BIO III First Exam: Supermodels and Mangrove ecology

What are Supermodel organisms

Non-human species used in experiements to help us learn more about processes, procedures, treatments, we cannot study

• easy to grow in the laboratory or greenhouse

• closely resemble other organisms genetically

• have short generation times and we understand their life cycles well

• produce large numbers of offspring

• easy to manipulate genetically

-mutants can be speciic for certain traits or diseases

-genetic maps can be built to visualize loci on chromosomes or within genome

What have we learned used model organisms

• Heredity, development, physiology, underlying cellular and molecular processes have been studied using model organisms

• Gregor Mendel, “father of genetics” is considered to be the first ro select an organism to study heredity, using the Pea Plant

D. Melanogaster, Fruit Fly

• Wild tyoe: yellow-brown, red eyes, addominal rings

• sexually dimorphic ( distinct physical or behavioral differences between males and females of the same species)

• 50- day life span egg to adult- 7 days, females lay 400 eggs

• 8 chromosomes, 60% genes conserved within humans, 75% human diseases match fly genome

N. Crassa, Sac Fungus

• George Beagle and Edward Tatum selected for genetic analysis because it was easy to grow , less complex from fruit fly, and haploid life cycle

• studied for phenomena like DNA repair, genome defense, photobiology, circadian rhythms, differentiation, and development

• X- rays cause mutations

E. coli

• Prokaryote, bacillus or rod-shaped bacterium, not affected by penicillin

• First DNA polymerase was isolated from it

• recombiant DNA activities

• grows rapidly, is easy to culture and genetically manipulate, and has simple, well-understood cellular processes that reveal fundamental biological principles.

Bacteriopages

• viruses infecting bacteria

• Phage therapy is experimental, used to teat multi-drug resistant bacteria

• Simple and genetically tractable

• Fast-replicating

• Inexpensive and ethical

• Foundational to understanding gene function and regulation

S. cerevisiae, Baker’s yeast

• simple eukaryotic fungus

• study of the cell cycle, checkpoints, genes involved in DNA synthesis, nuclear division, aging

• Simple but eukaryotic

• Fast-growing and inexpensive

• Genetically tractable

• Biologically relevant to humans

C. elegans, nematode

• contains less than 1000 cells, 302 neurons

• lineages or stages can be easily tacked

• multicellular, eukaryote, organ systems

• pseudocoelomate, round worm

• programmed cell death, insulin signaling, aging, neurobiology

• simple, transparent multicellular animal with a short life cycle, well-characterized genetics, and conserved biological pathways relevant to humans.

X. laevis , African clawed frog

• vertebrate model

• produce many, large embryo all year long

• generic similarity to humans

• used in human disease modeling

D. rerio, Zebrafish

• Vertebrate model

• forward and reverse genetic approaches

• transparent body, external embyronic development

• only geneticc accessible model for appendage and heart regeneration

M. musculus, Mouse

• Leading mammalian model

• close human relative

• similar developmental issues

• prime model for stem cell biology and gene mapping

A. thaliana , Mustard plant

• small and simple genome, short life cycle, and large number of seeds

• organ development, plant- stem cell biology, patterns, immunity, variation, gravity and light responses, phytohormones

Proteome

The complete set of proteins in an organisms, cell, tissue, orgenome can express at a given time

Ortholog

genes in different species that evolved from a common ancestral gene through speciation.

• M. musculus has the highest number of orthologs of human genes

• E. coli has the smallest number of othologs of human genes

What is ecology

the study of organisms in relationship to their environment

what are ecosystems

communities of living (biotic) and non-living ( abiotic) factors

• localized. Biomes are larger geographic regions which include many different ecosystems

• coral reefs are the most diverese aquatic ecosystems

• tropical rainforests are the most diverse terrestrial ecosystems

Estuaries in Florida

• regions of brackish water, where salty ocean waters and freshwater rivers Meer, partially enclosed

