Plant Biology: Palisade Mesophyll Cells

Questions and Answers

Which of the following are components of a palisade mesophyll cell in a leaf? (Select all that apply)

Spongy mesophyll (correct)

Waxy cuticle (correct)

Cuticle layer

Vascular bundle (correct)

Palisade mesophyll cells (correct)

Upper epidermis (correct)

What is the structure of the waxy cuticle?

A waxy layer positioned above the upper epidermis, composed of cutin, polysaccharides, and waxes.

What is the function of the waxy cuticle?

Acts as a waterproof layer for the cell and helps reduce water loss by evaporation.

Describe the structure of the upper epidermis.

A skin layer that contains lots of tightly packed, transparent cells allowing light to pass through to the palisade layer. Signup and view all the answers

What is the function of the upper epidermis?

Protects the leaf and aids in reducing water loss through evaporation. Signup and view all the answers

What is the structure of the palisade mesophyll cell?

Vertically elongated, cylindrical, containing numerous chloroplasts and thin gaps for air circulation. Signup and view all the answers

What is the primary function of the palisade mesophyll cell?

Major site of photosynthesis and conducts gas exchange by diffusion. Signup and view all the answers

What is photosynthesis? State its equation.

The process by which green plants synthesize nutrients from carbon dioxide and water using sunlight. The equation is 6CO2 + 6H2O → C6H12O6 + 6O2. Signup and view all the answers

Describe the structure of the spongy mesophyll.

Contains loosely packed cells with air gaps for efficient gas exchange, forms a layer beneath the palisade mesophyll cells. Signup and view all the answers

What is the function of the spongy mesophyll?

Allows increased rate of diffusion and gas interchange required for photosynthesis. Signup and view all the answers

What is the structure of the vascular bundle?

Consists of phloem and xylem, which are primary tissue strands found in the leaf stem. Signup and view all the answers

What is the function of the vascular bundle?

Xylem transports water and nutrients up the leaf, while phloem transports organic molecules. Signup and view all the answers

Describe the structure and function of the stomata.

Minute pores surrounded by guard cells that open and close to regulate water loss and allow gas exchange. Signup and view all the answers

Study Notes

Components of a Palisade Mesophyll Cell

Waxy cuticle, upper epidermis, palisade mesophyll cells, spongy mesophyll, vascular bundle, and stomata are key components of a leaf structure.

Waxy Cuticle

A protective waxy layer above the upper epidermis made of cutin, polysaccharides, and waxes.
Functions as a waterproof barrier, minimizing water loss through evaporation.

Upper Epidermis

Composed of tightly packed, transparent cells that allow light penetration to the palisade layer.
Protects the leaf and reduces water loss, serving as an external barrier.

Palisade Mesophyll Cells

Located beneath the waxy cuticle and upper epidermis; characterized by vertical, cylindrical shapes.
Rich in chloroplasts oriented at right angles to the upper epidermis for optimal light absorption.
Features long gaps for air circulation, a large central vacuole, and a responsive cytoskeleton that adjusts chloroplast position based on light intensity.

Function of Palisade Mesophyll Cells

Primary site for photosynthesis, facilitating gas exchange via diffusion.
Adapted for efficient light absorption due to chloroplast arrangement and cell structure.

Photosynthesis

Biological process where plants convert sunlight into chemical energy, utilizing carbon dioxide and water.
General equation: 6CO2 + 6H2O → C6H12O6 + 6O2, yielding glucose and oxygen.

Spongy Mesophyll

Layer beneath the palisade mesophyll, composed of loosely packed cells with air gaps.
Structure promotes efficient gas exchange necessary for photosynthesis.

Function of Spongy Mesophyll

Air gaps enhance gas diffusion rates, facilitating the exchange of gases crucial for photosynthesis.

Vascular Bundle

Includes two main components: phloem and xylem, forming major transport structures within the leaf.
Xylem carries water and nutrients upwards, while phloem distributes organic molecules throughout the plant.

Stomata

Comprised of small pores (stoma) controlled by guard cells that regulate their opening and closing based on water availability.
Facilitate gas exchange between the leaf's internal and external environment through diffusion.

Description

Explore the essential components and functions of palisade mesophyll cells in leaves. This quiz covers the structure, significance, and roles of the waxy cuticle, upper epidermis, and chloroplasts. Test your knowledge on plant anatomy and photosynthesis efficiency.