Lecture Notes on Environmental Biology, Botany, and Microbiology

Flashcards based on lecture notes about terrestrial and aquatic systems, nutrient cycles, conservation biology, bacteria, archaea, protists, plant diversity, plant structure, and plant responses.

How do temperature and moisture levels affect the productivity of terrestrial systems?

Warm/moist climates (tropical) are more productive than cold/dry climates (tundras) and hot/dry climates (deserts).

What are the limiting nutrients that restrict growth in terrestrial systems?

Nitrogen and phosphorus are key nutrients that can limit plant growth in terrestrial systems.

What are the Standing Crops?

The total biomass of photosynthetic autotrophs at a given time.

What are the major ecosystems and their characteristics related to primary production?

Tropical rainforests, grasslands, estuaries, wetlands, coral reefs, and pelagic zones of oceans.

What limits primary production in aquatic systems?

Light and nutrients (nitrogen and phosphorus) are limiting factors in aquatic systems.

What is Eutrophication?

the process in which a body of water has an excess of nutrients present, leading to the excessive growth of algae and aquatic plants, which can deplete oxygen levels and harm the ecosystem

What is the energy transfer efficiency between trophic levels?

Only about 10% of energy transfers between trophic levels, with the rest lost as heat or waste.

What is production efficiency?

Percentage of energy used for growth and reproduction (excluding respiration and waste); amount of energy available to the next trophic level.

What is the biological importance of nitrogen?

Components of amino acids, proteins, and nucleic acids.

What are the forms of Nitrogen used by Living organisms such as plants and algae?

Plants/Algae - ammonium (NH4+), nitrate (NO3-).

What is Trophic Efficiency?

Percentage of energy transferred to the next level, includes energy lost to feces; typically 5% - 20%, averaging ~10%.

What drives chemical cycling, and what factors affect its rate?

Driven by decomposers; rate depends on temperature, moisture, and nutrients.

What is the biological importance and form of usage for water in nutrient cycles?

Essential to all organisms; liquid phase.

What are the major reservoirs for water?

Oceans (97%), glaciers and polar ice caps (2%), freshwater (1%).

What is the biological importance and form of usage for carbon?

Carbon-based organic molecules are essential to all organisms; CO2 (used for photosynthesis and sugar makeup)

What are the major reservoirs for carbon?

Fossil fuels/sedimentary rock, soil and sediment, plant and animal biomass, atmosphere

What are the major reservoirs for nitrogen?

Atmosphere (mainly used by bacteria that decompose it for heterotrophs; 80%), soil/sediments of aquatic environments, surface and groundwater, biomass.

What are the different processes of movements for nitrogen?

Bacterial Nitrogen Fixation converts ammonium (NH4+) to nitrite (NO2-) to nitrate (NO3-).

What is the biological importance and form of usage for phosphorus?

Major component of nucleic acids, phospholipids, ATP, bones and teeth; phosphate (PO4 3-), used by plants to synthesize organic compounds.

What are the major reservoirs for phosphorus?

Sedimentary rock of marine origin, desert soil, ocean water, organisms.

What is Bioremediation?

Using living organisms to remove or neutralize contaminants from soil and water.

What is Biological Augmentation?

The introduction of specific organisms or components into an environment to help repair a degraded system.

What is Restoration Ecology?

The scientific study and practice of actively repairing damaged or degraded ecosystems through human intervention to restore biodiversity and ecosystem functions.

What is Biomanipulation?

The deliberate manipulation of an ecosystem species composition to achieve a desired ecological outcome.

What is Conservation Biology?

An interdisciplinary field that seeks to preserve life on Earth by integrating studies in ecology, physiology, molecular biology, genetics, and evolutionary biology.

What is Extinction?

The permanent loss of a species.

What is Biodiversity?

The variation of life on Earth.

What is Genetic Diversity?

The variety of genes or alleles within a population, developed through adaptation.

What are Endangered Species?

Species at risk of extinction across all or a significant portion of their range.