• buffering landscape to prevent erosion from waves

• tidal influences can be challenging landscapes

• slows water down, amazing nurseries for animals

• productive areas

• high tide: flooding with varying ranges of saltwater

• low tide: dry, hot, salty condition for plants and burrowing animals

• Blue carbon sinks involved in reducing global warming by storing carbon from the atmosphere in its plants and soils

Halophytes

the dominant vegetation of the saltmars. plants adapted to growing in saline conditions

• composed of salt marsh grasses

• salt tolerant shrubs

• salt tolerant succulent plants

• no mature trees except at ecotones

-dynamic transiton zone or boundary between two distinct ecological communities

Zonation

• the spatial arrangement of distinct biological communities or species into bands or zones acrosss a landscape, driven by environmental gradients like altitude, latitude, or tidal depth.

• plants grow in zones based on how much physical stress they can take

Planr modiifcations to resist evaporation, and edure flooding, and saltwater intrusion

• narrow like sheath like leave to protect stomata

• aerenchyma tissue to store air or water

• special membranes and salt glands to extrude salt

• sequester salt then drop saturated leaves

Animals of the salt marsh are consumers

• estuaries are nurseries for juveniles

• protected, hard to access

• many invertebrates: crabs, mussels, oysters, insects, polychaete worms

• vertebrates: fish, birds, turtles, raccoons, crocodiles, sharks, manatees, dolphins

Flow of energy in estuaries

• sun → producers

• primary consumers

• secondary consumers

• tertiary consumers

Trophic levels

The distict hierarchial feeding position organisms occupy within a food chain or ecological pyramid classified by their primary energy source

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• decrease in biomass

• 10% energy transfer of energy between trophic level

• food chains are rarely more than 4 or 5 levels

• never experience inverted pyramids of energy

Productivity

A measure of the amount at which plants are able to create new organic matter and biomass as they grow.

• Rate of production (g/m²/ day)

• measured by amount of carbon dioxide produced and biomass

• total amount of organic material fixed or stored by organisms in the ecosystem

• primary productivity - autotrophs (NPP and GPP)

-Net Primary Productivity = Gross Primary Productivity - Respiation

• secondary productivity- consumers

-what consumers are able to use from the plants

Primary Productivity vs Secondary productivity

Primary Productivity

• Rate at which producers (autotrophs) make organic matter

• Converts sunlight (or chemical energy) into biomass

• Performed by:

  • Plants

  • Algae

  • Phytoplankton

  • Cyanobacteria

• Forms the base of the food web

• Includes:

  • Gross Primary Productivity (GPP): total energy captured

  • Net Primary Productivity (NPP): energy left after respiration

    • NPP = GPP − respiration

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Secondary Productivity

• Rate at which consumers convert food into biomass

• Uses energy already stored in organic matter

• Performed by:

  • Herbivores

  • Carnivores

  • Omnivores

• Occurs at higher trophic levels

• Depends entirely on primary productivity

Mangrove ecosystems are found in coastal intertidal zones

Coastal intertidal zones occur where land and ocean meet

In florida, four species grow in specific zones

• red mangrove - effected by daily high and low tide ( farther down)

• black mangrove- effected by daily high tide

• white mangrove- slighly effected by daily high tide

• buttonwood mangrove- not effected by tides ( farther up)

• Restricted by freezing temperatures ( freezing temps kill them)

• distributed by hurricanes

• encroachment or expansion is occurring

Magrove unique characteristics

• exposed roots

• angiosperms

• thick waxy leaves

• red mangrove propagules are viviparous (of a plant) reproducing from buds that form plantlets while still attached to the parent plant, or from seeds that germinate within the fruit.

-advantages: tougher that normal embryo and are ready to go immediately ( dont go through a period of dormancy)

-disadvantages: a lot need to be produced because its not a gurantee for success

• prop roots ( red) form dense tangles

• Pneumatophores ( black) are breathing roots in anoxic muddy soils- roots that extend up

• salt gland on leaves ( white)

Typical Mangrove Distribution

• ~30 degrees N - 30 degrees south latitude

• seem to be traveling north and south as we get fewer freezes that kill them off.