Introduction to Plant Biology

Introduction to Plant Biology and Anatomy

• Plant cells are eukaryotic, meaning they have a nucleus and other membrane-bound organelles.
• Plant cells are differentiated from other eukaryotic cells by the presence of a rigid cell wall.

Cell Wall

• Provides structural support, maintaining and defining cell shape
• Resists internal pressure, controlling the rate and direction of growth
• Provides protection from physical injury
• Functions in carbohydrate storage and cell-cell interactions
• Composed of cellulose, pectin, hemicellulose, and lignin
• Primary cell wall is flexible and thin; secondary cell wall is thick and rigid
• Middle lamella glues adjacent cells together

Nucleus

• Contains genetic material (DNA) in the form of chromatin, which coils into chromosomes during cell division
• Surrounded by a nuclear envelope with pores that allow macromolecule movement
• Contains a nucleolus, which is responsible for ribosome production

Ribosomes

• Composed of rRNA and protein
• Responsible for protein synthesis
• Can be free in the cytoplasm or bound to the ER

Endoplasmic Reticulum

• Network of interconnected membranes that form a network throughout the cell's cytoplasm
• Rough ER is studded with ribosomes and is involved in protein synthesis for secretion
• Smooth ER is involved in lipid production

Dictyosomes (Golgi Apparatus)

• Flattened sacs of membrane called cisternae, involved in modifying and packaging proteins from the endoplasmic reticulum
• May also polymerize sugars into polysaccharides

Peroxisomes

• Membrane-bound sacs that detoxify byproducts of photosynthesis and are associated with chloroplasts

Mitochondria

• Powerhouses of the cell, responsible for cellular respiration, breaking down sugars and starches and producing ATP

Plastids

• Dynamic organelles with diverse functions
• Chloroplasts are green plastids responsible for photosynthesis
• Chromoplasts are colored plastids, and leucoplasts are translucent plastids

Central Vacuole

• Large, fluid-filled sac that stores water, salts, nutrients, and waste products
• Contributes to cell growth through turgor pressure
• Can store proteins, calcium, potassium, and pigments

Test your knowledge on the fundamentals of plant biology and anatomy. This quiz covers topics such as plant cell structure, including the cell wall and nucleus, as well as ribosome function. Perfect for students studying introductory plant science.