Plant Physiology Quiz

What is plant physiology a study of?

The evolution of plant species over time
The structure of plant cells and tissues
How plants grow, develop, and function in their environments (correct)
The way plants respond to their environment

What is essential for photosynthesis in plants?

Carbon dioxide
Oxygen
Water (correct)
Nitrogen

What is the role of water in plants?

To regulate temperature
To provide structural support
To facilitate photosynthesis
To prevent leaf desiccation (correct)

What do plants need to prevent dehydration?

Less water loss (C) Signup and view all the answers

What is essential for plant survival?

All of the above (D) Signup and view all the answers

What is the relationship between structure and function in plants?

They represent different frames of reference of a biological unity (A) Signup and view all the answers

What is the primary mechanism of transport in cells at a small scale?

Diffusion (C) Signup and view all the answers

What is the term for the diffusion of water across a selectively permeable barrier?

Osmosis (D) Signup and view all the answers

What is the driving force behind the movement of molecules during diffusion?

Random thermal agitation (C) Signup and view all the answers

What is the result of the random movements of molecules during diffusion?

Net movement from high to low concentration (B) Signup and view all the answers

What determines the number of molecules crossing an imaginary plane during diffusion?

The number of molecules on either side (A) Signup and view all the answers

What is the tallest height that trees can transport water, due to cohesion and adhesion?

100 m (D) Signup and view all the answers

What is the stored free energy in the form of the H+ gradient?

Electrochemical potential for H+ (B) Signup and view all the answers

What is the physical property that predicts the direction in which water will flow?

Water potential (B) Signup and view all the answers

What is the unit of pressure used to measure water potential?

Megapascal (MPa) (C) Signup and view all the answers

What is the water potential of pure water in a container open to the atmosphere under standard conditions?

0 MPa (B) Signup and view all the answers

What occurs when a substance is more concentrated on one side of a membrane than the other?

The substance diffuses across the membrane down its concentration gradient. (D) Signup and view all the answers

What is the purpose of the proton motive force generated by electrogenic H+ transport?

To drive the transport of other substances against their gradient of electrochemical potentials (D) Signup and view all the answers

What is the term for the absorption or loss of water by a cell?

Osmosis (D) Signup and view all the answers

What is required for active transport to occur?

Energy from the cell (B) Signup and view all the answers

What is the function of transport proteins in biological membranes?

To facilitate the passage of selected ions and polar molecules (B) Signup and view all the answers

What determines the transport specificity of channels?

The size of the pore and the density of surface charges on its interior lining (C) Signup and view all the answers

What is the function of gates in channel proteins?

To open and close the pore in response to external signals (A) Signup and view all the answers

What type of transport occurs through channels?

Passive transport (A) Signup and view all the answers

What is the optimal temperature condition for enzyme catalysis?

A moderate temperature to allow the greatest number of molecular collisions (A) Signup and view all the answers

Why are enzymes sensitive to pH?

Because the catalytic groups are usually ionizable (D) Signup and view all the answers

What happens to the enzyme's active site at pH values below 7?

The active site becomes disrupted due to conformational change (C) Signup and view all the answers

What is the purpose of allosteric activators or inhibitors?

To modulate enzymatic activity (C) Signup and view all the answers

What are cofactors in enzyme catalysis?

Nonprotein helpers that are required for catalytic activity (A) Signup and view all the answers

What is the function of cofactors in enzyme catalysis?

To activate enzymatic activity (C) Signup and view all the answers