Biology - SBI3U - Flashcards

Levels of organization

AM OCTOBO PCEBB

• Pre-biotic

  • Atoms

  • Molecules

• Levels of an organism

  • Organelles

  • Cells

  • Tissues

  • Organs

  • Body systems/organ systems

  • Organisms

• Beyond the individual organism

  • Population

  • Community

  • Ecosystem

  • Biome

  • Biosphere

Atoms

• Smallest unit of matter

  • Cannot broken down to anything simpler by chemical means

Molecules

• Smallest unit of most compounds

• Form by chemical bonding of atom

Organelles

• Specialized structures that perform important cellular function within cell

• Found only inside eukaryotic cell

Cells

• Smallest unit of life

• Collection of living matter

• Seperated/enclosed by barrier from surroundings

Tissues

• Group similar cells work together perform specific function

Organs

• Group tissues work together perform specific function

Body systems / organ systems

• Group organs work together perform closely related function

Organisms

• Living thing composed of cell

• Multi cellular

Species

• Group organisms so similar can breed to produce fertile offspring

Population

• Group same species live same area

Community

• Group different population live same area

Ecosystem

• Group all organism live particular place

  • Including nonliving environment

Abiotic

• Nonliving

Biotic

• Living or once living

Biome

• Group ecosystems with same climate and similar dominant communities

Biosphere

• Part Earth which life exist

  • Land

  • Water

  • Air

  • Atmosphere

Characteristics of life

CROGRED

• Composed of cells

• Reproduction

• Obtain and use energy (metabolism)

• Growth and development

• Respond to environment (homeostasis)

• Evolution and adaptation

• DNA is universal genetic code

Composed of cells - characteristics of life

• Cell basic unit of life

• All cell come from preexist cell

Unicellular

• Organism composed one single cell

Multicellular

• Organism composed many cell

• Diversity and specialization of function

Asexual reproduction

• Single parent copy DNA produce genetically identical offspring

• Can mean rapid fire reproduction of great number of identical organism

Sexual reproduction

• Two different parent cell unite produce first cell of new organism

• Offspring genetically unique

  • Lead to genetic diversity and specialization

Obtain and use energy (metabolism) - characteristics of life

• All live thing obtain energy from environment or surrounding

  • Use for (these processes occur different rate):

    • Growth

    • Development

    • Reproduction

    • Excretion

Metabolism

• Metabolism = anabolism + catabolism

• Combination of different chemical reaction that build and break down material as organism carry out life

Anabolism

• Synthesizing compounds

  • Expends energy

Catabolism

• Breaking compounds into simple components

  • Releases energy

Growth and development - characteristics of life

• Unicellular organism grow mostly simple increase in size

• Multicellular organism undergo extensive development from fertilized egg

  • Dividing many times to produce multitude of cell in mature organism

Differentiation

• Changing of shape and structure to perform different function

Respond to environment (homeostasis) - characteristics of life

• Organism detect and respond to stimulus or anything in environment that cause response

Internal stimuli

• Happens internally

  • Like blood glucose level

External stimuli

• Light

• Touch

• Sound

• Heat

• Smell

Homeostasis

• Automatic (self-controlled) processes which organism respond to stimuli so condition in body is suitable to sustain life

Evolution

• Ability of group organism change over time

  • Invaluable for survival in constant change environments

Adaptation

• Trait living thing help it compete and survive to reproduce in environment

DNA - characteristics of life

• All life based on universal genetic code

• 4 letter code

• Determines inherited traits of all organisms

• Type of biomolecule known as nucliec acid

• Three dimensional shape called double helix

  • Allow for duplication and reading of gene it encode

Cell membrane

• Boundary of cell

• Made of phospholipid bilayer

  • Phospho = phosphade head

  • Lipid = fatty acid tail

  • Bi = two layer

Nucleus

• Control center of cell

• Contain DNA

• Double membrane

• Generally one per cell

• Generally easy see under microscope

Cytoskeleton

• Provide shape and structure

• Help move organelle around cell

• Three types filament

  • Microtubules 25nm diameter

  • Actin filaments 7nm diameter

  • Intermediate filaments 10nm diameter

Endoplasmic reticulum (ER)

• Connected to nuclear membrane

• Smooth ER

  • No ribosome

  • Makes lipid

• Rough ER

  • MRNA to ribosome

  • Make protein

Ribosome

• Site protein synthesis

• Attached rough ER or float free in cytoplasm

• Produced in nucleolus

• Polypeptide = chain amino acid

Golgi apparatus

• Store, modify, package protein

• Molecule transport to and from through vesicles

Lysosome

• Type of vesicle only in animal cell

• Contain digestive enzyme that break down waste

Mitochondria

• Cellular respiration

  • To release energy for cell to use

• Double membrane

• Has own DNA

Chloroplast

• Contain green pigment chlorophyll

• Site food (glucose) production

• Double membrane

• Has own DNA

• Absorb light

  • Catalyst for photosynthesis

• Plants

Cell wall

• Rigid protective barrier

• Outside cell membrane

• Made of cellulose (fiber)

