Biology Multiple Choice Questions on “Plants – Means of Transport”.
1. Diffusion is a common process in fluids, but diffusion in solids rather than of solids is more likely.
a) True
b) False
Answer: a
Clarification: In case of solids, the molecules of one substance do not get inside the intercellular spaces of another substance as they are rigid in nature. But there are intermolecular spaces in between molecules of solids, however small they may be. So, diffusion of fluids in that space is very much possible.
2. Which of the following does not affect the rate of diffusion?
a) Temperature
b) Pressure
c) ATP available
d) Concentration gradient
Answer: c
Clarification: Diffusion is a passive process and it doesn’t require energy in the form of ATP. Temperature, Pressure and Concentration gradient do affect the rate of diffusion to varying degrees.
3. Statement A: Active transport of molecules is an uphill movement.
Statement B: Simple diffusion is non-selective process.
a) Both the statements are true
b) Both the statements are false
c) Statement A is true but Statement B is false
d) Statement B is true but Statement A is false
Answer: a
Clarification: Active transport of molecules is an uphill movement from low concentration to high concentration. Simple diffusion is a downhill movement from high concentration to low concentration.
4. Which among the following is not the property of proteins present in the membrane that support facilitated diffusion?
a) Not liable to saturate
b) Response to inhibitors
c) Regulated by hormones
d) Highly selective
Answer: a
Clarification: Proteins are liable to saturate, respond to inhibitors, under hormonal regulation and highly selective, thus, are responsible for facilitated diffusion.
5. Diffusion is mainly a ________
a) mechanical process
b) physical process
c) chemical process
d) biological process
Answer: b
Clarification: Diffusion is a physical process. It has applications in mechanical, chemical and biological processes such as in fluid mechanics, solid state and transport of substances.
6. Diffusion is fastest in ________
a) carbohydrates
b) proteins
c) lipids
d) vitamins
Answer: c
Clarification: Diffusion is faster in substances with molecules having hydrophobic moiety. Among the following, lipids have hydrophobic moiety whereas carbohydrates, proteins and vitamins have hydrophilic moiety.
7. Concentration gradient is a mandatory condition for diffusion of substances irrespective of the process involved.
a) True
b) False
Answer: a
Clarification: All the processes require a redox potential in order to transport substances from one place to another. A concentration gradient is an essential condition for the transport of molecules of substances to occur.
8. Porins are not present in _____
a) plastids
b) bacteria
c) mitochondria
d) golgi complex
Answer: d
Clarification: Plastids, mitochondria and some bacteria possess porins but they’re absent in golgi complex.
9. Which kind of facilitated diffusion is depicted in the picture given below?
a) Uniport
b) Symport
c) Antiport
d) Export
Answer: c
Clarification: In antiport, carrier proteins allow diffusion of molecules in opposite direction. Symport is the diffusion two molecules in the same direction. In uniport, there is transport of only one molecule at a time. Export is the movement of molecules out of a source.
10. Statement A: Pumps are proteins that use energy to carry substances across the cell membrane.
Statement B: They transport substances from high concentration to low concentration.
a) Both the statements are true
b) Both the statements are false
c) Statement A is true but Statement B is false
d) Statement B is true but Statement A is false
Answer: c
Clarification: Active transport is carried out by pump proteins. Pumps are proteins that use energy to carry substances across the cell membrane. They transport substances from high concentration to low concentration with the use of ATP.