Plant Biology: Tissues and Photosynthesis

• Plants are eukaryotic organisms containing chlorophyll
• Plant cell walls are made of cellulose
• Plants get energy through photosynthesis, making them autotrophic

Photosynthesis Equation

• 6CO2 + 6H2O → C6H12O6 + 6O2

• Carbon dioxide + water becomes glucose and oxygen

• Plants provide food and oxygen for other living organisms

• Levels of cell organization in plants: cells → tissues → organ → organ system → organism

• Plant histology studies plant tissues

• A tissue is a group of similar cells with the same structure and function

• There are four basic tissue types: meristematic, dermal, vascular, and ground

Meristematic Tissue

• Meristematic tissue consists of meristematic cells
• Meristematic cells are capable of cell division
• Meristematic tissue gives rise to other tissues/organs in a plant responsible for growth
• Meristems create indeterminate growth
• Meristematic tissue is located in specific growth zones

Types of Meristems

• Apical meristems: located at the tips of shoots (in buds) and roots
• Shoots are the above-ground parts of the plant
• Lateral meristems: located along the sides of a plant

Dermal Tissue

• Dermal tissue is the thin, outer cell layer covering plant parts
• Dermal cells are flattened, close together, and have no intercellular spaces
• Epidermis: dermal tissue found on stems, leaves, flowers, and fruits
• Rhizodermis: dermal tissue found on roots

Cuticle

• The cuticle is a waxy layer made of cutin on the surface of the epidermis
• The cuticle helps prevent water evaporation, repels water, and waterproofs the plant

Dermal Tissue Functions

• Dermal tissue protects from the environment and mechanical injury
• It ensures protection from water loss
• It allows communication with the environment