1.
Which of these is not a reason why plants need a transport system?
Correct Answer
B. Too active
Explanation
Plants need a transport system to efficiently distribute water, nutrients, and hormones throughout their cells and tissues. This is necessary for their growth, metabolism, and overall functioning. The options "They can't rely on diffusion alone," "Small surface area to volume ratio," and "multicellular" all provide valid reasons for why plants need a transport system. However, the option "too active" does not accurately explain why plants require a transport system. It is not clear what "too active" refers to in this context, and it does not directly relate to the need for a transport system in plants.
2.
Xylem tissue doesn't carry...
Correct Answer
C. Organic nutrient
Explanation
Xylem tissue is responsible for transporting water and inorganic substances in plants, but it does not carry organic nutrients. These nutrients, such as sugars and amino acids, are transported by another type of tissue called phloem. The xylem tissue consists of specialized cells called tracheids and vessel elements that form a network of tubes, allowing water and minerals to move upward from the roots to the rest of the plant. Therefore, the correct answer is organic nutrient.
3.
How does phloem transport sugars?
Correct Answer
B. Translocation
Explanation
Phloem transports sugars through a process called translocation. Translocation involves the movement of sugars, mainly in the form of sucrose, from the source to the sink tissues in a plant. The source tissues, usually the leaves, produce sugars through photosynthesis and load them into the phloem. The sugars are then transported through the phloem tubes to the sink tissues, such as roots, fruits, or growing shoots, where they are utilized for growth, storage, or energy. This process of translocation ensures the distribution of sugars throughout the plant, allowing for proper growth and metabolism.
4.
The distribution of the xylem and phloem in the stem is like:
Correct Answer
B. Seperate vascular bundles around a medula
Explanation
The correct answer is "separate vascular bundles around a medula." This means that the xylem and phloem are arranged in individual bundles that are scattered around a central region called the medulla. This arrangement allows for efficient transport of water and nutrients throughout the stem.
5.
Root hair cells absorb mineral ions using
Correct Answer
A. Active transport
Explanation
Root hair cells absorb mineral ions using active transport. Active transport is the process by which cells move substances against their concentration gradient, requiring the input of energy. In the case of root hair cells, they actively transport mineral ions from an area of low concentration in the soil to an area of higher concentration inside the cell. This allows the plant to take up essential nutrients, such as potassium and nitrate ions, which are necessary for growth and development. Diffusion and osmosis, on the other hand, are passive processes that do not require energy and are not capable of moving substances against their concentration gradient.
6.
Active transport of minerals creates a water potential gradient into the
Correct Answer
roots
Explanation
The active transport of minerals by the roots creates a water potential gradient. This means that the concentration of minerals inside the roots is higher than in the surrounding soil. As a result, water moves into the roots through osmosis, from an area of lower solute concentration (the soil) to an area of higher solute concentration (the roots). This process helps the roots absorb water and nutrients efficiently from the soil.
7.
Which is the most commonly used pathway for water
Correct Answer
B. Apoplast pathway
Explanation
The apoplast pathway is the most commonly used pathway for water. In this pathway, water moves through the cell walls and intercellular spaces, bypassing the plasma membrane. It allows for efficient movement of water through the plant tissues, as it does not require crossing any membranes. The symplast pathway, on the other hand, involves water moving through the cytoplasm of the cells via plasmodesmata, while the vacuolar pathway involves water moving through the vacuoles of the cells. However, the apoplast pathway is the preferred route for water movement in most plants.
8.
In the cell wall what enables the apoplast pathway to function
Correct Answer
B. Water filled spaces
Explanation
Water filled spaces in the cell wall enable the apoplast pathway to function. The apoplast pathway is a route for water and solutes to move through the cell walls and intercellular spaces without crossing the plasma membrane. These water-filled spaces, also known as apoplasts, provide a continuous pathway for the movement of water and solutes from the roots to the leaves of plants. The presence of water-filled spaces allows for efficient transport of water and nutrients throughout the plant, contributing to its overall growth and development.
9.
In the symplast pathway through what does the water move from cell to cell?
