Comprehensive Biology Review: Botany, Mycology, and Evolutionary Mechanics

Angiosperms Defined: A plant is classified as an angiosperm primarily because it produces flowers. While other traits like leaves and long stems may exist, the presence of flowers is the distinguishing reproductive characteristic.
Seed Coverage:
- Gymnosperms: The term literally translates to "naked seeds." These seeds are not enclosed in an ovary (e.g., those found in cones).
- Angiosperms: These are characterized by "covered seeds," where the seeds are protected within an ovary or fruit.

Xylem: This specialized vascular tissue is responsible for the upward transport of water and minerals throughout the plant.
Phloem: This tissue is the counterpart to xylem and is responsible for transporting minerals and sugars (photosynthates), often involving downward or multi-directional flow to distribute nutrients to the rest of the plant.

Monocots (Monopods):
- Floral Symmetry: Petals occur in multiples of $3$ .
- Leaf Venation: Leaves possess parallel veins.
- Root System: Typically characterized by a fibrous root system (denoted as "M for monocots, F for fibrous").
- Internal Stem Structure: Vascular bundles are scattered throughout the stem when cut in half.
Dicots (Dipods/Dicotyledons):
- Floral Symmetry: Petals occur in multiples of $4$ or $5$ .
- Leaf Venation: Leaves feature a central vein with other veins branching out (net-like or fanned out).
- Root System: Typically characterized by a taproot system (denoted as "D for dicot, T for taproot").
- Internal Stem Structure: Vascular bundles are organized in a circular manner when the stem is cut in cross-section.

Carpel: This is the all-encompassing female reproductive portion of the plant. It includes:
- Stigma: The receptive tip that captures pollen.
- Style: The stalk that connects the stigma to the ovary.
Stamen: The male reproductive portion of the plant. It includes:
- Anther: The specific structure that produces and releases pollen.
- Filament: The stalk supporting the anther.
Sepals: These are the structures that directly enclose and protect the flower bud before it opens.

Auxin: This hormone is essential for cell growth via the activation of expansins. The process involves:
1. Auxin attaches to a plant cell.
2. It activates proton pumps to pump protons into the cell wall.
3. The resulting acidity causes expansin proteins to relax and expand, allowing the cell to grow.
Cytokinins: These hormones trigger the specific step of cell division known as cytokinesis, where the cytoplasm separates.
Gibberellins (GIBB): Predominantly released during the spring season. These hormones are involved in seedling growth, root development, and leaf expansion.
Ethylene: Known as the "stress" or "injury" molecule, typically released during the fall season. Its functions include:
- Fruit ripening.
- Leaf abscission.
- Triple Response: Helps roots navigate obstacles through lateral growth (thickening of the stem, slowing of elongation, and horizontal growth).
Abscisic Acid (ABA): This hormone is released more frequently during the winter season and is generally associated with seed dormancy and drought tolerance.

Response to Flooding: To survive anaerobic conditions during floods, plants break down the walls of smaller tubes to create large internal pockets called air tubes. These structures maximize the amount of air the plant can store.
Thigmotropism: Growth or movement in response to touch (not to be confused with temperature).
Thermotropism: Growth or movement in response to temperature.
Gravitropism: Growth in response to gravity (roots growing down, shoots growing up).
Statoliths: These are dense, starch-filled plastids located within gelatinous substances in plant cells. They shift in response to gravity, helping the plant sense "down" versus "up" for proper root orientation.

Circadian Rhythm: Plants determine their biological clocks by measuring the length of the night, rather than the length of the day.
Red Light vs. Far-Red Light:
- Red Light: Associated with direct sunlight. Detecting red light promotes seed germination and sprouting.
- Far-Red Light: Associated with shadow or shade. Detecting far-red light (shade) generally inhibits germination or signals a lack of growth.

Phyla of Fungi:
- Ascomycota: Known as sac fungi.
- Basidiomycota: Known as club fungi.
Mycorrhizae: A mutualistic association between fungi and plant roots. The name is derived from "myco" (fungi) and "rizae" (roots).
Penicillin: A well-known antibiotic derived from fungi that is effective against bacteria.

Reproductive Isolations:
- Habitat Isolation: Species live in different areas and do not meet.
- Gametic Isolation: Sperm and eggs are incompatible.
Post-Zygotic Barriers:
- Reduced Hybrid Viability: The hybrid offspring's survival span or lifespan is significantly impaired.
- Reduced Hybrid Fertility: The hybrid organism is healthy but sterile (e.g., it does not produce functional sperm or eggs).
- Hybrid Breakdown: The first generation is fertile, but the second generation is sterile or weak.

Cyanobacteria: Photosynthetic bacteria characterized by a green-blue pigment.
Land Snails: Belong to the class Gastropoda.
Cephalopoda: A class of mollusks including octopuses and squids (characterized by distinct head structures).
Heterocercal Tails: A specific tail structure found in Chondrichthyes (cartilaginous fish like sharks), distinguishing them from bony fish.
Hornworts: A specific phylum that requires further study regarding its classification and characteristics.

Exam Structure: The final consists of $50$ questions total. There are $25$ multiple-choice questions (Part A and B) that are evenly distributed across the $24$ to $25$ lecture topics/chapters covered during the semester.
Question Weight: There are approximately $2$ questions per lecture topic.
Study Strategy: Students should not only memorize specific quiz questions but study the broader topics they cover, as the instructor may "flip" or switch details (e.g., testing phloem instead of xylem).

Student Question: Does anyone know how you find an angiosperm being an angiosperm?
Instructor Response: Flowers. That is the correct answer. It is practically "flowerified."
Student Question: What is the phylum of photosynthetic bacteria?
Instructor Response: Cyanobacteria.
Student Question: Is a hybrid that has no sperm or eggs an example of fertility issues?
Instructor Response: Yes, that is reduced hybrid fertility.
Student Question: Are the questions evenly distributed?
Instructor Response: Yes, they are evenly distributed between the $25$ topics, with roughly two questions per topic. Review the general information; don't just memorize the specific quiz questions.