8.1

Xylem and phloem

10 flashcards to master Xylem and phloem

Smart Spaced Repetition

Rate each card Hard, Okay, or Easy after flipping. Your progress is saved and cards are scheduled for optimal review intervals.

Definition Flip

What are the two primary functions of xylem?

Answer Flip

Xylem's main functions are to transport water and dissolved mineral ions from the roots to the leaves and other parts of the plant. Additionally, xylem provides structural support to the plant due to its rigid cell walls containing lignin.

Example: Water is transported upwards to supply the leaves of a tall oak tree.
Definition Flip

What is the main function of phloem?

Answer Flip

Phloem transports sucrose (sugars) and amino acids, the products of photosynthesis, from source (e.g., leaves) to sink (e.g., roots, developing fruits) where they are used for growth or storage. This process is called translocation.

Example: Phloem transports sucrose from the leaves of a tomato plant to its developing fruit.
Key Concept Flip

In a non-woody dicotyledonous stem, where are xylem and phloem located relative to each other?

Answer Flip

In a non-woody dicotyledonous stem, xylem is located towards the center of the stem, while phloem is located towards the outside, closer to the epidermis. They are arranged in vascular bundles.

Example: In a cross-section of a sunflower stem, xylem occupies the inner portion of the vascular bundles, while phloem is on the outer side.
Key Concept Flip

In a non-woody dicotyledonous root, how are xylem and phloem arranged?

Answer Flip

In a non-woody dicotyledonous root, xylem forms a central core, often star-shaped. Phloem is located in patches between the arms of the xylem star.

Example: In a buttercup root, the xylem forms a central star-shaped structure, with phloem found in the spaces between the points of the star.
Key Concept Flip

In a non-woody dicotyledonous leaf, where are xylem and phloem found?

Answer Flip

In a non-woody dicotyledonous leaf, xylem and phloem are located within the vascular bundles of the leaf veins. Xylem is typically found on the upper side of the vein, while phloem is on the lower side.

Example: In a maple leaf, the veins contain xylem on the upper side and phloem on the lower side of the vein.
Key Concept Flip

How does the presence of lignin in xylem vessel walls relate to their function?

Answer Flip

The lignin in xylem vessel walls provides strength and rigidity, preventing the vessels from collapsing under the tension created by the transpiration stream. This allows efficient water transport and provides support to the plant.

Example: The lignified xylem walls enable tall trees, like redwoods, to maintain water transport up to great heights.
Key Concept Flip

How does the absence of cell contents in mature xylem vessels relate to their function?

Answer Flip

The absence of cell contents in mature xylem vessels reduces resistance to water flow, allowing for efficient and uninterrupted transport of water and mineral ions. This creates a clear, unobstructed pathway.

Example: Water can move freely through the hollow xylem vessels in celery stalks.
Key Concept Flip

How does the arrangement of xylem cells (end to end with no cross walls) benefit water transport?

Answer Flip

The arrangement of xylem cells joined end to end, without cross walls, forms long, continuous tubes. This allows for uninterrupted water flow from the roots to the leaves, facilitating the transpiration stream.

Example: The continuous xylem vessels in a rose stem enable efficient delivery of water to the petals.
Key Concept Flip

What property of xylem allows plants to grow tall?

Answer Flip

The lignin in the walls of xylem vessels provides structural support. This structural support enables plants, such as giant sequoia trees, to grow to great heights without collapsing.

Definition Flip

What is translocation?

Answer Flip

Translocation is the process by which phloem transports sucrose and amino acids from source (e.g., leaves) to sink (e.g., roots, developing fruits) throughout the plant.

Example: Translocation moves sucrose from the leaves of an apple tree to the developing apples.

Review the material

Read revision notes with definitions, equations, and exam tips.

Read Notes

Test yourself

Practice with MCQ questions to check your understanding.

Take Quiz
7.5 Absorption 8.2 Water uptake

Key Questions: Xylem and phloem

What are the two primary functions of xylem?

Xylem's main functions are to transport water and dissolved mineral ions from the roots to the leaves and other parts of the plant. Additionally, xylem provides structural support to the plant due to its rigid cell walls containing lignin.

Example: Water is transported upwards to supply the leaves of a tall oak tree.
What is the main function of phloem?

Phloem transports sucrose (sugars) and amino acids, the products of photosynthesis, from source (e.g., leaves) to sink (e.g., roots, developing fruits) where they are used for growth or storage. This process is called translocation.

Example: Phloem transports sucrose from the leaves of a tomato plant to its developing fruit.
What is translocation?

Translocation is the process by which phloem transports sucrose and amino acids from source (e.g., leaves) to sink (e.g., roots, developing fruits) throughout the plant.

Example: Translocation moves sucrose from the leaves of an apple tree to the developing apples.

About Xylem and phloem (8.1)

These 10 flashcards cover everything you need to know about Xylem and phloem for your Cambridge IGCSE Biology (0610) exam. Each card is designed based on the official syllabus requirements.

What You'll Learn

How to Study Effectively

Use the Study Mode button above to test yourself one card at a time. Try to answer each question before flipping the card. Review cards you find difficult more frequently.

Continue Learning

After mastering Xylem and phloem, explore these related topics: