46. These are the only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart.
(A) Amphibians
(B) Birds
(C) Fishes
(D) Mammals
(E) Reptiles

42. The seeds of many plant species are dispersed by a harmless temporary attachment to an animal's fur or feathers. This form of dispersal can be classified as (A) ectoparasitism. (B) amensalism. (C) mutualism. (D) pollination. (E) phoresy.

43. Which of these types of islands is predicted to have the lowest number of species? (A) small island near mainland (B) large island near mainland (C)large island far from mainland (D) small island far from mainland (E) the island closest to mainland regardless of size

44. Primary production is generally highest in (A) tundra. (B) desert. (C) wetlands. (D) tropical rain forests. (E) tropical oceans.

45. DNA methylation (A) increases transcription. (B) inhibits transcription. (C)increases crossover events. (D) decreases crossover events. (E) promotes post-translational modification of proteins.

47. The clonal selection theory is an explanation for (A) how a single type of stem cell can produce both red blood cells and white blood cells. (B) how antibody proteins can be molded to fit antigens after the antigen interacts with the antibody-producing type of cell. (C)how an antigen can induce the multiplication of B cells to result in production of high levels of specific antibodies. (D) how HIV can disrupt the immune system. (E) how macrophages can recognize specific T cells and B cells.

48. ________ is a water-soluble hormone derived from the nervous system that regulates blood volume and blood pressure? (A) Antidiuretic hormone (B) Aldosterone (C) Cortisol (D) Oxytocin (E) Adrenocorticotropic hormone

49. Active transcription occurs on (A) centromere (B) telomere (C) cytosome (D) heterochromatin (E) euchromatin

50. Which of the followings is an example of post-transcriptional gene processing? (A) DNA methylation (B) histone acetylation (C) RNA splicing (D) proteasome regulation (E) chromatin modification

1. Which of the following names is correct? (A) iodine trichlorite, ICl3 (B) phosphorus pentoxide, P2O5 (C) chlorous acid, HClO2 (D) lithium hydrogen, LiH (E) calcium(II) oxide, CaO

2. Calculate the pH of a 0.010 M aluminium chloride solution. The Ka value for Al(H2O)63+ is 1.4 × 10-5. (A) pH=1.35 (B) pH=2.38 (C) pH=3.43 (D) pH=4.31 (E) pH=5.36