BIO 112 Final Exam BASU

Phylum Porifera: Functional Anatomy

No true tissues or organs; asymmetrical or radial; choanocytes (collar cells) create water flow; skeleton made of spicules or spongin.

Phylum Porifera: Habitat

Mostly marine; some freshwater.

Phylum Porifera: Life-style

Sessile filter feeders; water flows through body via ostia, spongocoel, and osculum.

Phylum Cnidaria: Functional Anatomy

Radial symmetry; diploblastic; cnidocytes with nematocysts; two body forms (polyp and medusa); gastrovascular cavity.

Phylum Cnidaria: Habitat

Mostly marine; some freshwater species like Hydra.

Phylum Cnidaria: Life-style

Carnivorous; some alternate between polyp and medusa; corals form symbiosis with algae (zooxanthellae).

Phylum Platyhelminthes: Functional Anatomy

Bilateral symmetry; triploblastic acoelomates; gastrovascular cavity; no circulatory/respiratory system; flame cells for excretion.

Phylum Platyhelminthes: Habitat

Aquatic and moist terrestrial environments.

Phylum Platyhelminthes: Life-style

Free-living scavengers (Planaria) or parasites (flukes, tapeworms); complex life cycles.

Phylum Mollusca: Functional Anatomy

Coelomate; head-foot, visceral mass, mantle; radula (except bivalves); open circulatory system (closed in cephalopods).

Phylum Mollusca: Habitat

Marine, freshwater, and terrestrial (e.g., snails).

Phylum Mollusca: Life-style

Grazers (snails), filter feeders (clams), active predators (squid, octopus); cephalopods highly intelligent.

Phylum Annelida: Functional Anatomy

Segmented body; coelomate; closed circulatory system; setae for movement; developed nervous and excretory systems.

Phylum Annelida: Habitat

Marine, freshwater, and moist terrestrial.

Phylum Annelida: Life-style

Earthworms are detritivores; leeches may be parasitic; polychaetes are often marine.

Phylum Nematoda: Functional Anatomy

Pseudocoelomates; unsegmented cylindrical body; complete digestive tract; cuticle molted; no circulatory/respiratory system.

Phylum Nematoda: Habitat

Aquatic, terrestrial, or parasitic.

Phylum Nematoda: Life-style

Free-living decomposers or parasites (e.g., Trichinella, Ascaris).

Phylum Arthropoda: Functional Anatomy

Segmented body; jointed appendages; chitinous exoskeleton; open circulatory system; specialized sensory structures.

Phylum Arthropoda: Habitat

Extremely diverse—marine, freshwater, terrestrial.

Phylum Arthropoda: Life-style

Herbivores, predators, parasites, scavengers; many undergo metamorphosis; most diverse animal phylum.

Phylum Echinodermata: Functional Anatomy

Adult radial symmetry; calcareous endoskeleton; water vascular system with tube feet; nerve ring without brain.

Phylum Echinodermata: Habitat

Exclusively marine.

Phylum Echinodermata: Life-style

Slow-moving or sessile; sea stars are predators; sea cucumbers are detritivores.

Q: What are the key characteristics of vertebrates (Craniata)?

A: Vertebral column (replaces notochord); cranium; endoskeleton of cartilage or bone; pronounced cephalization; neural crest cells; closed circulatory system; complex organ systems.

Q: What are agnathans and which organisms are included?

A: Jawless vertebrates; includes extinct ostracoderms and living hagfish and lampreys.

Q: What are characteristics of hagfish?

A: Marine scavengers; cartilaginous skull; no vertebrae; produce slime as defense.

Q: What are characteristics of lampreys?

A: Parasitic or filter-feeding; cartilaginous vertebrae; larval stage resembles lancelets.

Q: What are gnathostomes?

A: Jawed vertebrates with paired fins and enhanced sensory systems.

Q: How did jaws evolve in gnathostomes?

A: From modifications of pharyngeal arches that supported gill slits.

Q: What are characteristics of Chondrichthyes?

A: Cartilaginous skeleton; placoid scales; paired fins; internal fertilization; no swim bladder; lateral line system; electroreception via Ampullae of Lorenzini.

Q: Examples of Chondrichthyes?

A: Sharks, rays, and skates.

Q: What are Osteichthyes?

A: Bony fishes with a bony endoskeleton, swim bladder, operculum covering gills, and mucus-covered scales.

Q: What are Actinopterygii?

A: Ray-finned fishes; most diverse vertebrate group; fins supported by long, flexible rays.

Q: What are Sarcopterygii?

A: Lobe-finned fishes with fleshy, muscular fins with bones; includes coelacanths, lungfishes, and tetrapod ancestors.

Q: What are key tetrapod adaptations?

A: Four limbs with digits; stronger vertebral column; neck; fused pelvic girdle.

Q: What are Amphibians?

A: Vertebrates with aquatic larvae and terrestrial adults; cutaneous respiration; 3-chambered heart; shell-less eggs laid in water.

Q: Examples of Amphibians?

A: Frogs, toads, salamanders, caecilians.

Q: What are amniotes?

A: Vertebrates that produce an amniotic egg adapted for reproduction on land.

Q: What are the four membranes of the amniotic egg and their functions?

A: Amnion (cushions embryo); Chorion (gas exchange); Yolk sac (nutrients); Allantois (waste disposal).

Q: What are key reptile adaptations?

A: Keratinized scales; efficient kidneys; lungs; shelled amniotic eggs; ectothermic.

Q: Examples of reptiles?

A: Turtles, lizards, snakes, crocodiles.

Q: What are key adaptations of birds (Aves)?

A: Feathers; hollow bones; air sacs; beak (no teeth); 4-chambered heart; endothermy; hard-shelled eggs; parental care.

