Bio 158 Exam 1

Bio 158 Form and Function Exam Lectures 1-5

Levels of Organization

Atom —> molecule —> cell —> organ —> organism —> population —> community —> ecosystem —> biosphere

What is an organism? Must have 7 characteristics

1) Cellular organization

2) Ordered complexity

3) Response to stimuli

4) Growth, development, reproduction

5) Energy utilization

6) Homeostasis

7) Evolutionary adaptation

Cellular organization

• Basic membrane-bound unit of life

Ordered complexity

• Complexity: Many different components that interact

• Order: according to a pattern

Response to stimuli

• React to changes in environment

Growth, Development, Reproduction

• Organisms can create more organisms of the same species

Energy utilization

• take in energy and use it to perform work
  

Homeostasis

• Maintain a stable internal environment that differs from the external environment

Evolutionary adaptation

Mutation + natural selection produces changes over generations

The 3 domains of life

• bacteria

• archaea

• eukaryotes

Cellular structure of bacteria and archaea

• single celled prokaryotes

Prokaryotic Cells

Simple organization:

• Cytoplasm surrounded by a plasma membrane, encased in a cell wall

• Lack membrane-bound organelles

• Some move using flagellum/cilia (not unique to prokaryotes)

Plasma membrane carries out some functions in some prokaryotes
Example: Cyanobacteria

First to evolve

Eukaryotic Cells

• Different organelles for different functions

• Nucleus: contains majority of DNA

• Many other organelles involved in protein synthesis

Cellular structure of different Eukaryas

• Plantae: Cell walls made of cellulose and obtain energy from photosynthesis

• Fungi: Cell walls made of chitin and obtain energy by absorbing digested material

• Animalia: No cell walls, obtain energy by ingesting and then digesting internally

• Protista: all unicellular eukaryotes except for yeast, and multicellular algae

Eukaryotic Cells: Plant vs. Animal

Plant

• chloroplast

• cell wall

• vaucole

Animal

• lack of chloroplast

• lack of cell wall

• lack of vaucoles

Both

• eukaryote (membrane-bound organelles)

• similar membranes

• mitchondria

Prokaryote: Structure different Shapes

• Bacillus

  • has more surface area per unit of volume

  • tube like

  • do better in more resource-poor environments

  • often solitary + move with flagella

• Coccus

  • balloon shape

• Spirillum

  • spiral

Prokaryote: Nutritional Strategy

Many strategies, including:

• Autotrophs = make own nutritional molecules

  • Chemosynthesis = use energy from chemical reactions (e.g., using H2S)

  • Photosynthesis = use energy from sunlight

• Heterotrophs = consume nutrients

  • Endocytosis = cell engulfs nutrients

Prokaryotes: Reproduction

• Reproduce asexually with binary fission

• Are able to exchange genetic information with conjugation

Prokaryotes: Diversity

• Estimated over 99% of prokaryotes have yet to be discovered

• so many

Prokaryotes example: Nitrogen-fixing bacteria

• Convert Nitrogen in the air to forms of Nitrogen plants can use

• Found in both water and the soil

Prokaryotes example: Bioremediation

• Bacteria break down organic matter + toxins (e.g., oil spills, microplastic pollution)

Prokaryotes example: Human Disease

• Bacteria Borrelia burgdorferi

• Transmitted via tick vector

Protist

• Eukaryotes that aren’t plants, fungi, or animals

Origin of the nucleus

• Cell wall had to be lost 1st

• The nuclear membrane is an extension of the ER network

• The nuclear membrane protects and isolates the nucleus

• Thought to have evolved from infolding of plasma membrane

Endosymbiosis Theory

• Ancestors were prokaryotes that lived symbiotically

• Energy-producing (aerobic) bacteria lived inside of larger bacteria

• These aerobic bacteria became modern-day mitochondria

• Photosynthetic bacteria lived inside of larger bacteria

• These photosynthetic bacteria became modern-day chloroplasts

Evidence for Endosymbiosis

• Mitochondria and Chloroplasts have their own DNA: Where from?

