Biology Lecture Notes Review

Flashcards covering key vocabulary and concepts from the biology lecture notes.

Biodiversity

The variety of life in all its forms, levels, and combinations, including genetic, species, and ecosystem diversity.

Systematics

The scientific study of the diversity of organisms and their evolutionary relationships, including taxonomy and phylogenetics.

Phylogenetic Tree

A diagram that represents evolutionary relationships among organisms, with branches representing lineages, nodes representing common ancestors, and tips representing current or extinct species.

Monophyletic Group (Clade)

Includes a common ancestor and all its descendants.

Paraphyletic Group

Includes a common ancestor and some (but not all) of its descendants.

Polyphyletic Group

Does not include the common ancestor of all members; grouped based on similar traits that evolved independently (convergent evolution).

Domains that Prokaryotes Belong To

Bacteria and Archaea

Prokaryotic Cell Shapes

Coccus (spherical), Bacillus (rod-shaped), Spirillum (spiral)

Flagella

Long, whip-like tail used for movement.

Pili

Hair-like structures used for attachment and conjugation (DNA exchange).

Fimbriae

Shorter and more numerous than pili; used mainly for sticking to surfaces

Types of Prokaryotes Based on Metabolism

Photoautotrophs, Chemoautotrophs, Photoheterotrophs, Chemoheterotrophs

Ecological Roles of Prokaryotes

Decomposers, Nitrogen-fixers, Pathogens, Symbionts, Extremophiles

Important Diseases Caused by Bacteria

Tuberculosis, Lyme Disease, Cholera, Tetanus

Why Prokaryotes Are Not Considered a Single Taxon

Archaea are more closely related to Eukarya than to Bacteria, meaning 'prokaryotes' include two separate evolutionary lineages.

How Prokaryotes Are More Diverse Than Eukarya

They have more types of metabolism, are found in more extreme environments, and have existed longer than eukaryotes.

Core Features of Eukaryotes

Have a nucleus, membrane-bound organelles, and a cytoskeleton.

Mitosis

Allows for growth and asexual reproduction (cell division with genetic consistency).

Meiosis

Produces gametes (sex cells) and introduces genetic variation.

Levels of Organization in Eukaryotes

Unicellular, Colonial, True Multicellularity

Endosymbiotic Theory

Mitochondria came from an aerobic bacterium, and chloroplasts came from a photosynthetic cyanobacterium.

Why Protists Are Not a “Good” Kingdom

It is polyphyletic and paraphyletic.

The Four Major Clades of Protists

Excavata, SAR (Stramenopiles, Alveolates, Rhizaria), Archaeplastida, Unikonta

General Characteristics of Protists

Usually unicellular or colonial; grouped by ecological role as protozoans, algae, or fungus-like organisms.

Ecological Niches of Protists

Algae generate a large portion of Earth's oxygen.

Phyla for Common Pathogenic Protists

Giardia, Trichomonas, Trypanosoma, Gymnodinium, Plasmodium, Entamoeba

The Crown Eukaryotes

Plants, Animals, Fungi

Why Crown Eukaryotes are considered 'good' kingdoms

Monophyletic, holophyletic and have distinctive shared traits.

Shared Traits of Plants

Cellulose walls, chloroplasts

Shared Traits of Animals

Multicellular, heterotrophic, lack cell walls

Shared Traits of Fungi

Chitin walls, decomposers, absorptive heterotrophy

Evolutionary Trends in Plantae

Evolution of vascular tissue, seeds, and flowers and from aquatic to terrestrial life

Evolutionary Trends in Animalia

Increasing complexity: tissues, organs, symmetry, segmentation and cephalization (development of a head)

Evolutionary Trends in Fungi

Shift to land, symbioses, and diversity of reproductive strategies

Shared Traits of All Plants

Alternation of generations (Gametophyte and Sporophyte), Photoautotrophic, Multicellular with tissues, Embryo retained within female tissue.

Evolutionary Trends in Plant Lineages

Gametophyte → Sporophyte dominance, Nonvascular → Vascular, Seedless → Seeds, Naked seeds → Seeds in fruits

Bryophyta (Mosses) Characteristics

Gametophyte dominant, no vascular tissue, moist

Pterophyta (Ferns) Characteristics

Sporophyte dominant, has vascular tissue, reproduce via spores

Coniferophyta (Conifers) Characteristics

Sporophyte dominant, vascular tissue, Produce seeds, but naked

Magnoliophyta (Angiosperms) Characteristics

Sporophyte dominant, vascular tissue, Seeds enclosed in fruits, Flowers for pollination

Key Features of Fungi

Zygotic meiosis: The only diploid stage is the zygote, Heterotrophic by assimilation, Reproduce with spores

Evolutionary direction in Fungi

From coenocytic (no septa) → septate (divided by walls), Present in ancestral forms→ lost in most fungi, Early fungi mostly microscopic → some macroscopic fruiting bodies

