Bio II Exam 2

Key Concepts from Chapters 16-19

Chapter 16: Microbial Life: Prokaryotes and Protists

Prokaryotes (16.1-16.11)

  • Diversity and Features: Prokaryotes are unicellular organisms that lack a nucleus. They are incredibly diverse and abundant, playing critical roles in ecosystems. They can form various shapes (bacilli, cocci, spirilla) and possess different cell wall compositions, mainly Gram-positive or Gram-negative.

  • Rapid Adaptation: Prokaryotes can adapt quickly to environmental changes due to their short generation times and horizontal gene transfer, allowing them to share beneficial traits rapidly.

  • Nutritional Diversity: They utilize various energy and carbon sources, classified as autotrophs (photoautotrophs and chemoautotrophs) or heterotrophs (chemoheterotrophs).

  • Biofilms: These are communities of microorganisms that stick to surfaces, surrounded by a protective matrix. They offer advantages like increased resistance to antibiotics and environmental stresses.

  • Environmental Cleanup: Prokaryotes like bacteria are used in bioremediation to degrade pollutants in the environment.

  • Three Domains of Life: The three domains are Archaea, Bacteria, and Eukarya, distinguished based on genetic and biochemical differences.

  • Archaea Classification: Archaea are categorized into extremophiles, including extreme halophiles (salt lovers), extreme thermophiles (heat lovers), and methanogens (methane producers), each thriving in harsh environments.

  • Bacterial Subgroups: Bacteria are divided into five subgroups - Proteobacteria, Chlamydias, Spirochetes, Cyanobacteria, and Gram-positive bacteria, each with unique characteristics and habitats.

  • Exotoxins vs. Endotoxins: Exotoxins are toxins secreted by bacteria (e.g., botulinum toxin), while endotoxins are components of the Gram-negative bacterial cell wall (e.g., lipopolysaccharides) that can elicit strong immune responses.

  • Koch’s Postulates: These are four criteria used to establish a causative link between a microbe and a disease. Barry Marshall famously demonstrated that Helicobacter pylori could cause gastritis by fulfilling these postulates.

Vocabulary

  • Archaea

  • bacilli

  • Bacteria

  • biofilm

  • bioremediation

  • chemoautotroph

  • chemoheterotroph

  • chlamydias

  • cocci

  • cyanobacteria

  • endospore

  • endotoxin

  • exotoxin

  • extreme halophile

  • extreme thermophile

  • fimbriae

  • Gram stain

  • gram-positive bacteria

  • metagenomics

  • methanogens

  • microbiome

  • microbiota

  • pathogens

  • peptidoglycan

  • photoautotroph

  • photoheterotroph

  • proteobacteria

  • spirochetes

  • symbiosis

Protists (16.12-16.19)

  • Types of Protists: Protists are a diverse group of eukaryotic microorganisms, categorized based on their mode of nutrition into photoautotrophs (algae) and heterotrophs (protozoa).

  • Monophyletic Supergroups: They are classified into four supergroups: Excavata, SAR (Stramenopila, Alveolata, Rhizaria), Archaeplastida (red and green algae), and Unikonta, each with distinct characteristics and evolutionary relationships.

  • Supergroup SAR: This includes diatoms, brown algae, and ciliates, which share certain features like specific types of chloroplasts or cellular structures.

  • Fossil Fuels: Fossil fuels primarily consist of ancient organic matter, including decomposed protists such as phytoplankton, which accumulated over millions of years.

  • Life Cycle of Ulva: Ulva, or sea lettuce, exhibits alternation of generations, alternating between haploid gametophyte and diploid sporophyte stages, showcasing the complexity of protist life cycles.

  • Ancestors of Multicellular Organisms: Early protists are considered ancestors of multicellular organisms, providing insights into the evolution of complex life forms.