  • Turns out to be very similar to DNA in bacteria

• Many antibiotics that inhibit protein synthesis in bacteria also inhibit protein synthesis in mitochondria and chloroplasts

• Chloroplasts and mitochondria reproduce in the same way as bacteria

Protist: Structure

• Eukaryotic Cells

• All eukaryotes that aren’t plants, animals or fungi are lumped into protists

• No distinct cell type (some plant-like, some animal-like)

• Micro and macroscopic

Protist: Nutritional Strategy

• Wide range of nutritional strategies

  • Some photosynthesize

  • Some consume other organisms

  • Some can do both!

• Some help decompose materials

Protist: Reproduction

• Depending on the species, can reproduce:

  • asexually (binary fission)

  • sexually (conjugation)

• Some species can do both

Protist example: Malaria parasite

• Plasmodium

• Complex life cycle

• Blood stage causes symptoms

Protist example: Kelp

• Are not plants—actually algae

• Look like complex plants

• Have specialized regions

• Unlike plants, have no vascular tissue

Protist example: Slime molds

• Can be:

  • many individual cells that sometimes cooperate in order to reproduce

  • one huge cell with many nuclei

• Studied to understand evolution of multicellularity (transitional form)

Fungi

• eukaryotes

• in monophylectic group

Fungi: Structure

• Can be single-celled or multicellular form with different cell types. If multicellular, body = mass of connected hyphae

• Hyphae can be one continuous or branching tube with many nuclei, or chains of cells with pores.

• Cytoplasm flows freely throughout hyphae, which allows hyphae to grow rapidly

• Mass of connected hyphae: mycelium, can be up to many meters long!

• Cell walls made of chitin, a polysaccharide

Fungi: Nutritional strategy

• are heterotrophs that release digestive enzymes + absorb nutrients

• Have a large surface-to-volume ratio

• Break down cellulose and lignin in wood

• Some are even carnivorous

Fungi: Reproduction

• Can have sexual or asexual reproduction

• Produce spores

Fungi ecological roles

• Found in nearly every environment

• Important decomposers

• Important for plant nutrient uptake

• Live in symbiosis with many other organisms

• Important for many foods

Fungal example: mushrooms

• Most familiar fungi

• Mushrooms, toadstools, rust infections

• Reproduce sexually with basidia

• Gills produce millions of spores

Fungal example: “Humongous Fungus”

• The largest known organism on earth is a species of honey
  mushroom (Armillaria ostoyae) living in Oregon

• Mycelium covers 3.5 square miles and is estimated to weigh up to 25,000 tons

• A smaller one in northern Michigan covers over 91 acres

Fungal example: yeast

• Can be pathogenic

• Can be used for fermentation: Bread, Beer, etc.

Plants: Structure

• Multicellular

• Plant cell:

  • Eukaryotic

  • Chloroplasts

  • Vacuoles

  • Cell walls made of cellulose

Plants: Nutritional Strategy

• Almost all plants use photosynthesis to generate
  food

• Plants all require nutrients from the medium (typically soil) in
  which they grow

• Nitrogen, Phosphorus, and Potassium are the most common

Plants: Reproduction

• Plants have both haploid and diploid phases of the life cycle (haplodiplontic)

• Can reproduce asexually: spores, vegetative propagation

• Can also reproduce sexually with male and female gametes

Plants: Roles

• Primary producers

• Generate oxygen and store carbon

• Prevent erosion + provide shelter

• Provide many products:

  • Textiles, drugs, dyes, building materials, fuel, etc.

What have plants evolved from?

• green algae

Challenges for plants to living on land

• drying out

• exposed to UV radiation

• different temperature shifts

Adaptations to terrestrial life: Vegetative

• Waxy cuticle: to prevent desiccation

• Stomata: small openings that allow gas in and out

• Some plants have specialized tissues for transport

  • Xylem: water + minerals

  • Phloem: sugars

Adaptations to terrestrial life: Seeds

• Two main groups:

  • Seedless plants: mosses, ferns, etc.

  • Seed plants: forbs, trees, grasses, etc.

