Question 1

If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa,which of the following would be the most likely outcome?

Accepted Answer

The pressure potential of the cells would increase because water moves from areas of higher water potential to areas of lower water potential. Since the solution's water potential (-0.3 MPa) is higher than that of the cells (-0.5 MPa), water would move into the cells, increasing their pressure potential.

Question 2

Arrange the following five events in an order that explains the mass flow of materials in the phloem.
1)Water diffuses into the sieve tubes.
2)Leaf cells produce sugar by photosynthesis.
3)Solutes are actively transported into sieve tubes.
4)Sugar is transported from cell to cell in the leaf.
5)Sugar moves down the stem.

Accepted Answer

The correct sequence starts with leaf cells producing sugar by photosynthesis (2), then sugar is transported from cell to cell within the leaf (4). Next, solutes (including the produced sugars) are actively transported into sieve tubes (3), causing water to diffuse into the sieve tubes due to osmotic pressure (1), and finally, sugar (along with other solutes) moves down the stem (5).

Question 3

Which of the following essential nutrients plays an essential role in the opening and closing of the stomatal aperture?

Accepted Answer

Potassium (K) plays an essential role in the opening and closing of the stomatal aperture. When a plant loses water, cells in the guard cells of the stomata release K+ ions, causing water to leave the cells, and the stomata close. When there is enough water, K+ ions enter the cells, water follows, and the stomata open. Therefore, K is an essential nutrient for regulating gas exchange and water balance in plants.

Question 4

Active transport would be least important in the normal functioning of which of the following plant tissue types?

Accepted Answer

Stem tracheid elements are part of the xylem, which primarily functions in the passive transport of water and minerals from roots to leaves. Active transport is less crucial in these cells compared to others listed, which are more directly involved in nutrient and ion exchange requiring energy.

Question 5

Which of the following macronutrients plays a critical role on plant growth and crop yields?

Accepted Answer

The answer of Which of the following macronutrients plays a...

Question 6

Atmospheric nitrogen can be fixed by nitrogen-fixing bacteria.Arrange the following forms of nitrogen from the atmospheric N stage to the final form that enters the roots.
1)Ammonia
2)Nitrogen gas
3)Ammonium ion
4)Nitrite
5)Nitrate

Accepted Answer

The correct sequence starts with nitrogen gas (N2) being fixed into ammonia (NH3) by nitrogen-fixing bacteria. Ammonia can then be converted into the ammonium ion (NH4+), which is further processed into nitrite (NO2-) and finally into nitrate (NO3-), the form most readily absorbed by plant roots.

Question 7

Phloem transport is described as being from source to sink.Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring?
Phloem transports ________ from the ________ source to the ________ sink.

Accepted Answer

In late spring, most plants have active leaves that are photosynthesizing and producing sugars, which are the main nutrients transported through the phloem. The leaves are the source of these sugars, and the sink is often the growing apical meristem or developing fruits. Therefore, phloem transports sugars from the leaf source to the apical meristem or fruit sink. None of the other options are consistent with typical phloem transport in plants.

Question 8

Which of the following is a correct statement about sugar movement in phloem?

Accepted Answer

Sugar movement in phloem can occur in both upward and downward directions in the plant. This is because the phloem transport system is bidirectional, meaning that sugar can be transported both towards the leaves and towards the roots. The movement of sugar in phloem is an active process that requires energy and relies on specialized cells known as sieve elements. The movement of sugar is not fully explained by diffusion alone, as the observed rates of transport are much faster than can be accounted for by simple diffusion. Sugar is typically translocated from sources, where it is produced through photosynthesis or is stored in organs such as roots and stems, to sinks, where it is used for energy or storage. Phloem cells do not require nuclei to perform sugar movement.

Question 9

Why does overwatering a plant kill it?

Accepted Answer

Overwatering can lead to waterlogged soil, which deprives the roots of oxygen. Without oxygen, the roots cannot carry out important functions such as absorbing nutrients and anchoring the plant, eventually resulting in root rot and potentially killing the plant.

Question 10

What is the role of proton pumps in root hair cells?

Accepted Answer

Proton pumps in root hair cells are primarily involved in maintaining the H+ (proton) gradient across the cell membrane. This gradient is crucial for various cellular processes, including nutrient uptake through co-transport mechanisms.

Question 11

The opening of stomata is thought to involve

Accepted Answer

The opening of stomata is thought to involve an increase in the solute concentration of the guard cells, which causes water to move into them, increasing their turgor pressure and causing them to swell and separate, opening the stomatal pore.

Question 12

In which plant cell or tissue would the pressure component of water potential most often be negative?

Accepted Answer

The pressure component of water potential is the pressure exerted by the cell wall on the protoplast. In stem xylem, the water is under tension, which creates a negative pressure, also known as negative pressure potential. This allows the water to be pulled up from the roots to the leaves via transpiration. In the other choices, the pressure potential is either zero or positive.

Question 13

For this pair of items,choose the option that best describes their relationship.
(a)The average size of particles that constitute silt
(b)The average size of particles that constitute clay

Accepted Answer

The average size of particles that make up silt is larger than those that make up clay. Silt particles are finer than sand but coarser than clay particles.

Question 14

Which of the following is considered an organic fertilizer?

Accepted Answer

Manure is considered an organic fertilizer because it is derived from natural sources such as animal waste and plant material. The other options listed are either synthetic fertilizers or a specific brand of fertilizer.