Vocabulary

  • algae

  • alternation of generations

  • Alveolata

  • amoebas

  • amoebozoans

  • Archaeplastida

  • brown algae

  • cellular slime molds

  • ciliates

  • diatoms

  • dinoflagellates

  • Excavata

  • foraminiferans

  • gametophyte

  • green algae

  • kelp

  • mixotrophs

  • parasites

  • plasmodial slime mold

  • plasmodium

  • protists

  • pseudopodia

  • radiolarians

  • red algae

  • Rhizaria

  • SAR

  • sporophytes

  • Stramenopila

  • Unikonta

  • water molds

Chapter 17: The Evolution of Plant and Fungal Diversity

Plant Evolution and Diversity (17.1-17.2)

  • Adaptations for Land: Key adaptations include the development of a cuticle to prevent water loss, modifications in reproductive structures to cope with terrestrial environments, a vascular system for efficient nutrient and water transport, and mechanisms like stomata for gas exchange.

  • Key Events in Evolutionary History: Major events include the colonization of land, the emergence of seeds, and the development of flowers, which facilitated reproductive diversification and species proliferation.

  • Main Lineages Comparison: Bryophytes (mosses) are non-vascular; seedless vascular plants (ferns) have vascular tissue but no seeds; gymnosperms (conifers) produce seeds without flowers; angiosperms (flowering plants) have seeds within fruits, showcasing evolutionary advancements.

Vocabulary

  • angiosperms

  • apical meristems

  • bryophytes

  • embryophytes

  • gametangia

  • gymnosperms

  • lignin

  • phloem

  • pollen grains

  • seed

  • seedless vascular plants

  • sporangia

  • spore

  • vascular plants

  • vascular tissue

  • xylem

Alternation of Generations and Plant Life Cycles (17.3-17.11)

  • Life Cycle Comparison: Mosses exhibit a dominant gametophyte stage, while ferns demonstrate a dominant sporophyte form, highlighting differences in reproductive strategies.

  • Formation of Fossil Fuels: Fossil fuels, including coal, oil, and natural gas, form from ancient plant matter (especially ferns and seed plants) subjected to heat and pressure over geological time.

  • Pollen and Seeds: These adaptations enable reproduction without water and facilitate the spread of plant species across vast distances.

  • Flower Structure: Flowers possess parts including sepals, petals, stamens (male), and carpels (female), each performing crucial roles in reproduction and attracting pollinators.

  • Angiosperm Life Cycle Stages: They undergo meiosis to produce spores, fertilization to form zygotes, and seed development, promoting genetic diversity.

  • Seed Dispersal Adaptations: Angiosperms have evolved various mechanisms, such as wind, water, and animal dispersal, to ensure the spread of seeds for colonization.

  • Food Sources: Many angiosperms, such as grains (wheat, rice) and fruits (apples, berries), form the basis of human diets and agriculture.

  • Pollinator Attraction: Flowers use color, scent, and nectar to entice pollinators, facilitating cross-pollination and genetic diversity.

  • Habitat Destruction Effects: Loss of habitats can lead to decreased plant diversity and extinction, impacting ecosystems reliant on diverse plant life.

Vocabulary

  • alternation of generations

  • gametophyte

  • sporophyte

  • fossil fuels

  • pollination

  • ovules

  • seed coat

  • sepals

  • petals

  • stamens

  • anther

  • carpel

  • ovary

  • germinates

  • fruit

Diversity of Fungi (17.12-17.19)

  • Main Traits: Fungi are characterized by their eukaryotic cell structure, cell walls made of chitin, and heterotrophic mode of nutrition, absorbing nutrients from their environment.

  • Life Cycles: Fungi can reproduce asexually (via spores or budding) and sexually (by fusion of hyphae), leading to genetic variation.

  • Five Groups of Fungi: These groups include Chytridiomycetes (aquatic fungi), Zygomycetes (common molds), Ascomycetes (sac fungi), Basidiomycetes (club fungi), and Glomeromycetes (mycorrhizal fungi), each having unique reproductive strategies and ecological roles.

