Patterns
Patterns
(adapted from Hoagland and Dodson)
Life builds from the bottom up
Influence of small things
Large things are made of smaller things
Smaller things are made of even smaller things
Organisms->organ systems->organs->tissues->cells->organelles->etc.
Life assembles itself into chains
Information chains: store and transmit information
Working chains: proteins, carbohydrates
Life needs an outside and an inside
Interacting items (stuff) must be kept together so they can interact efficiently and be
protected
Chemicals in a cell
Emperor penguins
Bark on tree
Atmosphere
Life uses a few themes to generate many variations
300,000 types of beetles
28,000 species of fish
Monocots-parts in threes
Dicots-parts in fours and fives
Life organizes with information
Information codes for the parts that make the whole work
Lump and Split
Categorize to make things simple
Split along similarities
Most basic: cellular architecture
Prokaryotes: simple, no compartments
Eukaryotic: more complex, have compartments surrounded by membranes
Three Domains
Bacteria
Archaea
Eukarya
Bacteria, Archaea
Microscopic
Single-celled (may live in films)
Both are prokaryotic
Both play important roles in ecosystems
Simple reproduction
Found everywhere
Numerous
Bacteria, Archaea
Energy and matter (nutrients) obtained in many different ways
May be pathogens
Anaerobic or aerobic or both
Archaea
Major differences when compared to Bacteria:
Genes and metabolic pathways more like eukaryotic cells
Different fat in cell membrane (ether lipid)
Best known as extremophiles: halo-, thermo-, etc.
Commensalism and mutualism (methanogens)
Morning Glory Hole, Yellowstone National Park
EUKARYA
Protista
Plantae
Fungi
Animalia `
Protista
Junk drawer
Early eukaryotes
Variation in modes of nutrition and movement
First group where sex is found
Pathogens
Animal-like, plant-like, fungal-like
Protista
Harmful algal blooms (HAB): red tide
Plants
What Makes a Plant a Plant
Photosynthetic
Multicellular
Plants
Characteristics of plants
Photosynthetic
Multicellular
Sessile (fixed in one place)
Possess cell walls
Possess chloroplasts
Display ―alternation of generations‖
Most are land-dwelling
Kingdom Plantae
Adaptations to Terrestrial Existence
Cell walls of cellulose w/ lignin
Posses cuticle and stomata
Protected embryo
Oogamous (don’t need water to reproduce)
Types of Plants
Members of the plant kingdom can be separated into four main types
Bryophytes (including mosses)
Seedless vascular plants (including ferns)
Gymnosperms
Angiosperms
Bryophytes
(mosses, hornworts, liverworts)
Lack vascular system
Grow close to the ground; short
Grow in moist areas usually
Lack root system (possess rhizoids)
Have gametophyte dominant life cycle
Phylum Pterophyta
True ferns
Appearance of vascular tissue: specialized tissues that extend through plant
Carries water, nutrients
Allows plant to grow larger and taller
Seed Plants
Gymnosperms
Angiosperms
What is a seed?
Adaptation to land life
Embryo
Stored food
Resistant covering (seed coat)
Appeared 360 mya
Gymnosperms
Naked seeds
Seeds not enclosed in chamber
Seeds are exposed on modified leaves
Modified leaves form cones
Gymnosperms
Cycadophyta
Ginkgophyta
Gnetophyta
Coniferophyta
Gnetophyta
Welwitschia
50 x 500 mile strip along coast of Namib desert
Less than 1 inch rainfall
Abundant fog
Only 2 leaves
Grow entire life from the leaf base
Welwitschia
Pinophyta
―the conifers‖
Cone bearing plants
4 families
Araucariaceae
Podocarpaceae
Cupressaceae
Pinaceae
Cones of all sizes
Angiosperms
Seeds in a chamber (not naked)
250,000 species
130,000 million years
Most evolved group of vascular plants
Largest Flowering Plant:
Eucalyptus regnans: 100 meters high
Samllest Flowering Plants: Wolffia, duckweed
Flowers come in all sizes
Fruits
Formed from ovary wall
Formed from accessory structures
Seeds
Fertilized reproductive structures become:
Ovule of flower becomes a seed
Ovary becomes a fruit (most of the time)
Plants
Base of terrestrial ecosystems energy pyramid
Some flowering plants coevolved with insects
Flowering plants feed the world:
Grasses—wheat, rice, maize, barley, oats, etc
Roots or root-like structures—potatoes, yams, cassava
Fungi and Lichens
Fungi
Multicellular Eukaryotic Heterotrophs
Closely related to Animalia
Some fossils ≈ 500 MYA
Fungi: Ecological Roles
Decomposers (saprobes)
Parasites
Mutualistic symbionts (mycorrhizal)
Food source: tasty, tasty
Mushrooms
Morels
Truffles
Cheeses: bleu, gorgonzola, stilton
Fungi
Plant pathogens
Rusts
Smuts
Molds
Human pathogens
Athletes foot
Yeast infections
Dramatic infections in immune-compromised individuals
Fungi
Psychedelics
Recreational
Religious
Hyphae
Fungi Phyla
Phylum Zygomycota
(Bread Pin Molds)
Coenocytic hyphae
Asexual reproduction via sporangia
Sexual reproduction via zygosporangium
Zygomycota Life Cycle
Phylum Ascomycota
(cup fungi, molds, powdery mildews, yeast, truffles, morels)
The Ascomycetes
Ascomycota Life Cycle
Complex Ascomycetes
Simple Ascomycetes
Imperfect Fungi
Phylum Basidiomycota
(mushrooms, puffballs, shelf fungi)
Reproduction
Reproduce asexually by breaking into pieces
Reproduce sexually through soredia
Fungus also produce spores
Ecological Roles
Accelerate weathering of rocks/bark into soil by secreting lichenic acids
Strong nutrient absorbers
Sensitive to air pollution
Yield litmus
Crustose: dry crusty, often colorful
Foliose: leaf-like lobes
Fruticose: erect, miniature ―shrubs‖
Basidia: sexual sporangia that produce basidiospores
Basidiomycota Life Cycle
Animalia
What Is an Animal?