What are Threatened Species?

Species likely to become endangered in the foreseeable future.

What is Ecosystem Diversity?

The variety of different ecosystems, including habitats, communities, and ecological processes.

Which is the most severe threat to biodiversity?

Habitat Loss (Most Severe).

What are Introduced (Invasive) Species?

Organisms moved by humans to environments where they did not naturally occur.

What is Overharvesting?

The process of harvesting organisms at rates that exceed their ability to repopulate.

What is Global Change?

Alterations to climate, atmospheric chemistry, and ecosystems that reduce Earth’s capacity to sustain life.

What is Extinction vortex?

The cycle where loss of genetic variation increases extinction risk.

What is Sustainable Development?

Economic development that meets present needs without limiting future generations' ability to meet theirs.

What is the Sustainable Biosphere Initiative?

Aims to define and acquire ecological information to manage and conserve Earth’s resources responsibly.

What are the characteristics of Bacteria?

unicellular organisms; can form colonies, peptidoglycan is in cell wall

What is peptidoglycan?

Polymer of sugars cross-linked by amino acids.

What is gram positive bacteria?

Simple, thick peptidoglycan wall.

What is gram negative bacteria?

Complex, thin peptidoglycan wall covered by a lipopolysaccharide (LPS) layer.

What are Endospores?

Resting/resistant form of bacteria.

What is the Capsule of bacteria?

Outer layer of polysaccharides & proteins.

What is the Fimbria of bacteria?

Hair-like extensions; interactions with the environment (substrate binding); variable in number.

What is the Pilus of bacteria?

Exchanges plasmid (not genomic) DNA.

What is the Flagella of bacteria?

Helical structures for movement; evolved through exaptation; analogous trait (differs from eukaryotic/archaeal flagella).

What is Transduction in bacteria?

Bacteriophage infects bacteria #1 and combines bacteria #1’s linear DNA with its own while replicating. This creates virions (new bacteriophages) that will infect bacteria #2 and transfer bacterial DNA from bacteria #1 to bacteria #2.

What is Transformation in bacteria?

Free linear DNA in the environment is taken by bacteria and incorporated into their own genome.

What is Conjugation in bacteria?

Direct contact via pilus allows for plasmid DNA transfer between two bacteria.

How do Photoautotrophs gain energy?

Energy from light.

How do Chemoautotrophs gain energy?

Energy from chemical compounds (oxidizing H₂S, NH₄⁺, Fe²⁺).

What are Heterotrophs?

Require organic nutrients to make organic compounds.

What are Obligate Aerobes?

Require oxygen; most prokaryotes.

What are Facultative Anaerobes?

Can live with or without oxygen (e.g., fermentation).

What are Obligate Anaerobes?

Poisoned by oxygen; use fermentation or anaerobic respiration; most nitrogen fixing bacteria.

What is the role of Alpha Proteobacteria?

Usually positive, associated with eukaryotic hosts.

What is the role of Beta Proteobacteria?

Involved in the nitrogen cycle → convert N₂ to NH₄ and back.

What is the role of Gamma Proteobacteria?

Usually negative, pathogenic (gut-related illnesses).

What are Spirochetes?

Helical or spiral shaped, gram negative → hard to kill.

What are Cyanobacteria?

Gram negative, photoautotrophs, oxygen producers.

What are the characteristics of Extremophiles?

Halophiles (salt) and Thermophiles (heat).

What are Methanogens?

Use CO₂ to oxidize H₂ and produce methane (odorless, colorless, flammable greenhouse gas).

Why is there No Prokaryotes = No Habitable Biosphere?

Prokaryotes act as decomposers and cycle nutrients throughout ecosystems, connecting all levels of the food chain

What is Bioremediation in relevance to bacteria?

Prokaryotes can be added into environments to remove toxins.

What is Recombination Bacteria in the ecosystem?

Manipulations to the simpler bacterial/prokaryotic genome to create useful proteins, hormones, vitamins, etc.

