Cell Cycle, Fungi, and Plant Diversity: Study Guide

Cell Cycle

Overview of the Cell Cycle

The cell cycle is a series of events that cells undergo to grow and divide. It is fundamental to all living organisms and ensures genetic continuity.

• Phases: The cell cycle consists of interphase (G1, S, G2) and the mitotic phase (mitosis and cytokinesis).

• Interphase: Cells grow (G1), replicate DNA (S), and prepare for division (G2).

• Mitosis: Division of the nucleus into two genetically identical daughter cells.

• Cytokinesis: Division of the cytoplasm, resulting in two separate cells.

Example: Skin cells undergo the cell cycle to replace damaged tissue.

Key Terms

• Checkpoint: Regulatory points that ensure proper cell cycle progression.

• Apoptosis: Programmed cell death, important for development and homeostasis.

Kingdom Fungi

Characteristics of Fungi

Fungi are a diverse group of eukaryotic organisms that play essential roles in ecosystems as decomposers, symbionts, and pathogens.

• Cell Structure: Fungi have cell walls made of chitin.

• Nutrition: Heterotrophic, absorbing nutrients from their environment.

• Reproduction: Both sexual and asexual reproduction, often via spores.

Example: Penicillium produces the antibiotic penicillin.

Classification of Fungi

• Major Groups: Includes Ascomycota, Basidiomycota, Zygomycota, and Chytridiomycota.

• Ecological Roles: Decomposers, mutualists (e.g., mycorrhizae), and pathogens.

Plantae I: Non-Vascular Plants

Characteristics of Non-Vascular Plants

Non-vascular plants, also known as bryophytes, lack specialized vascular tissues for water and nutrient transport.

• Groups: Mosses, liverworts, and hornworts.

• Habitat: Typically found in moist environments.

• Life Cycle: Dominant gametophyte stage; sporophyte is dependent on gametophyte.

Example: Marchantia is a common liverwort.

Adaptations

• Water Retention: Lack of cuticle and roots limits water retention.

• Reproduction: Requires water for sperm motility.

Plantae II: Seedless Vascular Plants

Characteristics of Seedless Vascular Plants

Seedless vascular plants possess vascular tissues (xylem and phloem) but reproduce via spores rather than seeds.

• Groups: Ferns, horsetails, and club mosses.

• Life Cycle: Dominant sporophyte stage; gametophyte is independent but short-lived.

• Vascular Tissues: Allow for greater size and complexity compared to non-vascular plants.

Example: Pteridium (bracken fern) is a widespread seedless vascular plant.

Adaptations

• Vascular System: Efficient transport of water and nutrients.

• Reproduction: Spores dispersed by wind; still require water for fertilization.

Lab Materials

Fungi Lab

• Objective: Observe fungal structures and understand their ecological roles.

• Key Activities: Identification of fungal groups, examination of spores, and study of symbiotic relationships.

Plants Lab

• Objective: Explore plant diversity, focusing on non-vascular and seedless vascular plants.

• Key Activities: Identification of plant groups, observation of life cycles, and comparison of adaptations.