Question

A vascular bundle in a leaf is called a. xylem b. mesophyll c. a vein

Short answer

The correct answer is c. a vein.

Step-by-step solution

Understand the Question

The question is asking for the term used to describe a vascular bundle within a leaf. It's a multiple-choice question where you are required to select the correct term from the options provided.

Identify the Function of Each Term

Review the definitions and functions of the given options: - **Xylem**: Part of the vascular system of plants that transports water and dissolved minerals from the roots to the rest of the plant. - **Mesophyll**: Tissue in the leaf where photosynthesis occurs, typically between the upper and lower epidermis. - **Vein**: A part of the vascular system in plants, primarily responsible for the transport of nutrients, water, and carbohydrates in the leaf.

Determine the Correct Answer

A vascular bundle includes both xylem and phloem, and is generally found in the structure called a vein within the leaf. Thus, the correct answer should reflect the term that encompasses the presence of vascular tissue within the leaf.

Key concepts

Xylem

The xylem is a critical component of a plant's vascular system, responsible for the transportation of water and minerals. This process begins at the roots, where water is absorbed from the soil. From there, the xylem tissues, composed mainly of tracheids and vessel elements, aid in moving this water upward through the plant. The movement relies on capillary action and the transpirational pull created by water evaporation from the leaves.

Here's how the xylem functions:

• Transports water and soluble mineral nutrients from the roots to various parts of the plant.
• Provides structural support due to the lignin strengthening the walls of the xylem cells.
• Plays a role in water storage during times of excess supply.

A healthy xylem system ensures that every part of the plant receives the water and nutrients it needs to thrive.

Mesophyll

The mesophyll layer in a leaf is where the magic of photosynthesis happens. Situated between the upper and lower epidermis, mesophyll is composed of two distinct layers: palisade mesophyll and spongy mesophyll. Both are crucial for the leaf’s role in capturing sunlight and converting it into chemical energy.

Let's take a closer look:

• **Palisade Mesophyll:** Tightly packed cylindrical cells that are rich in chloroplasts. This layer is responsible for capturing the bulk of the light energy required for photosynthesis.
• **Spongy Mesophyll:** Consists of loosely arranged cells with air spaces in between to facilitate gas exchange. This structure enables effective movement of carbon dioxide and oxygen.

Photosynthesis in the mesophyll involves capturing light energy to convert carbon dioxide and water into glucose and oxygen. This process is vital for plant growth and oxygen production in the environment.

Leaf Vein

Within a leaf, the veins are the visible structures that contain the vascular bundles, which include both xylem and phloem tissues. These veins are essential for transporting nutrients, water, and carbohydrates throughout the leaf and back into the rest of the plant.

Here's what you need to know about leaf veins:

• They support the structural framework of the leaf, preventing it from wilting and bending under its own weight.
• Veins distribute water from the xylem and transport carbohydrates produced by photosynthesis via the phloem to other parts of the plant.
• The pattern of veins, known as venation, can vary greatly among plant species, influencing the efficiency of nutrient transport and water distribution.

A well-functioning vein system is fundamental to the health and efficiency of a plant, ensuring that every part of the leaf is fed and hydrated.