39 Which of the following would you expect to be a problem for someone with nonfunctional chloride channeling?
(A) inadequate secretion of mucus
(B) buildup of excessive secretions in organs such as lungs
(C) buildup of excessive secretions in glands such as the pancreas
(D) sweat that includes no NaCl
(E) mental retardation due to low salt levels in brain tissue

35 Within a cell, the amount of protein made using a given mRNA molecule depends partly on (A) the rate at which the mRNA is degraded. (B) the number of introns present in the mRNA. (C) the types of ribosomes present in the cytoplasm. (D) the degree of histone acetylation (E) the degree of DNA methylation. 

36. Phylogenetic trees constructed from evidence from molecular systematics are based on similarities in________. (A) phenotypes (B) morphology (C) mutations to homologous genes (D) the pattern of embryological development (E) biochemical pathways

37. Imprinting has a great impact on normal mammalian development, fetal growth, metabolism and adult behavior. The current molecular explanation for imprinting in mammals involves differential of various DNA regions. (A) Mutations (B) Phosphorylation (C) Dephosphorylation (D) Methylation (E) Transcription

38. CRISPR-Cas9 is adapted from a naturally occurring genome editing system that bacteria use as an immune defense. Which of the following characteristics makes the CRISPR-Cas9 system an efficient way to generate knockout cell lines? (A) It precisely cuts DNA. (B) It removes random DNA bases. (C) It forms a complex with proteins. (D) It applies to both in prokaryotes and eukaryotes. (E) Its function is regulated by complementary guide RNAs.

40. Plants often use changes in day length (photoperiod) to trigger events such as dormancy and flowering. It is logical that plants have evolved this mechanism because photoperiod changes (A) are more predictable than air temperature changes. (B) alter the amount of energy available to the plant. (C) are modified by soil temperature changes. (D) can reset the biological clock. (E) are correlated with moisture availability.

41.Which description of the lateral line system is false? (A) The lateral line system is found in amphibian larvae and fishes. (B) The lateral line system in fish can reflect pressure waves and low-frequency vibrations. (C) The lateral line system consists of hair cells within a longitudinal canal in the fish's skin. (D) The hair cells in the lateral line system are innervated by motor neurons that transmit impulses to the brain. (E) The hair cells' surface processes project into a gelatinous membrane called a cupula.

43. Plant cells and animal cells both evolve specialized conduits that directly connect the cytoplasm of two cells. What are they? (A) plasmodesmata in plant cells, desmotubules in animal cells (B) desmotubules in plant cells, plasmodesmata in animal cells (C) gap junctions in plants cells, plasmodesmata in animal cells (D) plasmodesmata in plant cells, gap junctions in animal cells (E) gap junctions in plant cells, desmotubule in animal cells

44.In plants, the climacteric is a stage of fruit ripening associated with increased production of which plant hormone? (A) auxin (B) abscisic acid (C) cytokinin (D) ethylene (E) Gibberellin

45. In humans, ABO blood types refer to glycoproteins in the membranes of red blood cells. There are three alleles for this autosomal gene: IA, IB, and i. The LA allele codes for the A glycoprotein, The IB allele codes for the B glycoprotein, and the i allele doesn't code for any membrane glycoprotein. IA and IB are codominant, and i is recessive to both IA and IB. People with type A blood have the genotypes IAIA or IAi, people with type B blood are IBIB or IBi, people with type AB blood are IAIB, and people with type O blood are it. If a woman with type B blood marries a man with type A blood, which of the following blood types could their children possibly have? (A) A and B (B) AB and O (C) A, B, and AB (D) A, B, and O (E) A, B, AB, and O

46. How does the enzyme telomerase meet the challenge of replicating the ends of linear chromosomes? (A) It adds numerous GC pairs, which resist hydrolysis and maintain chromosome integrity. (B) It catalyzes the shortening of telomeres, compensating for the elongation that could occur during replication without telomerase activity. (C) It adds a single 5' cap structure that resists degradation by nucleases. (D) It is a reverse transcriptase that carries its own RNA molecule that works as a template to lengthen telomeres. (E) It causes specific double-strand DNA breaks that result in blunt ends on both strands.