plant cell Flashcards
What are the unique features of plant cells compared to animal cells?
Plant cells have unique structures, including:
The cell wall
Plastids (e.g., chloroplasts)
The vacuole
What are the functions of the plant cell wall?
Maintains and determines cell shape
Supports the development of specialized cells
Controls growth rate and direction
Protects against pathogens and environmental stress
Maintains turgor pressure
Facilitates cell-to-cell interactions
What are the three layers of the plant cell wall?
The cell wall is composed of:
Hemicellulose
Cellulose
Pectin
How does fruit ripening relate to cell walls?
Ripening involves changes in cell wall structure and composition, such as the reduction of pectin.
What is the secondary cell wall, and what is its purpose?
The secondary cell wall forms after the primary wall stops expanding. It provides support, strength, and protection, often containing materials like lignin and cellulose.
What is abscission in plants?
Abscission is the process by which plants remove organs (e.g., leaves, petals, fruit). A protective layer forms around the abscission zone, and the middle lamella is digested to release the organ.
What is the function of root hairs?
Root hairs are single cells originating from the epidermis. They increase the surface area for water and nutrient uptake and have thin cell walls for efficient absorption.
What are xylem cells, and what is their role?
Xylem cells are elongated, have secondary cell walls, and die at maturity. They passively conduct water through the plant.
How do phloem cells differ from xylem cells?
Phloem cells actively transport sugars and amino acids in both directions. They have perforated sieve plates and are supported by companion cells.
What are stomata, and what is their function?
Stomata are specialized structures in the epidermis that facilitate gas exchange. Their opening and closing regulate water loss and photosynthesis.
What are plastids, and what types are found in plant cells?
lastids are organelles involved in storage and synthesis. Types include:
Chloroplasts (photosynthesis)
Chromoplasts (pigment storage)
Amyloplasts (starch storage)
Elaioplasts (lipid storage)
Describe the structure and function of chloroplasts.
Chloroplasts contain genetic material and are surrounded by inner and outer membranes. They have:
Grana: Stacked thylakoids where light reactions occur
Stroma: Fluid matrix where CO2 fixation takes place
What are the roles of the vacuole in plant cells?
The vacuole maintains cell homeostasis, turgor pressure, detoxification, and storage. It often contains acidic fluid and pigments.
What are trichomes, and what is their function?
Trichomes are small hairs on the epidermis. They can be unicellular or multicellular and branched or unbranched, providing protection and reducing water loss.
What is the function of the Casparian strip in roots?
The Casparian strip is a specialized structure in root cells that controls water and nutrient flow into the vascular system by acting as a barrier.