• Bacteria and plants

Vacuole

• Storage for

  • Water

  • Food

  • Enzyme

  • Waste

  • Pigment

• Large central in plant cell

• Many smaller in animal cell

Centriole

• Aid in cell division

• Usually only animal cell

• Made of microtubules

Why classification

• Organize all discovered organism

• Give organism standard name

• Scientist in different place can talk without confusion

Robert Whittakers 1969

• Five kingdom system

  • Monera

  • Protista

  • Plantae

  • Fungi

  • Animalia

Carl Woese 1970 and 1990

• Six kingdom system

  • Eubacteria

  • Archaebacteria

  • Protista

  • Plantae

  • Fungi

  • Animalia

• Three domain system (eubacteria and archaebacteria seperated because more closely related eukaryote than each other)

  • Eubacteria

  • Archaebacteria

  • Eukarya

Thomas Cavalier-Smith 1987

• Eight kingdom system (protista defined by what they are not, split protista)

  • Eubacteria

  • Archaebacteria

  • Archezoa (fungi like)

  • Chromista (plant like)

  • Protista (animal like)

  • Plantae

  • Fungi

  • Animalia

Carolus Linnaseus

• Swedish botanist

• Developed classification system based on simlarity between organism

Factor of classifying kingdom

• Cell type

  • Prokaryote vs eukaryote

• Cell number

  • Unicellular vs multicellular

• Feeding type

  • Autotroph/producer vs heterotroph/consumer

• Reproduction

  • Asexual vs sexual

Taxonomy

• Science of naming organism

Taxonomist

• Person study taxonomy

Taxon

• Level use for classification

• Increasingly specific

  • Domain

  • Kingdom

  • Phylum

  • Class

  • Order

  • Family

  • Genus

  • Species

Binomial nomenclature

• Genus + species

• Name have latin origin

• Globally recognized

• Name first letter uppercase

• Written underlined each word separately or italics

• Genus more closly related then species

  • Species usually characteristic

Dichotomous key

• Two part questions to identify related individual

• No objective criteria, no comparison

Identifying species concept

• Morphological species concept

• Biological species concept

• Phylogenetic species concept

Morphological species concept

• Focus on morphology of organism

• Advantage

  • Simple use

  • Most widely used

• Disadvantage

  • Too much variation within species

    • Dolphins vs sharks

Morphology

• Body size, shape, and other structural features

Biological species concept

• Simple characteristics and ability organism to interbreed and produce fertile offspring

• Advantage

  • Widely used scientist

• Disadvantage

  • Cannot apply

    • Species reproduce asexually

    • Uncertain for population physically separate

    • Fossil species which no longer reproduce

Phylogenetic species concept

• Focus on evolutionary relationship among organism

• Advantage

  • Can apply extinct species

  • Consider information about relationship among organism learned from DNA analysis

• Disadvantage

  • Evolutionary history not known for all specie

Phylogeny

• Study of evolutionary relationship and shared ancestry

• Determined by (DMS)

  • Development traits (embryology)

  • Molecular traits (homology)

  • Structural traits (genetics and molecular biology)

Evolution

• Scientific theory that describe change in specie over time and their shared ancestry

Phylogentic tree

• Branching diagram to show evolutionary relationship

• Tip represent particular species/group species

• Moves back through time (lower = older)

• Meeting place of branch is common ancestor

Clade

• Taxonomic group that include single common ancestry and all its descendants

First living thing

• Archaebacteria likely first living thing

  • Likely anaerobic and chemotrophic

Cyanobacteria

• Among earliest known life form in fossil record

  • Appear 3.5-2.5 billion year ago

• Evidence by stromatolites

  • Layers rock formed by growth microbial mats

• How know (GAP)

  • Genomic data

    • Low level physiological complexity

  • Ancient metabolic processes

    • Presence ancient metabolic process such as methanogenesis

  • Phylogenetic placement

    • Placement in phylogenetic tree

Prokaryote

• No membrane bound organelles

• Every imaginable habitat

• Smallest organisms on Earth

• Not very diverse

  • Difference is biochemistry and DNA

• 1% of total species

• Mostly unicellular

• Two groups

  • Archaebacteria

  • Eubacteria

Prokaryote importance

• Most nonpathogenic

• Mutualism = important residence in intestinal track animal

• Important role ecosystem as decomposer and producer

• Convert atmospheric nitrogen to usable form for plant

• Help produce bread, cheese, yogurt, beer, antibiotic

Archae

• Prokaryote

• Cell wall no peptidoglycan

• Inhabit extreme environement

• No pathogenic archaea

• Reproduction

  • Binary fission

Archaea more closely related eukaryote than bacteria

• Genetic similarities

  • Genes and metabolic pathways involved in essential processes like transcription and translation