Adaptations to terrestrial life: Function of Seeds

• Protects the embryo

• Provides nutrition for the embryo

• Provides a dormant phase to allow the embryo to survive until good environmental conditions

Seed plants: Gymnosperms

• “Naked seed”

• No fruits or flowers

• Example: pine tree

Seed plants: Angiosperms

• ”Seeds in vessels”

• Fruits & flowers

• Have a unique double fertilization

Flower structure

• Modified stems/leaves
• Embryo within ovary

Pollination syndrome

• Pollination syndrome = sets of traits that have evolved to for different pollen vectors

• How are wind-pollinated flowers different from animal-pollinated flowers?

Flower: Form and Function

• What aspects of these flowers are different?

  • Color

  • Shape (petals, stamens, carpels)

  • Odor

  • Reward (nectaries)

Fruit: Form and Function

• What is the function of a fruit?

  • Protect seeds

  • Help them spread

  • Fleshy fruits do this by getting animals to collect/eat them

Fruit: Form + Function- Dispersal

• ants

• other

• other

Pollen: Form and Function

• Escape pods

  • they protect and provision

• Pollen grains

  • protect from bacteria, drying out, and UV radiation

Characteristics of Animals

All animals

Structure:

• multicellular

• lack cell walls

Nutritional strategy:

• heterotrophic (ingest nutrients)

Most animals

Reproduction: sexual

Other traits:

• active movement

• unique tissues

Animal Body Plans: Evolution 5 Key Innovations:

1) Symmetry

2) Specialized tissues

3) Body cavity

4) Patterns of Embryonic Development

5) Segmentation

Symmetry: Asymmetric

• no lines because no equal on one side

Symmetry: Radial Symmetry

lots of different lines splitting and all would be the same on each side

Symmetry: Bilateral Symmetry

• 2 sided symmetry

• one line - humans but not all the same

Bilateral symmetry has this. What is it?

• cephalization

  • concentration of nervous tissue at anterior end

Specialized tissues

All animals except sponges

4 main types:

• Epithelial: forms the outer layer of the body and lines the inner cavities

• Connective: support and protection of organs and limbs

• Muscular: aids in movement

• Nervous: carry electrical signals from the brain throughout the body and back

Body cavity: Germ layers

During embryonic development, cells of most animals organize into 3 layers:

• outer ectoderm

• intermediate mesoderm

• inner endoderm

Give rise to different parts of the body depending on the organismal group

Body Cavity: Acoelomate

• no body cavity between the digestive tract and the muscle layer

Body Cavity: Pseudocoelomate

• have a body cavity between tissues partially lined with mesoderm

• organs held loosely

Body Cavity: Coelomate

• have a body cavity with a complete mesoderm lining

• organs are attached, but can still move somewhat

Allows:

• more complex organ systems

• distribution of materials

Patterns of embryonic development

Protostomes:

• first opening in development becomes mouth

• determinate development

Deuterostomes:

• first opening becomes anus

• indeterminate development

Segmentation

Repeated units clear during early development (may fuse or differentiate later)

Benefits:

• Damage to one segment may not be fatal to organism

• Locomotion is more effective because individual segments can move semi-independently

Who is Asymmetric

• Porifera (sponges)

Who has Bilateral symmetry

• Platyhelminthes (flatworms)

• Annelida (segmented worms)

• Mollusca (snails, clams, squid, etc)

• Nematoda (round worms)

• Arthropoda (insects, crustaceans, etc)

• Echinodermata (starfish, sea urchin etc),

• Chordata (vertebrates)

Who has Radial symmetry

• Cnidaria (jellies)

• Echinodermata (starfish and sea urchin) and Chordata (vertebrates) as adults

Who has specialized tissues

• All expect Porifera

Who does not body cavity

• Porifera (sponges)

  • no germ layers

• Cnidaria (jellies)

  • has 2 germ layers

Who has the body cavity Acoelomate?

• Platyhelminthes (flatworms)

Who has the body cavity Pseudocoelomate?

• Nematoda (round worms)

Who has the body cavity Coelomate?

• Annelida (segmented worms)

• Mollusca (snails, clams squid slug etc)

• Arthropoda (insects crustaceans etc)

• Echinodermata (starfish, sea urchin etc)

• Chordata (vertebrates

Who does not have embryonic development?

• Porifera

• Cnidaria

Who has the Embryonic development Protostome?

