27. Which of the following is NOT true?
(A) Alpha-amanitin inhibits the activity of all three RNA polymerases of eukaryotes by interacting with a bridge helix in the enzymes.
(B) Chloramphenicol blocks translation by inhibiting the peptidyl transferase activity of ribosome.
(C) Cycloheximide blocks translation by interfering with the translocation step in protein synthesis.
(D) Cytochalasin B inhibits cytoplasmic division by blocking the formation of contractile microfilaments.
(E) None of the above.

23. Nerve impulses are normally carried toward a neuron cell body by the neuron's (A) Synaptic cleft (B) Axon (C) Hormones (D) Dendrites

24. In sensory neurons, stimuli are received by the (A) Axons (B) Dendrites (C) Cell body (D) Myelin

25. Ovulation is caused by the hormone (A) FSH (B) Progesterone (C) Oxytocin (D) Estrogen (E) Luteinizing Hormone

26. Which of the following statements is NOT true? (A) Evolutionary theory holds that all of life has a common ancestor. (B) Cladistics involves the identification of evolutionary branches that consists of an ancestral species and all its descendants. (C) Parsimony is the search for the least complex explanation for an observed phenomenon. (D) Comparisons of molecules that evolve very fast would help to determine the phylogenetic relationships of fungi, plants and animals. (E) Phylogenies are based on homologies in fossils and living organisms.

28. "GGATGGTCTT" is the partial sequence of gene X. What would be the sequence of the mRNA transcribed from this gene? (A) UUCUGGUAGG (B) AAGACCAUCC (C) GGAUGGUCUU (D) CCUACCAGAA (E) None of the above.

29. In _____ reproductive isolation develops and new species arise without geographic separation. (A) Adaptive radiation (B) Adaptive speciation (C) Allopatric speciation (D) Sympatric speciation (E) Tempo of speciation

30. Which of the following enzymes may be used to detect single nucleotide mutation? (A) DNase I (B) DNA ligase (C) Exonuclease (D) Integrase (E) Restriction enzyme

31. For a population to be in Hardy-Weinberg equilibrium, it must satisfy the following conditions except: (A) The population is very large. (B) Mating is random and all individuals are equal in reproductive success. (C) Lack of gene flow. (D) Mutations do not alter the gene pool. (E) None of the above.

32. Which of the following plays an essential role in sex determination of Drosophila melanogaster? (A) Alternative spicing (B) cis splicing (C) RNA editing (D) Self splicing (E) trans splicing

33. The plasmid vector most commonly used to introduce genes into plant cells is: (A) the CoEl plasmid (B) the Ti plasmid (C) the R1 plasmid (D) the Ri plasmid (E) Plasmid pUC19