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请告诉我答案和解释,谢谢 ^^
biology
1. facilitated diffusion required energy in form of ATP?
2. facilitated diffusion occurs when molecules move from a region of high concentration to low concentration?
3. active transport occurs in almost all animal and plant cell?
4.plant cell membrane consist of phospholipids and proteins only,没有cellulose?
5. increase in temperature 会 increase the rate of active transport?
6.which is involved in facilitated difffusion?
A. phospholipid
B. polysaccharide
C. polynucleotide
D. polypeptide
(这四个到底是什么来的?)
7. which statement best describe facilitated diffusion?
A. the passive movement of a particle across a cell membrane through a channel protein
B. the movement of a particle down a concentrared gradient aided by protein pumps
(我选B,可是答案是A,为什么?)
8. which is an example of active transport?
A. movement of nitrate ions into root hair cells
B. movement of sodium ions in blood plasma
9. which part of the cell are directly involved with the absorption of digested materials into the blood?
I. plasma membrane
II.cytoplasm
III. mitochondria
IV. nucleus
A. I and II
B. II and III
C. I, II and III
D. all
10. 我要考试了,要背cellular component? 背function only?
11.
normal concentration of sodium ions in red blood cell = 44
normal concentration of pottasium ions in red blood cell=147
normal concentration of sodium ions in blood plasma = 131
normal concentration of pottasium ions in blood plasma =22
which of the statement is a suitable conclusion of the above information?
A. sodium ion is actively transported out of the cell
B. sodium ion is transported out of the cell by diffusion, but potassium does not move
C. sodium moves into the red blood cells by diffusion and then potassium moves out by diffusion
(答案是A? 为什么?)
physic
1. which is not derived from time and length only?
A. density
B. momentum
(两个都对?)
2. weight 是 mass x (length / time square)?
3. density of mercury is 13.6g cm^-3
what is its density in kgm^-3?
A. 13.6 x 10^-3 kgm^-3
B. 13.6 x 10^3 kgm^-3
4. which is correct?
A. 1000 mm^3 = 10^-6 m^3
B. 1000 mm^3 = 10^6 m^3
(答案是A 为什么不是B? ) |
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