Question 1

Which of the following would be the most effective strategy to remove toxic heavy metals from a soil?

Accepted Answer

Adding plant species that have the ability to take up and accumulate heavy metals, also known as hyperaccumulators, is a proven and effective strategy for removing toxic heavy metals from soil. The hyperaccumulators absorb the heavy metals through their roots and store them in their leaves and stems, which can then be harvested and properly disposed of. Heavy irrigation (option A) may only temporarily dilute the heavy metals in the soil and could worsen the issue by contaminating groundwater. Applying fertilizers (option B) would not compete with heavy metal uptake but could potentially add more pollutants to the soil. Inoculating soil with mycorrhizae (option D) can improve plant growth but does not necessarily prevent the uptake of heavy metals.

Question 2

The rise (upward mobility/transportation)of xylem sap by the cohesion-tension mechanism begins at the

Accepted Answer

The cohesion-tension mechanism describes how water is pulled upward through the xylem from the roots to the leaves. This process begins in the leaves, where water evaporates from the surface of the leaves, creating a negative pressure that pulls water up from the roots. Therefore, the rise of xylem sap by the cohesion-tension mechanism begins at the leaves, making choice B the correct answer.

Question 3

Ignoring all other factors,what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree?

Accepted Answer

The answer of Ignoring all other factors,what kind of day...

Question 4

Most of the water taken up by a plant is

Accepted Answer

Most of the water absorbed by plants is lost through transpiration, a process where water evaporates from the surface of leaf cells into the atmosphere. This accounts for the majority of water usage by plants, far exceeding the amounts used for processes like photosynthesis or maintaining cell turgidity.

Question 5

Rhizobia,actinomycetes,and cyanobacteria all share the common feature that they can

Accepted Answer

Rhizobia, actinomycetes (specifically those in the genus Frankia), and cyanobacteria are all capable of fixing atmospheric nitrogen, converting it into a form that plants can use.

Question 6

Some botanists argue that the entire plant should be considered as a single unit rather than a composite of many individual cells.Which of the following cellular structures best supports this view?

Accepted Answer

Plasmodesmata are tiny channels that connect adjacent plant cells and allow for communication and movement of materials between them. They play a crucial role in coordinating the functions of individual cells within a plant and linking them together into a cohesive whole. Thus, the presence of plasmodesmata supports the idea that the plant should be considered as a single unit rather than a collection of separate cells.

Question 7

Pine seedlings grown in sterile potting soil grow much slower than seedlings grown in soil from the area where the seeds were collected.This is most likely because

Accepted Answer

Sterilization process kills not just harmful organisms but also the beneficial ones such as mycorrhizae which are known to improve nutrient and water uptake by the plant roots. Hence, the absence of mycorrhizae in sterile soil results in slower growth of seedlings.

Question 8

What is the main force by which most of the water within xylem vessels moves toward the top of a tree?

Accepted Answer

The main force by which most of the water within xylem vessels moves toward the top of a tree is the evaporation of water through stoma. This process is called transpiration and creates a negative pressure gradient that pulls water up from the roots through the xylem. Atmospheric pressure on roots and root pressure are minor forces compared to transpiration. Active transport of ions into the stele is involved in mineral uptake by roots but not in water movement within the xylem.

Question 9

What are epiphytes?

Accepted Answer

Epiphytes are plants that live on other plants, but do not obtain nutrients from their hosts. Instead, they derive their nutrients from the air and rain. They are commonly found in tropical regions and can include ferns, bromeliads, and orchids.

Question 10

The water and minerals in the xylem vessels transported by

Accepted Answer

The transportation of water and minerals in the xylem vessels is done through bulk flow or mass flow, which is a type of transport mechanism that involves the movement of substances in response to pressure differences or gradients. This process requires energy and is, therefore, an active transport mechanism. Diffusion and passive transport, on the other hand, involve the movement of substances from high to low concentration gradients without the need for energy. Therefore, the best choice is C, bulk flow.