  • Ecological Benefits: Fungi act as decomposers, nutrient recyclers, and mutualistic partners (e.g., mycorrhizae with plants), enhancing soil health and plant growth.

  • Practical Uses: Fungi are essential in food production (bread, beer) and pharmaceuticals (antibiotics like penicillin), showcasing their importance in human society.

  • Lichens Structure: Lichens are symbiotic associations between fungi and photosynthetic organisms (algae or cyanobacteria), enabling them to thrive in harsh environments.

  • Mycorrhizae Evolution: Evidence suggests that mycorrhizal fungi formed mutualistic relationships with early land plants, aiding their nutrient uptake during the colonization of land.

  • Parasitic Fungi: Certain fungi like rusts and smuts can adversely affect plant and animal health, highlighting the duality of fungi as both beneficial and harmful organisms.

Vocabulary

  • absorption

  • ascomycetes

  • basidiomycetes

  • chitin

  • chytrids

  • club fungi

  • fungi

  • glomeromycetes

  • heterokaryotic stage

  • hyphae

  • imperfect fungi

  • lichens

  • mold

  • mycelium

  • mycorrhiza

  • parasites

  • sac fungi

  • yeast

  • zygomycetes

Chapter 18: The Evolution of Invertebrate Diversity

Animal Evolution and Diversity (18.1-18.4)

  • Defining Characteristics: Animals are multicellular, heterotrophic organisms with specialized tissues, including muscle and nervous tissues, enabling complex movement and sensory perception.

  • Life Cycle Stages: Most animals undergo several stages from zygote to adulthood, with early embryonic developments like cleavage and gastrulation forming germ layers.

  • Embryonic Layers: The three layers include the ectoderm (outer layer), mesoderm (middle layer), and endoderm (inner layer), contributing to organ systems.

  • Animal Diversification: Diversification began around 600 million years ago during the Cambrian explosion, resulting in a variety of body plans and niches.

  • Body Plans: Body plans can be radial (e.g., cnidarians) or bilateral (e.g., arthropods), influencing symmetry and organ placement.

  • Protostomes vs. Deuterostomes: These represent two developmental pathways; protostomes develop the mouth first, while deuterostomes develop the anus first.

  • Phyla Characteristics: Nine major animal phyla can be characterized based on their tissue structures, symmetry, embryonic layers, and evolutionary traits, providing insight into their evolutionary history.

Vocabulary

  • anterior

  • bilateral symmetry

  • Bilateria

  • blastula

  • Deuterostomia

  • dorsal

  • Ecdysozoa

  • ectoderm

  • endoderm

  • Eumetazoa

  • gastrula

  • ingestion

  • invertebrates

  • larva

  • Lophotrochozoa

  • mesoderm

  • metamorphosis

  • posterior

  • protostome

  • radial symmetry

  • ventral

  • vertebrates

Invertebrate Diversity (18.5-18.16)

  • Insect Characteristics: Insects have an exoskeleton, segmented bodies, and a high reproductive rate, making them the most diverse group of animals.

  • Metamorphosis Types: Their development can be complete (egg, larva, pupa, adult) or incomplete (egg, nymph, adult), demonstrating various life cycle strategies.

  • Valuable Resources: Invertebrates offer ecological services such as pollination, nutrient cycling, and serve as food sources for many vertebrates, highlighting their importance in ecosystems.

  • Characteristics of Major Phyla: Each phylum is characterized by specific traits contributing to their survival and adaptations, such as the presence of body cavities, segmentation, or developmental stages.