• Phylogenetic studies

  • Molecular data shows genetic makeup of archaea places them closer to eukaryote

• Early life

  • Lineage show eukaryotes emerged from archaea

• Lokiarchaeota

  • Closest known archael relatives to eukaryotes

Types of archaea

• Methanogens

• Halophiles

• Thermophiles

• Psychrophiles

Methanogens

• Convert hydrogen and carbon dioxide into methane for energy

• Oligate anaerobe

• Digest cellulose in cow and termite gut

• Also swamp, wetland, garbage dump

Halophiles

• Salt loving

• Grow very salty condition, Dead Sea, food preserved by salting

• Mostly aerobic

Thermophiles

• Heat loving

• Live very high temperatures, ocean hydrothermal vent, hot spring in Yellowstone National Park

• Use sulfer or sulferic acid generate energy

• Live very low pH

Psychrophiles

• Cold loving

• Found mostly Antarctic and Arctic ocean

• Optimal temperatature rance -10C to -20C

Eubacteria

• Move using flagella

• Have pili

  • Stiff protein that help cell attach one another

• Peptidoglycan in cell wall

• May have outer capsule

  • Provide protection

  • Reduce water lost

  • Resist high temperature

  • Resist antibiotic and virus

• Reproduction

  • Binary fission

  • Conjugation

Eubacteria structure

• Flagellum

• Pilus

• Capsul

• Cell wall

• Plasma membrane

• Cytoplasm

• Nucleoid (DNA)

• Ribosomes

Shapes of bacteria

• Cocci (spherical)

• Bacilli (rod)

• Spirillus (spiral)

• Aggregation of shapes

  • Single, diplo, strepto (chains), staphlo (clusters)

Autotroph

• Make own food

Heterotroph

• Use compound from other

Phototroph

• Energy from sunlight

Chemotroph

• Energy from chemical

Obligate aerobe

• Need oxygen to survive

Obligate anaerobe

• Killed by oxygen

Facultative anaerobe

• Use oxygen when present but live anaerobically when oxygen absent

Binary fission

• Asexual

• DNA replicated, parent cell split into two identical daughter cell

• Quick replication

  • Increase number but more error

• Process

  • Cell replicate DNA

  • Cytoplasmic membrane elongate seperate DNA molecule

  • Criss wall form, membrane invaginate

  • Cross wall from completly

  • Two identical daughter cell

Conjugation

• Sexual

• Bacterial cell pass copy of plasmid to nearby bacterial cell through hollow pilus

• DNA exchange different species = horizontal gene transfer

• Process

  • Donor cell attach to recipient cell with pilus

  • Pilus draws cell together

  • Cell contact one another

  • One strang plasmid DNA transfer to recipient

  • Recipient synthesize complementary strand

  • Donor synthesize complentary strand restore to complete plasmid

Endospore

• Bacteria form endospore around chromosome when under stress

• Metabolically inactive, highly resistant harsh condition long time

Gram positive bacteria

• Purple stained

• Thick cell wall

• Absorb stain

• Lots of peptidoglycan

• Exotoxin, protein produce inside pathogenic bacteria released during lysis

Gram negative bacteria

• Pink stained

• Thin cell wall

• Small layer peptidoglycan

• Toxic and usually bad bacteria

• Harder to kill

• Endotoxin, in outer layer of gram negative liberated when bacteria die

Antibiotics

• Combat bacteria by interfering with peptidoglycan in cell wall

  • Staining to determine what antibiotic needed

    • Gram negative bacteria small layer peptidoglycan so need DNA and thin cell wall targeting antibiotic

Antibiotic resistance

• Antibiotic target most susceptible bacteria first

  • Should always finish full course antibiotic prescription

• If resistant bacteria remain and reproduce will create line of immune bacteria

Eukaryote

• Membrane bound organelles

• Unicellular or multicellular

• Four groups

  • Fungi

  • Protista

  • Animalia

  • Plantae

Fungi

• Eukaryotic

• Stationary

• Heterotroph

• Cell wall made of chitin

• Most multicellular

  • Except yeast

• More closely related animalia then plantae

• Reproduction

  • Anastomosis

  • Spores

  • Budding

  • Fragmentation

Fungi structure

• Fruiting body (reproductive structure)

  • Cap

  • Gills

  • Ring/skirt

  • Stipe/stem

  • Volva

  • Spores

• Mycelium (make up body)

  • Hyphae/mycelial threads

Fungi nutrition

• Saprotroph (saprobe)

• Parasitic

• Symbiotic (mutualist)