Correct Answer
plasmodesmata
plasmodesmada
Explanation
In the symplast pathway, water moves from cell to cell through structures called plasmodesmata. Plasmodesmata are channels that connect the cytoplasm of adjacent plant cells, allowing for the movement of water, nutrients, and other substances. They play a crucial role in facilitating communication and transport between cells in plant tissues. The term "plasmodesmada" is not a correct term and does not exist, so the correct answer is plasmodesmata.
10.
The casparian strip at the endodermis blocks which pathway?
Correct Answer
A. Apoplast
Explanation
The Casparian strip is a specialized structure found in the endodermis of plant roots. It is made up of waterproof substances that block the apoplast pathway. The apoplast pathway refers to the movement of water and solutes through the cell walls and intercellular spaces of plant tissues. By blocking this pathway, the Casparian strip forces water and solutes to pass through the symplast pathway, which involves movement through the cytoplasm of cells. This selective barrier helps regulate the entry of substances into the plant and prevents the uncontrolled movement of harmful substances.
11.
The casperian strip contains what making it waterproof?
Correct Answer
C. Suberin
Explanation
The Casperian strip contains suberin, which makes it waterproof. Suberin is a waxy substance found in the cell walls of certain plant tissues, including the Casperian strip. It acts as a barrier, preventing the movement of water and solutes between cells, thus ensuring that water is properly directed through the plant and not lost through the cell walls. This waterproofing property of suberin is crucial for the efficient uptake and transport of water and nutrients in plants.
12.
Which of these is not an adaption of parenchyma?
Correct Answer
A. Elongated cells
Explanation
Parenchyma cells are the most common type of plant cells that have various functions such as storage, photosynthesis, and secretion. They can be found in different shapes and sizes. "Elongated cells" can be considered as an adaptation of parenchyma cells because they can be elongated to provide support and flexibility to the plant. On the other hand, "isodimetric" refers to cells that have equal dimensions in all three axes, which can also be seen in parenchyma cells. However, "no chloroplast" is not an adaptation of parenchyma cells because chloroplasts are commonly found in these cells and are responsible for photosynthesis.
13.
What is the role of the fibres?
Correct Answer
A. Support vessels
Explanation
The role of the fibers is to provide support to vessels. Fibers are found in the plant's vascular system, which includes xylem and phloem vessels responsible for transporting water, nutrients, and sugars throughout the plant. The fibers provide structural strength and help support the vessels, preventing them from collapsing under pressure. Therefore, their main function is to support the vessels and ensure efficient transport of water and nutrients within the plant.
14.
Why are xylem cells dead?
Correct Answer
B. Lignin is impermeable
Explanation
Xylem cells are dead because lignin, a substance found in their cell walls, makes them impermeable. This impermeability is necessary for the xylem cells to function effectively in transporting water and minerals from the roots to the rest of the plant. The presence of a nucleus is not related to the death of xylem cells.
15.
Transpiration is:
Correct Answer
B. The loss of water vapour from areal parts of the plant due to evaporation
Explanation
Transpiration is the correct answer because it refers to the process of water loss in plants through evaporation from the aerial parts, such as leaves and stems. This loss of water vapor helps in the movement of water up the xylem, but the primary focus of transpiration is on the evaporation of water from the plant rather than the movement of water through osmosis.
16.
Which of these is not an advantage of transpiration?
Correct Answer
B. Aids translocation
Explanation
Transpiration is the process by which water is lost from the leaves of plants through small openings called stomata. It plays a crucial role in the movement of water and nutrients from the roots to the rest of the plant, known as translocation. Therefore, transpiration aids in translocation rather than being a disadvantage.
17.
Because of ________ the molecules gain more kinetic energy spreading out faster. ______ also provides latent heat of vapourisation.
Correct Answer
temperature
Explanation
The increase in temperature causes the molecules to gain more kinetic energy, leading to them spreading out faster. This increased movement of molecules results in the substance undergoing a phase change, such as vaporization, where it transitions from a liquid to a gas. Additionally, the increase in temperature also provides the latent heat of vaporization, which is the amount of heat energy required to convert a substance from a liquid to a gas at a constant temperature.