24. High levels of which of the following hormones can suppress the body's immune system?

(A) glucagon

(B) mineralocorticoids

(C) glucocorticoids

(D) antidiuretic hormone

20. Which of the following is the best definition of autoimmune disease? (A) a condition in which B cells and T cells respond independently to antigens and do not interact correctly (B) a condition in which the adaptive immune system fails to recognize the second infection by the same antigen (C) a condition in which self molecules are treated as nonself (D) a condition in which the immune system creates random antibodies without being triggered by an antigen

21. Which of the following correctly identify which organs develop from different embryonic tissue layers in a frog? | Endoderm | Mesoderm | Ectoderm | | :---------- | :--------- | :---------- | | (A) Brain | Heart | Epidermis | | (B) Liver | Heart | Brain | | (C) Notochord | Liver | Eye lens | | (D) Liver | Nerves | Muscles |

22. Which of the following is an endocrine gland that raises blood calcium levels? (A) parathyroid (B) thyroid gland (C) pituitary gland (D) testes

23. An excess of T3 and T4 in the blood is hyperthyroidism, which in its most common form is called (A) goiter. (B) sterility. (C) Graves' disease. (D) botulism.

25. After being produced in the testes, sperm mature further in a structure called the (A) vas deferens. (B) epididymis. (C) prostate. (D) seminal vesicle.

26. Water's unique properties for the chemical basis of life are primarily a consequence of its: (A) highly stable covalent bonds. (B) existence as individual atoms in organisms. (C) polarity and hydrogen bonding. (D) role in preventing elements from combining. (E) exceptional heat resistance due to strong ionic bonds.

27. Which statement accurately reflects a fundamental concept of cells? (A) Carbon compounds are essential building blocks due to limited bonding. (B) Carbohydrates primarily provide long-term energy storage. (C) Lipids are hydrophilic, serving mainly as immediate fuel. (D) Carbohydrates are a cell's primary fuel source and important building materials. (E) Biomolecule functions are determined by nitrogen and phosphorus.

28. Which statement accurately describes a fundamental concept about cell structure and function? (A) Genetic instructions are in the nucleus, but ribosomes are not involved in protein synthesis. (B) Microscopes are essential but strictly limited to non-living cells. (C) The endomembrane system generates energy exclusively via oxidative phosphorylation. (D) Genetic instructions in the nucleus are carried out by ribosomes for protein synthesis. (E) Ribosomes are membrane-bound organelles managing material distribution.

29. A unique adaptation found only in angiosperms is: (A) showy cones for animal pollination. (B) an ovary enclosing ovules that mature into a fruit. (C) spores released to develop into free-living gametophytes. (D) seeds produced on cone scales. (E) lack of enclosed seeds at maturity.

30. In gymnosperm reproduction, the male gametophyte is: (A) a pollen grain enclosed within a tough wall. (B) where sperm fertilizes eggs within the female structure. (C) a free-living gametophyte developed from released spores. (D) a nucleus released freely into the ovule without a pollen tube. (E) an ovule maturing into a fruit after fertilization.