BIO 1272 Lab Exam 2: Study Notes on Protists, Plants, and Fungi

Algae & Protozoa (Protists)

Overview of Protists

Protists are a diverse group of mostly unicellular eukaryotic organisms, including both algae (photosynthetic) and protozoa (heterotrophic). They are commonly found in aquatic environments and are studied for their structural diversity and ecological roles.

• Algae: Photosynthetic protists, such as Chlamydomonas, Spirogyra, and Volvox.

• Protozoa: Heterotrophic protists, including Amoeba, Paramecium, and Euglena (which is mixotrophic).

• Key Structures: Cell wall (in algae), chloroplasts, flagella, cilia, pseudopodia, contractile vacuole, nucleus.

Example: Paramecium uses cilia for movement and feeding, while Volvox forms colonies of cells with coordinated movement.

Mosses

Characteristics and Identification

Mosses are non-vascular plants belonging to the phylum Bryophyta. They are small, green, and typically found in moist environments. Mosses lack true roots, stems, and leaves but have analogous structures.

• Special Moss: Sphagnum (peat moss), known for its water-absorbing capacity.

• Key Structures: Capsule (sporangium), seta (stalk), protonema, rhizoids.

Example: Sphagnum is used in horticulture for its ability to retain water.

Ferns

Characteristics and Identification

Ferns are seedless vascular plants in the phylum Pteridophyta. They reproduce via spores and have true roots, stems, and leaves (fronds).

• Major Plant Groups: Ferns are part of the seedless vascular plants, distinct from bryophytes (mosses) and seed plants (gymnosperms and angiosperms).

• Key Structures: Frond, sori (clusters of sporangia), fiddlehead (young frond), rhizome.

Example: Sori are visible as small dots on the underside of fern fronds.

Gymnosperms

Characteristics and Identification

Gymnosperms are seed plants that produce seeds not enclosed in fruits. They include conifers, cycads, ginkgo, and gnetophytes.

• Key Structures: Needle-like leaves, cones (strobili), vascular tissue.

• Male vs Female Cones: Male cones produce pollen; female cones contain ovules and develop seeds.

Example: Pine trees (Pinus) have both small, soft male cones and larger, woody female cones.

Angiosperms

Characteristics and Identification

Angiosperms are flowering plants that produce seeds enclosed within fruits. They are the most diverse group of land plants.

• Key Structures: Flowers (with sepals, petals, stamens, carpels), fruits, vascular tissue.

• Floral Organs:

  • Sepals: Protect the flower bud.

  • Petals: Attract pollinators.

  • Stamens: Male organs (anther and filament).

  • Carpels (Pistil): Female organs (stigma, style, ovary).

• Fruits: Develop from the ovary after fertilization; aid in seed dispersal.

Example: A tomato is a fruit because it develops from the ovary and contains seeds.

Plant Anatomy

Root and Stem Cross Sections

Plant anatomy involves the study of internal structures, especially roots and stems, which can be distinguished in cross section.

• Root Cross Section: Central vascular cylinder (stele), surrounded by cortex and epidermis.

• Stem Cross Section: Vascular bundles arranged in a ring (eudicots) or scattered (monocots), with cortex and pith.

Monocots vs Eudicots

• Monocots: One cotyledon, parallel leaf veins, scattered vascular bundles.

• Eudicots: Two cotyledons, net-like leaf veins, vascular bundles in a ring.

Feature	Monocot	Eudicot
Number of Cotyledons	1	2
Leaf Venation	Parallel	Net-like
Vascular Bundle Arrangement	Scattered	Ring
Root System	Fibrous	Taproot

Example: Corn is a monocot; beans are eudicots.

Fungi

Characteristics and Identification

Fungi are eukaryotic organisms that include molds, yeasts, and mushrooms. They play key roles as decomposers and in symbiotic relationships.

• Key Structures: Hyphae (filamentous cells), mycelium (network of hyphae), spores, fruiting bodies (e.g., mushrooms).

• Phyla/Genus:

  • Zygomycota: Bread molds (Rhizopus).

  • Ascomycota: Sac fungi (Aspergillus, Penicillium).

  • Basidiomycota: Club fungi (mushrooms, Agaricus).

Example: Rhizopus produces sporangia at the tips of upright hyphae.

Additional info: Academic context and examples have been added to expand on the brief points in the original study guide, ensuring the notes are self-contained and suitable for exam preparation.