Characteristics of animals
Pass through a blastula stage during embryonic development
Hollow, fluid filled ball of cells forming shortly after fertilization
Only animals form a blastula
Multicellular
Heterotrophic
Lack cell walls
What Is an Animal?
Characteristics of animals
Pass through a blastula stage during embryonic development
Hollow, fluid filled ball of cells forming shortly after fertilization
Only animals form a blastula
Multicellular
Heterotrophic
Lack cell walls
Blastula
What Is an Animal?
Most animals are motile
Some are sessile for at least a portion of their lives
Most animals are macroscopic
Some are microscopic
Some animals possess a backbone
Most are invertebrates
We will study 9 of the 36 to 41 animal phyla
Across the Animal Kingdom:
Nine Phyla
Phylum Porifera
Sponges
Most primitive form of animal life
Most are marine
Some live in freshwater
Adult form is a sessile filter feeder
Feeds by drawing water in through pores and then filtering out nutrients
Porifera
Porifera
Phylum Cnidaria
Jellyfish, sea anemones, and their relatives
Most are marine
Some live in freshwater
Use stinging tentacles to capture prey: nematocysts
Two life stages
Free-swimming medusa
Polyp stage attached to a surface
Cnidaria
Cnidaria
Cnidaria
Phylum Platyhelminthes
Flatworms
Some are human parasites
e.g., Tapeworms, flukes, etc.
(Most are not)
Live in marine, freshwater, or moist terrestrial environments
Platyhelminthes
Phylum Nematoda
Roundworms
Found in large numbers in most habitats
e.g., Farmlands, deserts, ice caps, etc.
Possess an exoskeleton called a cuticle
Shed (molted) during their life
Many are microscopic
Some are very large
Several species cause crop damage
Nematoda
Nematoda: Loa Loa
Hard to treat if onchoceriasis exists, drug used to treat onch causes encephalitis in Loa
Loa patients
Phylum Annelida
Segmented worms
Common earthworm, leech, etc.
External segmentation sometimes visible
Internal segmentation is present
Most are marine
Many live in freshwater
Some are terrestrial
Phylum Mollusca
Contains three well-known classes
Gastropods (Snails and slugs)
Bivalves (Oysters, clams, mussels, etc.)
Cephalopods (Octopus, squid, nautilus)
Possess a layer of tissue called a mantle
Secretes material that often becomes a shell
Squid and octopus are the largest and smartest invertebrates in the world
Mollusca
Mollusca
Mollusca
Phylum Arthropoda
Enormously varied phylum
Paired, jointed appendages & exoskeleton
Three major subphyla
Uniramia
Insects, millipedes, centipedes
Crustacea
Shrimp, lobsters, crabs, barnacles
Chelicerata
Spiders, ticks, mites
Insecta
Millipedes
Crustacea
Crustacea
Crustacea
Phylum Echinodermata
Star fish, sea urchins, sea cucumbers, etc.
All live in marine environments
Most move slowly across surfaces such as rocks and algae
Some are sessile
Echinodermata
Echinodermata
Echinodermata
Echinodermata
Phylum Chordata
Possess a notochord
Most possess vertebral column
Also possess (at some time)
Dorsal nerve cord
Post-anal tail
Pharyngeal slits
Phylum Chordata
Vertebrata is a subphylum
Fish
Amphibians
Reptiles
Mammals
Birds
Only approximately 1% of animals are vertebrates
The Animal Family Tree
A tissue is a group of cells that perform a common function
e.g., Muscle tissue performs the function of contracting
Eight of the phyla studied possess tissues
Phylum Porifera lacks tissues
Within a sponge, each cell acquires its own oxygen and eliminates its own waste
No collections of cells perform common functions
The Animal Family Tree
Organisms with symmetry can be divided by imaginary planes to yield sections that
are mirror images of each other
Radial symmetry is symmetry in which body sections are distributed evenly around a
central point
Typical of cnidaria (jellyfish, etc.)