Q: What are key characteristics of mammals?

A: Hair; mammary glands; endothermy; diaphragm; 4-chambered heart; differentiated teeth.

Q: What are monotremes?

A: Egg-laying mammals like the platypus; lack nipples.

Q: What are marsupials?

A: Pouched mammals with short gestation and external development in a pouch (e.g., kangaroos).

Q: What are eutherians?

A: Placental mammals with long gestation and a complex placenta; young are well-developed at birth.

Q: What are key primate traits?

A: Grasping hands and feet; binocular vision; large brain; flat nails; parental care; social behavior.

Q: What defines anthropoids?

A: Monkeys, apes, and humans; larger brains and more complex behavior.

Q: What are key hominin traits?

A: Bipedalism; enlarged brain; tool use; cultural evolution.

Homology

A similarity due to shared ancestry; structures may differ in function but have common origins.

Homologous Structures

Structures with a common evolutionary origin; may serve different functions in modern species.

Vestigial Structures

Remnants of features that served a function in the organism's ancestors.

Convergent Evolution

Independent evolution of similar features in species of different lineages due to similar environments.

Scientific Theory

A well-substantiated explanation of some aspect of the natural world, based on facts, tested hypotheses, and laws.

Darwin and Wallace

Both proposed evolution by natural selection; Darwin focused on descent with modification, Wallace worked in Southeast Asia.

Wallace's Line

A biogeographic boundary separating species with Asian and Australian affinities due to deep water barrier.

Biological Species Concept

A species is a group of populations that can interbreed and produce viable, fertile offspring; reproductively isolated from others.

Prezygotic Barriers

Prevent mating or fertilization (e.g., habitat, temporal, behavioral, mechanical, gametic isolation).

Postzygotic Barriers

Prevent viable, fertile offspring after fertilization (e.g., hybrid inviability, sterility, breakdown).

Directional Selection

Favors one extreme phenotype, shifting the average in one direction.

Disruptive Selection

Favors both extreme phenotypes over intermediate phenotypes.

Stabilizing Selection

Favors intermediate phenotypes and reduces variation.

Natural Selection

Differential survival and reproduction based on inherited traits; leads to adaptation.

Genetic Drift

Random changes in allele frequencies, especially in small populations.

Founder Effect

A few individuals establish a new population, leading to reduced genetic variation.

Bottleneck Effect

Drastic reduction in population size reduces genetic diversity.

Gene Flow

Movement of alleles between populations; can increase or decrease genetic diversity.

Hardy-Weinberg Equation

p + q = 1 (allele frequencies); p² + 2pq + q² = 1 (genotype frequencies); describes a non-evolving population.

Phylogenetic Tree

Diagram showing evolutionary relationships; branches represent common ancestry.

Cladistics

A classification system based on shared derived characters (synapomorphies).

Virus

A non-cellular infectious agent with nucleic acid (DNA or RNA) in a protein coat (capsid); sometimes with envelope.

Lytic Cycle

Viral replication cycle where the host cell is immediately used to produce new viruses and then lysed.

Lysogenic Cycle

Viral DNA integrates into host genome and replicates with it before entering lytic cycle.

Gram-Positive Bacteria

Thick peptidoglycan wall, no outer membrane, stains purple in Gram stain.

Gram-Negative Bacteria

Thin peptidoglycan wall, outer membrane present, stains pink; more resistant to antibiotics.

Oxygen Revolution

2.7 billion years ago; oxygen accumulated in atmosphere due to cyanobacterial photosynthesis.

Photoautotrophs

Use light energy and CO₂ to produce food (e.g., plants, cyanobacteria).

Chemoheterotrophs

Obtain energy and carbon from organic molecules (e.g., animals, fungi).

Chemolithoautotrophs

Use inorganic chemicals for energy and CO₂ as carbon source (e.g., deep-sea bacteria).

Photoheterotrophs

Use light for energy but require organic carbon (e.g., some bacteria).

Diatoms

Photosynthetic protists with silica shells; major component of phytoplankton.

Brown Algae

Multicellular protists (e.g., kelp); have chlorophyll and accessory pigments; contain algin.

Oomycetes

Fungus-like protists; decomposers or pathogens like potato blight.

Slime Molds

Amoebozoans that live as single cells or form multicellular structures; feed on detritus.

Gymnamoebas

Free-living amoebas that use pseudopodia; found in soil and water.

Entamoebas

Parasitic amoebas, including human pathogens like Entamoeba histolytica.

Fungal Cell Structure

Eukaryotic cells with chitin cell walls; store energy as glycogen; have ER, Golgi, mitochondria.

Fungal Mating Types

Fungi reproduce via (+) and (-) mating types; not male/female.

Plasmogamy

Fusion of cytoplasm from two parent mycelia.

Heterokaryotic Stage

Cells contain two or more genetically distinct nuclei.

Karyogamy

Fusion of nuclei to form a diploid zygote, followed by meiosis to form spores.

Bryophytes

Nonvascular plants with dominant gametophyte stage; includes mosses, liverworts, and hornworts.

Bryophyte Adaptations

Small size, water-dependent sperm; important for soil formation and carbon storage.

SVPs

Seedless vascular plants; dominant sporophyte, independent gametophyte; true roots and leaves.

Xylem

Conducts water and minerals; contains lignin for strength.

Phloem

Transports sugars and nutrients.

Monocots

Angiosperms with 1 cotyledon, parallel veins, scattered vascular tissue, fibrous roots, floral parts in 3s.

Eudicots

Angiosperms with 2 cotyledons, net-like veins, ringed vascular tissue, taproot, floral parts in 4s or 5s.

Protostome Development

Spiral, determinate cleavage; mouth from blastopore; coelom from mesoderm splitting.