Key Characteristics of Chytridiomycota

Only fungi with flagellated spores (zoospores); mostly aquatic

Key Characteristics of Zygomycota

Mostly coenocytic hyphae; form zygosporangia in sexual reproduction

Key Characteristics of Glomeromycota

Form arbuscular mycorrhizae with plants; vital for root symbiosis

Key Characteristics of Ascomycota

Sac fungi; spores in asci; includes yeasts, molds, morels

Key Characteristics of Basidiomycota

Club fungi; spores on basidia; includes mushrooms, puffballs

Lichens

Symbiosis between a fungus and a photosynthetic partner

Imperfect Fungi (Deuteromycota)

Fungi without a known sexual stage

Gametic meiosis

Diploid-dominant life cycle and only haploid cells are gametes

Heterotrophic by ingestion

Animals consume organic material and digest it internally

Multicellular in animals

With cellular, tissue, or organ-level organization

Trend in Symmetry of animals

Asymmetry → Radial symmetry → Bilateral symmetry

Trend in Germ Layers of animals

Diploblastic (2 layers) → Triploblastic (3 layers)

Trend in Body Cavity (Coelom) of animals

Acoelomate → Pseudocoelomate (hemocoelomate) → Coelomate

Diploblastic animals have

Ectoderm and endoderm only

Triploblastic animals have

Ectoderm, mesoderm, and endoderm

Acoelomate description

No body cavity

Pseudocoelomate description

Body cavity not fully lined with mesoderm

Coelomate description

True coelom fully lined by mesoderm

Phylum Ctenophora (Comb jellies) Characteristics

Radial symmetry, Diploblastic, rows of cilia for movement

Phylum Porifera (Sponges) Characteristics

Asymmetrical or radial, Cellular-level organization, Filter feeders using choanocytes and no nervous system

Phylum Cnidaria (Jellyfish, corals) Characteristics

Radial symmetry, Diploblastic, True tissues but no organs, Have cnidocytes

Bilateral symmetry

Left-right symmetry with a head (cephalization)

Triploblastic in Bilateria

Three germ layers (ectoderm, mesoderm, endoderm)

Protostomes

"Mouth first" — blastopore becomes the mouth

Deuterostomes

"Mouth second" — blastopore becomes the anus

Lophotrochozoa

Non-molting protostomes

Ecdysozoa

Molting protostomes

Animals in Lophotrochozoa have either

Have a lophophore (ciliated feeding structure) or pass through a trochophore larval stage

Phylum Platyhelminthes (Flatworms) Characteristics

Acoelomate, Dorsoventrally flattened, Incomplete gut

Phylum Nemertea (Ribbon worms) Characteristics

Proboscis housed in a rhynchocoel and Complete digestive tract

Phylum Rotifera (Rotifers) Characteristics

Pseudocoelomates and Ciliated corona for feeding and locomotion

Phylum Gastrotricha Characteristics

Pseudocoelomates or acoelomates and Ciliated, microscopic

Phylum Annelida (Segmented Worms) Characteristics

True coelom, Segmented body, Closed circulatory system

Phylum Mollusca Characteristics

Coelomates; Body plan: head-foot, visceral mass, mantle

Polyplacophora (chitons) Characteristics

8-plated shells

Gastropoda (Snails and Slugs) Characteristics

Snails, slugs — torsion during development

Bivalvia (Clams and Oysters) Characteristics

Clams, oysters — two-part shells, filter feeders

Cephalopoda (Squids and Octopuses) Characteristics

Squids, octopuses — smart, closed circulatory system, tentacles

Phylum Phoronida Characteristics

Tube-dwelling marine worms, U-shaped gut, Secrete chitinous tubes

Phylum Ectoprocta (Bryozoans) Characteristics

Colonial, Each zooid has its own lophophore and protective casing

Phylum Brachiopoda Characteristics

Bivalve-like shell, but dorsal-ventral, not left-right

Key Traits of Ecdysozoa

All undergo ecdysis — molting of a cuticle or exoskeleton

Phylum Nematoda (Roundworms) Characteristics

Pseudocoelomate, unsegmented, Complete digestive tract

Phylum Nematomorpha (Horsehair worms) Characteristics

Parasitic larvae in arthropods; free-living as adults

Phylum Cycliophora Characteristics

Tiny, marine organisms living on lobster mouthparts

Phylum Arthropoda – “Jointed Feet” Characteristics

Segmented body with jointed appendages

Extinct Trilobita

Extinct marine arthropods with three-lobed body

Subphylum: Chelicerata Characteristics

Chelicerae (mouthparts) instead of mandibles and No antennae

Subphylum: Mandibulata Characteristics

Possess mandibles (jaw-like mouthparts) and Usually have antennae

Key Traits of Chelicerata

Chelicerae, no antennae

Key Traits of Mandibulata

Mandibles, antennae

Key Developmental Traits of Deuterostomes

Blastopore becomes the anus

Key Traits of Echinodermata

Radial symmetry as adults (but bilaterally symmetric larvae)

Chordate Shared Traits

Notochord, Dorsal hollow nerve cord, Pharyngeal gill slits

Subphylum: Urochordata (Tunicates) Characteristics

Larvae show all 5 chordate traits

Subphylum: Cephalochordata (Lancelets) Characteristics

Simple, fish-like body plan with all chordate features

Subphylum: Vertebrata (Craniata) Characteristics

Have a vertebral column and Cranium protecting the brain

Class Agnatha Description

Jawless fish; no paired fins