What are Protists?

Mainly unicellular eukaryotes with more structural and functional diversity than any other group of eukaryotes.

What is Primary Endosymbiosis?

Ancestral archaeal host (Lockiarcaeote) engulfed alphaproteobacteria → mitochondria → creation of all eukaryotes.

What is Secondary Endosymbiosis?

Eukaryote (host) engulfed red/green algae (symbionts).

What defines Excavata?

Defined by cytoskeletal features.

What defines SAR?

Diverse group, defined by DNA similarities.

What defines Archaeplastida?

Originated from symbiosis: heterotrophic protist + cyanobacteria.

What defines Unikonta?

Includes animals, fungi, and some protists.

What are Kinetoplastids?

Single large mitochondrion (DNA = kinetoplast).

What are Diatoms?

Major phytoplankton (photoautotrophs), silica (SiO₂) exoskeleton.

What encompasses Green Algae?

Two taxa: Charophytes (closest relatives to plants) and Chlorophytes (freshwater environments).

What are Amoebozoans?

Heterotrophs with lobe/tube-shaped pseudopodia.

What are Euglenids?

Photoautotrophs (phytoplankton), product of secondary endosymbiosis with green algae, toxin-producing blooms, biflagellate at one end.

What are Dinoflagellates?

Cellulose internal skeleton, two perpendicular flagella, bioluminescent, can produce toxic blooms (“red tides”).

What are Ciliates?

Predators using cilia to move/feed; two nuclei: Macronucleus (2n, asexual reproduction) and Micronucleus (n, sexual reproduction).

What are Radiolarians?

Threadlike pseudopodia for movement/feeding, silica-based skeletons, zooplankton in marine ecosystems.

What are Forams?

Carbonate-based porous skeletons, form mutualisms with dinoflagellates.

What is the ecological role of Protists as primary producers?

Perform 30% of world’s photosynthetic production.

How is the protist Ecological Roles related to Climate Impact?

Global warming threatens stramenopiles, alveolates, and dinoflagellates (release toxins).

How does the chronological events align for the plant and life ecosystem?

Small plants, fungi, and animals came next after cyanobacteria and protists.

What is the role of Plants?

Use carbon dioxide, produce oxygen and water, foundation of food chains (50% of earth’s primary production).

What does it means when Inclusion of chlorophyll α and b plants?

Chloroplasts in plants, green algae, dinoflagellates, euglenids.

What is Sporopollenin?

Secretion of a durable polymer that prevents desiccation of spores; adaption to allow life on land

What is Alternation of generations?

Sporophyte (diploid) → spores → gametophyte → gametes (haploid) → fertilization → zygote → sporophyte (diploid).

What do Multi cellular dependent embryos mean?

Embryos live inside and receive nutrients from maternal plant (embryophyte).

How is Apical meristems adapted for plants

Cells in apical roots grow into roots, cells in apical shoots grow toward sunlight

What are the Bryophytes (Nonvascular Plants)?

Mosses, liverworts, hornworts

What are the features of Bryophytes (Nonvascular Plants)?

Smallest, simplest extant plants; no roots or vascular systems → small size, dominant life stage is gametophyte.

What is the Significance of Moss?

Retains nitrogen, holds nitrogen-fixing cyanobacteria → primary succession inhabits extreme conditions.

What is the Significance of Bogs?

Contains 30% of earth’s soil-based carbon, prevent decomposition → plant material accumulates → releases CO2 → global warming.

What are the features for Vascular plants?

Life cycle dominated by sporophytes, presence of vascular systems, roots, and leaves, ferns are sporophytes, gametophytes live on or below ground; require water film for flagellated sperm.

What is Xylem?

Uses tracheids for water/nutrient movement. Lignin provides support.

What is Phloem?

Tubes transport sugars, amino acids, organic compounds.

What are the function of Root?

Anchor plant; greater water/nutrient absorption, support increased height.

What are the function of Leaves?

Surface area → sunlight capture; photosynthesis.