from the soil. (C) It helped them to escape abundant herbivores in the oceans. (D) It occurred only about 150 million years ago.

14. Which of the following functions is an advantage of seeds compared to spores? (A) using wind as a dispersal agent (B) containing a nutrient store for a developing sporophyte (C) relying on animals for pollination (D) providing nutrition for animals

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.

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

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

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