175.Người đi xe đạp ra hiệu sắp rẽ trái
(A)O
(B)X

171.Rẽ phải(A)O(B)X

172.Giảm tốc độ tạm dừng(A)O(B)X

173.Nhường cho xe sau vượt(A)O(B)X

174.Đề phòng Động vật(A)O(B)X

176.Người đi xe đạp ra hiệu sắp rẽ phải(A)O(B)X

1. ______ is the major constituent of cellular membrane. (A)triglyceride(B) phospholipid (C)steroids (D) fatty acid (E)cholesterol

2. Amino acids can be distinguished from one another by __________.(A) the number of R groups found on the amino acid molecules.(B) the chemical properties of their R groups. (C)the type of bond between the R group and the rest of the amino acid molecule.(D) the chemical properties of their amino and carboxyl groups. (E)All of the choices are correct.

3. Every subunit (nucleotide) of a polynucleotide contains ______ negative charge(s). (A)0(B) 1 (C)2 (D) 3 (E)4

4. Considering the following statements about active transport, which of these statements are true? I. Facilitated diffusion is a special kind of active transport that does not require energy. II. Active transport requires energy, usually in the form of ATP hydrolysis. III. Active transport moves substances down their concentration gradients. IV. All proteins involved in active transport are carrier proteins V. Ion channels facilitate the active transport of ions (A)II and IV(B) I, II, III and IV (C)II, IV and V (D) I, II and IV (E)All

5. How do the reaction centers of photosystem I, and II differ? (A)chlorophyll a is found in photosystem I, and chlorophyll b in photosystem II.(B) They preferentially absorb slightly different wavelengths of light. (C)One is located in the thylakoid membrane, and the other in the stroma. (D) Only photosystem I is found in the thylakoid membranes. (E)None of the above.