Vocabulary

  • amoebocytes

  • annelid

  • arachnids

  • arthropods

  • bivalves

  • body cavity

  • centipedes

  • cephalopods

  • chelicerates

  • choanocytes

  • circulatory system

  • closed circulatory system

  • cnidarians

  • cnidocytes

  • complete digestive tract

  • complete metamorphosis

  • Crustaceans

  • cuticle

  • dorsal, hollow nerve cord

  • echinoderms

  • endoskeleton

  • errantians

  • exoskeleton

  • flatworms

  • flukes

  • foot

  • free-living flatworms

  • gastropods

  • gastrovascular cavity

  • incomplete metamorphosis

  • lancelets

  • mantle

  • medusa

  • millipedes

  • molluscs

  • molting

  • myriapods

  • nematodes

  • notochord

  • open circulatory system

  • Pancrustacea

  • pharyngeal slits

  • polyp

  • post-anal tail

  • radula

  • sedentarians

  • segmentation

  • sessile

  • sponges

  • suspension feeders

  • tapeworms

  • tunicates

  • visceral mass

  • water vascular system

Chapter 19: The Evolution of Vertebrate Diversity

The “Charismatic” Divide

  • Charismatic vs. Non-Charismatic Species: Charismatic species often gain public interest and conservation focus due to their appeal (e.g., lions, pandas) compared to less popular species that may be equally important for ecosystem health.

Vertebrate Evolution and Diversity (19.1-19.8)

  • Shared Derived Characters: Chordates are defined by key features like a notochord, dorsal hollow nerve cord, pharyngeal slits, and post-anal tail during some stage of their lifecycle, setting them apart from other animals.

  • Transitional Species: The evolution from fishes to amphibians showcased transitional species like Tiktaalik, which display characteristics suitable for both aquatic and terrestrial environments.

  • Vertebrate Group Characteristics:

    • Hagfishes and Lampreys: Jawless fishes with distinct ecological roles.

    • Chondrichthyans (sharks, rays): Cartilaginous fish characterized by their flexible skeletons.

    • Ray-finned Fishes and Lobe-finned Fishes: Diverse groups of bony fishes with unique adaptations for survival in various habitats.

    • Amphibians: Breathe through skin; require water for reproduction, representing a key transition to land.

    • Reptiles: Adapted for terrestrial life; features like amniotic eggs allow reproduction away from water.

    • Birds: Evolved from theropod dinosaurs; characterized by feathers and beaks, adaptations for flight.

    • Mammals: Defined by mammary glands; consist of monotremes (egg-laying), marsupials (pouched), and placental mammals (develop in uterus).

Primate Diversity (19.9-19.10)

  • Distinguishing Characteristics: Primates are characterized by flexible limbs, grasping hands, and enhanced vision, enabling adaptation to diverse environments.

  • Three Main Groups: Primates are divided into prosimians (lemurs, tarsiers), monkeys (Old World and New World), and apes (gibbons, great apes), showcasing complex social structures and behaviors.

Hominin Evolution (19.11-19.17)

  • Non-Linear Evolution Evidence: Fossil records indicate a branching pattern of hominin evolution rather than a direct lineage leading to modern humans.

  • Differences between Humans and Chimpanzees: Key distinctions include bipedalism in humans and variations in brain size and structure related to complex cognition.

  • Brain Size Evolution: Over time, hominins increased in brain size, correlating with enhanced tool use and social behavior.

  • Common Ancestor Evidence: Genetic studies point to a common ancestor of modern humans that existed between 160,000 and 195,000 years ago in Africa.

  • Skin Color Adaptations: Darker skin provides UV protection in equatorial regions, while lighter skin promotes vitamin D synthesis in areas with less sunlight.

  • Discovery of New Species Increase: Factors include advancements in technology, exploration of unexplored habitats, and increased interest in paleontology, contributing to the identification of new hominin species.

Vocabulary

  • amniote

  • amniotic egg

  • amphibian

  • birds

  • chondrichthyan

  • ectothermic

  • endothermic

  • eutherian

  • hominin

  • lateral line system

  • lobe-fin

  • mammal

  • marsupial

  • monotreme

  • operculum

  • paleoanthropology

  • placenta

  • placental mammal

  • ray-finned fish

  • reptile

  • swim bladder

  • tetrapod

  • vertebra (plural, vertebrae)

  • vertebral column

  • vertebrate