29. What substance(s) can affect the concentration of calcium ions inside the cell, an important secondary messenger?
(A) Phosphatidylcholine and phospholipase A
(B) Phosphatidylcholine and phospholipase C
(C) Phosphatidylinositol and phospholipase A
(D) Phosphatidylinositol and phospholipase C
(E) Calmodulin

25. Which step of the mitochondrial electron transport chain does rotenone inhibit? (A) NADH → coenzyme Q (B) Cyt b → Cyt c1 (C) Cyt c1 → Cyt c (D) Cyt c → Cyt (a+a3) (E) Cyt c → O2

26. Regarding the chemiosmotic theory of the respiratory chain, which statement is TRUE? (A) Oxidative phosphorylation occurs in the outer mitochondrial membrane. (B) The proton (H+ ) concentration is the same on both sides of the inner mitochondrial membrane. (C) ATP synthase plays no role in the chemiosmotic theory. (D) Mitochondrial inner memebrane is permeable for proton. (E) ATP synthesis is related to proton-motive force.

27. Which of the following sets of amino acids are directly involved in the biosynthesis of creatine? (A) tyrosine, glycine, and glutamine (B) glutamate, cysteine, and glycine (C) glycine, arginine, and methionine (D) aspartate, glycine, and cysteine (E) proline, alanine, and leucine

28. Hydropathy plot is commonly used for ______. (A) predicting the quaternary structure of membrane proteins (B) measuring the water content of native proteins (C) estimating the actual molecular weight of membrane proteins (D) predicting whether a known protein amino acid sequence contains a membrane-spanning segment (E) analyzing protein secondary structure

30. Which statement is TRUE? (A) A higher Km value indicates a higher substrate specificity. (B) A higher Km value indicates a higher substrate affinity. (C) The unit for Km is M-1 s -1 . (D) kcat is the specificity constant. (E) kcat/Km is a measure of enzyme efficiency.

31. Which description about interaction between species is NOT true? (A) Predation: An individual of one species, the predator, kills and eats an individual of the other, the prey. (B) Parasitism: The parasite obtains its nourishment from a second organism, its host. (C) Competition: Indivisuals of different species each use a limited resourse, reducing the survival or reproductin of both individuals. (D) Commensalism: Members of both species benefit from the interaction. (E) Herbivory: An herbivore eats part of a plant or alga.

32. Fungal cells can reproduce asexually by undergoing mitosis, followed by cytokinesis. Many fungi can also reproduce sexually by undergoing ______. (A) cytokinesis followed by karyokinesis (B) binary fission followed by cytokinesis (C) plasmolysis followed by karyotyping (D) plasmogamy followed by karyogamy (E) sporogenesis followed by gametogenesis

33. Which is a TRUE statement concerning genetic variation? (A) It is created by the direct action of natural selection. (B) It arises in response to changes in the environment. (C) It must be present in a population before natural selection can act upon the population. (D) It tends to be reduced by the processes involved when diploid organisms produce gametes. (E) A population that has a higher average heterozygosity has less genetic variation than one with a larger average heterozygosity.

34. Why do RNA viruses appear to have higher rates of mutation? (A) RNA viruses are more sensitive to mutagens. (B) RNA viruses can incorporate a variety of nonstandard bases. (C) RNA viruses replicate faster. (D) Replication of their genomes does not involve the proofreading steps of DNA replication. (E) RNA nucleotides are more unstable than DNA nucleotides.

35. To prevent irreversible tragedies, the CDC urges the public not to use blood donation as a means of Human immunodeficiency virus (HIV) testing, as there is a period for HIV infection. (A) prophase (B) infectious (C) latency (D) anaphase (E) telophase