• Platyhelminthes (flatworms)

• Annelida (segmented worms)

• Mollusca (snails, clams, squid etc)

• Nematoda (round worms)

• Arthropoda (insects, crusteaceans etc)

Who has the Embryonic development Deuterostome?

• Echinodermata (starfish, sea urchin etc)

• Chordata

Who has segmentation?

• Annelida (segmented worms)

• Arthropoda (insects etc)

Who does not have segmentation

• Porifera (sponges)

• Cnidaria (jellies)

• Platyhelminthes (flatworms)

• Mollusca (snails, clams etc)

• Nematoda (round worms)

• Echinodermata (starfish, sea urchins)

• chordata (vertebrates)

Other information on Phylum (first half of it)

Porifera

• Several cell types

• Reproduce sexually and asexually

Cnidaria

• Have stinging cells for capturing prey (nematocysts)

• Also includes anemones and corals

Platyhelminthes (Flatworms)

• Some are studied for regeneration properties

Nematoda (Roundworms)

• Some are microscopic

• Have adapted to almost every environment

The other half of other info on phylum

Mollusca (Snails, Clams, Squid, etc.)

• Have a protective body covering and often a shell

Annelida (Segmented worms)

• Earthworms play key role in soil habitat

Arthropoda (Insects, Crustaceans, Arachnids, etc.)

• Jointed appendages

• Exoskeleton made of chitin

Echinodermata (Starfish, Sea Urchins, etc.)

• Have an endoskeleton of calcium carbonate plates

• Also studied for regenerative properties

Chordates

• MOST Have an endoskeleton made of bone or cartilage

3 subphyla:

• Cephalochordata

• Urochordata

• Vertebrata

Characteristics of all chordates (at some part of development):

1. Hollow dorsal nerve cord

2. Notochord

3. Pharyngeal slits: filter feeding organ

4. Post-anal tail

Non-vertebrate chordates

• Do not form vertebrae or other bones

• Look very different from vertebrates

• Cephalochordata and Urochordata

Lancelets: Cephalochordata

• Resemble a lancet (surgical blade)

• 23 species

• Found in shallow marine habitats

Tunicates and Salps: Urochordata

• About 1250 species

• Immobile as adults

• No major body cavity or segmentation as adults

• Larvae stage exhibits all characteristics of chordates

Vertebrates: 5 Key characteristics

1) Vertebral column

2) Head

3) Neural crest: cells during development that migrate to form different structures

4) Internal organs

5) Endoskeleton

7 Classes of Vertebrates

Domain: Eukarya

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class:

• Agnatha: Jawless fish

• Chondrichthyes: Cartilaginous fish

• Osteichthyes: Bony fish

• Amphibia: Amphibians

• Reptilia: Reptiles

• Aves: Birds

• Mammalia: Mammals

Agnatha

• Jawless fishes

• Lampreys and Hagfish

• Hagfish secrete a slime to avoid predation

Chondrichthyes

Cartilaginous fishes

• Include sharks, skates, and rays

• Have electroreceptors

• Have scales that are modified teeth

has jaws

Osteichthyes

• Bony fishes

• Most have a swim bladder

• Highly mobile fins

• Most fertilization external

has bones

Amphibia

• Include frogs, toads, salamanders, and caecilians

• First vertebrates to walk on land

• Have a partially divided heart

• Supplement lungs by breathing through skin

has 4 legs, lungs, and amniotic eggs

Reptilia

• Include lizards, snakes, turtles, crocodiles, and dinosaurs

• Have amniotic eggs

• Dry skin

has lungs and anmiotic eggs

Aves

• Birds

• Feathers

• Lightweight skeleton

• Highly efficient respiration and circulation

• Endothermic

has lungs and amniotic eggs

Mammalia

Traits:

• Hair

• Mammary Glands

• Endothermy

• Placenta (most species)

has bones, legs, amniotic eggs, hair and endothermic

Three groups of mammals

Monotremes

• egg-laying mammals: echidna and platypus

Marsupials

• pouched mammals: kangaroos, opossum, etc.

Placentals

• embryo in uterus: everything else

Plant Structure: One of the systems

Shoot system: stems and leaves.

• Allows: Photosynthesis, reproduction