6. About digestion, which of the following statement is TRUE?
(A) Protein digestion occurs only in the stomach
(B) Most digestion occurs in the duodenum, where acid chyme from the stomach mixes with digestive enzymes from the pancreas, liver, gallbladder, and the small intestine itself
(C) Polysaccharides digestion starts from small intestine with enzymes from pancreas
(D) Bile is made in the pancreas and stored in the gallbladder

2. In a natural community, the primary consumer is? (A) Carnivores (B) Herbivores (C) Detritivores (D) Decomposers

3. Which of the following statement about enzyme is NOT TRUE? (A) All enzymes' are proteins (B) The active site is the region where the substrate binds (C) Each enzyme has an optimal temperature and pH in which it can function (D) Optimal conditions usually favor the most stable and active conformation for the enzyme molecule

4. What is the central role of helper 'T cells? (A) Helper T cells are the only immune cell type that can produce immunological memory (B) Activated helper T cells release perforin that make pores in the target cell's membrane and enzymes promoting apoptosis leading to cell death (C) Helper T cells can be activated through innate immune response by antigen- presenting cells such as macrophages and dendritic cells, setting stage for the adaptive immune response (D) Activated helper T cells-Lan produce antibodies

5. Which of the following statements about excretory system is NOT TRUE? (A) Nephron is the functional unit of kidney (B) The nephron consists of a single long tubule and a ball of capillaries called glomerulus. Filtration occurs as blood pressure forces fluid from the blood in the glomerulus into the lumen of Bowman's capsule (C) Filtration of small molecules passes through three regions of the nephron: the proximal tubule, the loop of Henle, and the distal tubule, which are all permeable to salt but not to water (D) The controlled movement of ions (such as) in the proximal and distal tubules keep the constant pH in the body fluid

7. Which of the following statement is TRUE about respiration? (A) Alveoli is the place where gas exchange occurs (B) In the capillaries of alveoli, CO2 diffuses into the blood and O2 diffuses into the (C) During inhalation, lung volume increases as the rib muscle contracts and diaphragm relaxes (D) The breathing control center is located in the hypothalamus

8. Thomas Hunt Morgan's choice of Drosophila melanogaster (fruit fly) has been proven to be useful even today. Which of the following is the most important character that makes fy one of the most useful and powerful model organisms in research? (A) They have compound eyes (B) They have large and transparent embryos that can be easily studied (C) They have genome that is more than 90% similar to the human beings (D) They have short life cycle with large number of offspring

9. Which of the following is the most important factor that determine the resolution of a light microscope? (A) Magnification (B) The wavelength of light (C) Contrast (D) Price

10. Which of the following statement about anacrobic and aerobic respirations is NOT TRUE? (A) Both use glycolysis (B) Both use NAD+ as electron carrier (C) Both use oxygen as final electron acceptor (D) Aerobic respiration produces about 30-32 ATP, whereas anaerobic respiration produces 2 ATP

11. About genetic mutation, which of the following statement is TRUE? (A) Silent mutations usually do not have observable effects on phenotypes because they are in-frame mutations (B) Missense mutations change a codon into a stop codon leading to a truncated protein (C) Nonsense mutation is a point mutation in which a single nucleotide change resulted in a change in an amino acid (D) Insertions and deletions are additions or losses of nucleotides in a gene that usually alter the reading frame producing frame-shifted mutations

12. Lipid-soluble signaling molecules, such as aldosterone, can diffuse across the cell membranes but affect only target cells because? (A) Only target cells have responsive DNA segments (B) Intracellular receptors are present only in target cells (C) Only target cells have enzymnes that convert aldosterone to active form (D) Aldosterone-responsive genes are only present in the target cells