Question 15

A fertilizer marked "20-10-5" is

Accepted Answer

The three numbers in the fertilizer mark represent the percentage by weight of nitrogen (N), phosphorus (P), and potassium (K) contained in the fertilizer. Therefore, a fertilizer marked "20-10-5" contains 20% nitrogen (as ammonium nitrate), 10% phosphorus (as phosphate), and 5% potassium (as the mineral potash). Choice A matches this description.

Question 16

If you wanted to increase the cation exchange and water retention capacity of loamy soil,what should you do?

Accepted Answer

Adding clay to loamy soil will increase the cation exchange capacity and water retention capacity. Loamy soil already has a balanced amount of sand, silt, and clay, so adjusting the pH would not be necessary. No-till agriculture can help improve soil structure and organic matter content, but it would not specifically increase cation exchange or water retention. Fertilizer containing potassium, calcium, and magnesium would improve plant growth, but it would not necessarily increase cation exchange or water retention capacity.

Question 17

Photosynthesis begins to decline when leaves wilt because

Accepted Answer

When leaves wilt, stomata close to conserve water, which restricts the entry of carbon dioxide needed for photosynthesis. Without sufficient carbon dioxide, the rate of photosynthesis declines. Additionally, closed stomata also limit the availability of water for photolysis during the light reactions.

Question 18

Guard cells do which of the following?

Accepted Answer

Guard cells play a crucial role in regulating the opening and closing of stomata, which in turn helps balance the photosynthesis-transpiration compromise. By opening the stomata, they allow for gas exchange necessary for photosynthesis, but also allow for water vapor to escape through transpiration. By closing the stomata, they reduce water loss but also limit the intake of CO2 required for photosynthesis. Therefore, guard cells help balance the trade-off between water loss and CO2 uptake, which is essential for plant survival. The other options listed are incorrect.

Question 19

Which of the following has the lowest (most negative)water potential?

Accepted Answer

Leaf air spaces have the lowest (most negative) water potential because water potential decreases as water moves from the soil into the roots, up through the plant, and eventually evaporates into the air spaces of leaves, a process driven by transpiration.

Question 20

The size of clay particles ranges from ________ in diameter.

Accepted Answer

Clay particles are the smallest among the three main soil particle types (sand, silt, and clay), with a diameter smaller than 0.002 mm.

Quiz 29: Resource Acquisition,nutrition,and Transport in Vascular Plants

If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa,which of the following would be the most likely outcome?

Which of the following essential nutrients plays an essential role in the opening and closing of the stomatal aperture?

Active transport would be least important in the normal functioning of which of the following plant tissue types?

Which of the following macronutrients plays a critical role on plant growth and crop yields?

Atmospheric nitrogen can be fixed by nitrogen-fixing bacteria.Arrange the following forms of nitrogen from the atmospheric N stage to the final form that enters the roots. 1) Ammonia 2) Nitrogen gas 3) Ammonium ion 4) Nitrite 5) Nitrate

Phloem transport is described as being from source to sink.Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring? Phloem transports from the source to the sink.

Which of the following is a correct statement about sugar movement in phloem?

Why does overwatering a plant kill it?

What is the role of proton pumps in root hair cells?

The opening of stomata is thought to involve

In which plant cell or tissue would the pressure component of water potential most often be negative?

For this pair of items,choose the option that best describes their relationship. (a) The average size of particles that constitute silt (b) The average size of particles that constitute clay

Which of the following is considered an organic fertilizer?

A fertilizer marked "20-10-5" is

If you wanted to increase the cation exchange and water retention capacity of loamy soil,what should you do?

Photosynthesis begins to decline when leaves wilt because

Guard cells do which of the following?

Which of the following has the lowest (most negative) water potential?

The size of clay particles ranges from ________ in diameter.

Quiz 29: Resource Acquisition,nutrition,and Transport in Vascular Plants

If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa,which of the following would be the most likely outcome?

Which of the following essential nutrients plays an essential role in the opening and closing of the stomatal aperture?

Active transport would be least important in the normal functioning of which of the following plant tissue types?

Which of the following macronutrients plays a critical role on plant growth and crop yields?

Atmospheric nitrogen can be fixed by nitrogen-fixing bacteria.Arrange the following forms of nitrogen from the atmospheric N stage to the final form that enters the roots. 1) Ammonia 2) Nitrogen gas 3) Ammonium ion 4) Nitrite 5) Nitrate

Phloem transport is described as being from source to sink.Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring? Phloem transports ________ from the ________ source to the ________ sink.

Which of the following is a correct statement about sugar movement in phloem?

Why does overwatering a plant kill it?

What is the role of proton pumps in root hair cells?

The opening of stomata is thought to involve

In which plant cell or tissue would the pressure component of water potential most often be negative?

For this pair of items,choose the option that best describes their relationship. (a) The average size of particles that constitute silt (b) The average size of particles that constitute clay

Which of the following is considered an organic fertilizer?

A fertilizer marked "20-10-5" is

If you wanted to increase the cation exchange and water retention capacity of loamy soil,what should you do?

Photosynthesis begins to decline when leaves wilt because

Guard cells do which of the following?

Which of the following has the lowest (most negative) water potential?

The size of clay particles ranges from ________ in diameter.

Phloem transport is described as being from source to sink.Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring? Phloem transports from the source to the sink.