Bilateral symmetry is symmetry in which two sides are mirror images of each other
The Animal Family Tree
Most animals possess a coelom
Centrally placed fluid-filled body cavity
Allows internal organs to expand, contract, and move
e.g., Heart, stomach, uterus, etc.
Typically surrounds digestive tract
Only three of the animal phyla lack a coelom
Porifera, Cnidaria, Platyhelminthes
Evolved independently in multiple phyla
Sexual and Asexual Reproduction
Reproduction can be either sexual or asexual
Sexual reproduction results from the fusion of sperm and eggs
Asexual reproduction does not involve the fusion of sperm and eggs
Many of the more primitive animal phyla can reproduce both sexually and asexually
Organs and Circulation
Most animals have organs
Highly specialized structures that usually are formed of several kinds of tissues
Organs start with Phylum Platyhelminthes
Sponges lack tissues
Tissues in cnidarians lack the organization of organs
The flatworm Dugesia has testes, ovaries, two primitive eyes, and two collections of
nerve cells (essentially, a primitive brain)
Organs and Circulation
Dugesia (and other flatworms)
Organizationally sophisticated compared to some animals
Organizationally simple compared to others
Lacks a circulatory system
All cells must get oxygen directly from the environment – this requires a flat shape
Lack a complete digestive tract (mouth = anus)
Organs and Circulation
Humans have a closed circulatory system
Blood stays within blood vessels
There is some ―leakage‖ of the liquid portion of our blood
Snails and most other molluscs have an open circulatory system
Blood flows out of blood vessels into spaces
Surrounding tissues are bathed
Veins return blood (―hemolymph‖) to the heart and gills
Organs and Circulation
Phylum Mollusca
Snails possess an open circulatory system
Some molluscs possess a closed circulatory system
Cephalopods
Squid, octopus, etc.
Open and closed circulatory systems are both common within the animal kingdom
Skeletons and Molting
Our skeleton is interior to our muscles
Endoskeleton
Many animals have an exoskeleton
e.g., Arthropods and nematodes
External material covering the body
Provides support and protection
Skeletons and Molting
Muscles exert force against an exoskeleton
Growth is limited by the exoskeleton
Molting is the periodic shedding of the exoskeleton followed by growth of a new one
Skeletons and Molting
―Hydrostatic skeleton‖
Differs from an endoskeleton or exoskeleton
Exists in annelids, cnidarians, flatworms, and roundworms
Muscles contract to squeeze the fluid-filled coelomic space
Similar to squeezing a water balloon
Animal lengthens
Egg Fertilization and Protection
Sexual reproduction in Obelia represents the most primitive condition in animals
Eggs and sperm are broadcast into the ocean
Released into the same area at the same time
Water currents bring these gametes into contact with each other
Fertilization occurs
Egg Fertilization and Protection
As we view increasingly complex animal groupings, there are general trends
Fewer eggs
More directed means of bringing gametes together
Greater protection of the fertilized eggs
Egg Fertilization and Protection
Fertilization in Obelia is external
External fertilization is rare except in aquatic environments
e.g., Amphibians use external fertilization
Gametes released into the water together
Male grasps female during amplexus
Eggs remain in the water
Protection from desiccation
Tadpoles are initially aquatic
Egg Fertilization and Protection
Fertilization in most animals is internal
May involve copulation
Male reproductive organ releases sperm inside the female
Egg Fertilization and Protection
Fertilization in most animals is internal
Males of many species produce packets of sperm
―Spermatophores‖
Must be introduced into the female reproductive tract
Sometimes introduced by the female herself
Egg Fertilization and Protection
Many vertebrates afford protection for their fertilized eggs
e.g., Frogs release gametes together during amplexus
Females of some species secrete a mucus which is beaten into a froth
Eggs and sperm are deposited into this floating foam nest
Egg Fertilization and Protection
Amphibians must lay their eggs in water or another moist environment
Eggs susceptible to desiccation
Egg Fertilization and Protection
The amniotic egg is a key adaptation present in reptiles and their descendants
Shell and internal membranes provide protection and life support
Protection from desiccation
Facilitates exchange of O2 and CO2
etc.
Egg Fertilization and Protection
Modern reptiles generally abandon eggs after laying them
Some reptiles and descendants of reptiles do protect their eggs and their young
Mammals
Birds
Crocodilians
Dinosaurs
Egg Fertilization and Protection
Mammalian embryos are protected and nurtured within the mother’s body
―Viviparous‖
Most reptiles and all birds are ―oviparous‖
Young develop in fertilized eggs laid outside the mother’s body
Egg Fertilization and Protection
Most mammals are ―placental mammals‖
The placenta facilitates embryo development: provides nutrients and oxygen and
removes wastes
Monotremes are egg-laying mammals
Platypus and echidnas
In marsupials the young develop inside the mother only to a limited extent
e.g., Kangaroos, etc.
Placental Mammal
Monotremes:Egg-laying Mammal
Marsupial: Pouched Mammals
Egg Fertilization and Protection
Mammalian care does not stop at birth
Mammals are the supreme caregivers of the animal world
e.g., Elephants may nurture their calves for the first ten years of their lives
Some of this care comes from milk produced in mammary glands