Question 11

Nitrogen fixation is a process that

Accepted Answer

Nitrogen fixation is the process of converting atmospheric nitrogen gas into a usable form, such as ammonia. This is typically done by certain bacteria, which can then be used by other organisms in the ecosystem. Choice A is describing the process of nitrogen cycling, where nitrogen is transferred between living and non-living components of the ecosystem. Choice B refers to a specific conversion of ammonia to ammonium, but not the overall process of nitrogen fixation. Choice C describes the release of nitrate from rock, but not the process of nitrogen fixation.

Question 12

A plant developed a mineral deficiency after being treated with a fungicide.What is the most probable cause of the deficiency?

Accepted Answer

Mycorrhizal fungi form symbiotic relationships with plants, aiding in the absorption of minerals from the soil. The application of fungicide likely killed these beneficial fungi, leading to a mineral deficiency in the plant.

Question 13

Carnivorous plants have evolved mechanisms that trap and digest small animals.The products of this digestion are used to supplement the plant's supply of

Accepted Answer

Carnivorous plants obtain their nutrients, especially minerals like nitrogen and phosphorus, from the digestion of small animals. While they do derive some energy from the digestion process, they primarily rely on photosynthesis for energy production. Carbohydrates and water are also obtained through photosynthesis.

Question 14

What drives the flow of water through the xylem?

Accepted Answer

The flow of water through the xylem is driven by transpiration, which is the evaporation of water from the leaves. As water evaporates from the leaves, it creates a negative pressure or tension in the xylem, causing water to move up from the roots to replace the lost water. This process is known as transpiration pull and is responsible for the movement of water and minerals through the xylem. Passive transport by the endodermis, the number of companion cells in the phloem, and active transport by tracheid and vessel elements do not drive the flow of water through the xylem.

Question 15

The Casparian strip in plant roots is correctly described by which of the following?

Accepted Answer

The Casparian strip is a specialized cell wall found in the endodermis of plant roots that prevents water and dissolved substances from moving between adjacent cells. As a result, all water and dissolved substances must pass through a cell membrane before entering the stele, which enables the plant to regulate and control the composition of the xylem sap. This mechanism ensures that only selected minerals and nutrients are taken up by the plant, and that they are absorbed in the correct proportions.

Question 16

A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once.This living cell would be a part of which structure?

Accepted Answer

The endodermis is a specialized layer of cells located in the root that regulates the movement of water and minerals into the vascular tissue of the plant. The Casparian strip and the root epidermis are also involved in this process, but they do not have the same specialization as the endodermis. The guard cell is not involved in the movement of water through the plant, but instead regulates gas exchange in the leaf. Therefore, the correct answer is D) the endodermis.

Question 17

The water lost during transpiration is a side effect of the plant's exchange of gases.However,the plant derives some benefit from this water loss in the form of

Accepted Answer

Transpiration helps in evaporative cooling of the plant, which is essential for preventing overheating and maintaining optimal temperature. Additionally, as water evaporates from the leaves, it creates a negative pressure that helps in the transport of minerals and nutrients from the roots to other parts of the plant. Hence, the best choice would be D, which combines both benefits of evaporative cooling and mineral transport.

Question 18

The transpiration pull is due to the ________ that causes water to move up through the xylem that begins at the surface of mesophyll cells.

Accepted Answer

The negative pressure potential created by transpiration from the leaves is what causes water to move up through the xylem. This pull is what allows water to move against gravity and distribute throughout the plant. Positive pressure potential would push water out of the xylem, and solute and solvent potential are factors that contribute to overall water potential but are not specifically associated with the transpiration pull.

Question 19

The earliest vascular plants on land had underground stems (rhizomes)but no roots.Water and mineral nutrients were most likely obtained by

Accepted Answer

The earliest vascular plants on land formed mutualistic relationships with fungi, which developed into mycorrhizae. These mycorrhizae helped the plants absorb water and mineral nutrients from the soil, as the plants lacked true roots.

Question 20

Which of the following plant structures shares the most common features and functions with a fungal hyphae?

Accepted Answer

Root hairs are thin, elongated structures that resemble fungal hyphae in their morphology and function. They both facilitate the absorption of nutrients from the surrounding environment.

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