26. _____ is NOT a second messenger.
(A) Ca²⁺
(B) Nitric oxide
(C) Phosphatidylinositol 4, 5-bisphosphate
(D) Sphingomyelin
(E) ATP

22. Which of the following is peptide hormone? (A) thyroxin (B) epinephrine (C) antidiuretic hormone (D) progesterone (E) cortisone

23. The translation terminates in which of the following condition? ① ribosome reaches the end of mRNA② ribosome reaches the stop codon③ deficient in certain amino acid ④ no aminoacyl-tRNA enters ribosome ⑤ polypeptide folds into protein (A) ① ③(B) ②④ (C) ① ② ③ (D) ③ ④ (E) ② ③ ④

24. Cancer types can be classified according to the origin of cells or tissues. Which of the following statements is FALSE? (A) Cancers of the leukemia cells are called lymphomas. (B) Cancers of the epithelial cells are called carcinomas. (C) Cancers of the glandular cells are called adenocarcinoma. (D) Cancers of the connective tissue are called sarcomas. (E) Cancers of the glial cells are called gliomas.

25. Which of the following RNAs works in RNA splicing? (A) rRNA (B) tRNA (C) snRNA (D) miRNA (E) mRNA

27. Which of the following statements is FALSE? (A) The sex determined in most ants and bees is by the Z-W system. (B) Any gene located on a sex chromosome is called a sex-linked gene. (C) Nondisjunction occurs when members of a chromosome pair fail to separate. (D) The impact of a single gene on more than one character is called pleiotropy. (E) Linked genes generally do not follow the laws of independent assortment.

28. Which of the following functional groups participate in chromatin-mediated gene expression? (A) OH (B) COOH (C) CH 3(D) NH2 (E) CO

29. The eukaryotic DNA replication does NOT contain (A) ligase (B) DNA polymerase (C) helicase (D) topoisomerase (E) gyrase

30. Which of the following statements about signal transduction is FALSE ? (A) Signal transduction only can start with a signal to a membrane receptor, and ends with a change in cell function. (B) The signal must be amplified in a cascade manner within the cells. (C) Signal transduction can link with all cellular responses respond to external stimuli. (D) Signal transduction closely links with gene expression to alter metabolism. (E) Signal transduction is largely carried out by second messenger molecules.

31. Which of the following statements is FALSE? (A) The cells of the mucous membrane lining human air tubes carry cilia that sweep mucus up and out of the respiratory system. (B) Adipose tissue is a type of connective tissue. (C) Epithelial tissues cover both external and internal body surfaces. (D) The most common type of connective tissue in the human body is fibrous connective tissue. (E) Connective tissue is different from the other major tissue types in that the cells are sparsely scattered through a nonliving matrix.

32. Which of the following structures does NOT belong to the human lymphatic system? (A) tonsils (B) thymus (C) pancreas (D) appendix (E) bone marrow