diversity test

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles

Eukaryote

A cell that contains a nucleus and membrane bound organelles

3 levels of biodiversity

genetic, species, ecosystem

genetic diversity

the variety of genes within a given species

species diversity

Number of different species in the biosphere

ecosystems diversity

range of habitats and organisms and the connections between them

Taxonomy levels

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

6 kingdoms of living things

Archaebacteria, Eubacteria, Protists, Fungi, Animals, Plants

Heterotrophic

Organisms that obtain their nutrients or food from consuming other organisms.

Autotrophic

Organisms that make their own food

Unicellular

A single celled organism

Multicellular

Made up of more than one cell.

asexual reproduction

Process by which a single parent reproduces by itself

sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

Domains of Life

Bacteria, Archaea, Eukarya

Phylogeny

Evolutionary history of a species

phylogenetic tree

A family tree that shows the evolutionary relationships thought to exist among groups of organisms

Nodes

represent common ancestors

tips

represent species

Genetic Similarities

Organisms more likely share common ancestors if they are genetically similar

Developmental Similarities

Compares early stages of embryonic development to reveal similarities

Structural Similarities

Similar anatomical structures can indicate a common ancestor

homologous structures

structures are similar in form but have different functions

analogous structures

structure AND function are similar in different organisms

Archae & Eubacteria Similarities

- Both prokaryotic - Just have a cell membrane and cytoplasm (DNA and ribosomes are just free floating in the cytoplasm)

- They also both have just one Kingdom each.

Archaea & Eubacteria Differences

- Archaea live in extreme environments, eubacteria do not.

- Archaea are ancient

- Certain Eubacteria can make us sick by infecting us.

- None of the Archaea can infect us.

The Prokaryotes:

Bacteria and Archaea

Characteristics of bacteria:

• All are single-celled.

• All are prokaryotes - DNA is not surrounded by a membrane.

• Cell organelles are NOT surrounded by a membrane.

• DNA of bacteria is made up of a single chromosome.

• All bacteria reproduce asexually by binary fission.

structure of bacteria

• Cell wall

• Cell membrane

• Cytoplasm contains ribosomes and DNA (single chromosome)

• DNA forms a ring

• May contain a plasmid (small loop of DNA)

• Some have a flagella

Bacteria shape: cocci

sphere shaped

Bacteria Shape: Bacillus

rod shaped

Bacteria Shape: Spirillum

spiral shaped

Gram stain

Bacteria can be classified by their reaction to a gram stain (made of crystal violet and iodine)

gram positive

stains purple

gram negative

pink (does not retain dye)

Photoautotrophs

energy source: light

carbon source: CO2

Chemoautotrophs

energy source: inorganic chemicals

carbon source: CO2

Photoheterotrophs

energy source: light

carbon source: organic compounds

Chemoheterotrophs

energy source: organic compounds

carbon source: organic compounds

Aerobes

oxygen is used for cellular respiration

obligate aerobes

require O2 for cellular respiration

Anaerobes

do not require oxygen

obligate anaerobes

organisms that cannot live where molecular oxygen is present

faculative anaerobes

can live with or without oxygen

Reproduction of bacteria

binary fission

Conjugation

two bacteria cells connect via a protein bridge. The plasmid of one cell is given to the other. The receiving bacteria now has a new genetic makeup. This increases its chances of surviving the new (poor) conditions.

Endospores are

In extremely poor conditions, some gram-positive bacteria form spores.

Archaebacteria

• oldest group of organisms

• live in extremely diverse environments

• Cell wall and membrane are different from eubacteria, and more than half of the genes are different as well

Eubacteria

• Most prokaryotes on Earth

• Consist of 6 groups

  1. Proteobacteria

  2. Green bacteria

  3. Cyanobacteria

  4. Gram negative - disease causing

  5. Spirochetes

  6. Chlammydias

Helpful uses of bacteria

1. Waste Management

2. Nature decomposers

3. Sewage treatment

4. Our digestion

5. Pest control

What are viruses?

acellular, non-living particles

Capsid

Outer protein coat of a virus

Virus Classification

• Morphology (shape)

• Nucleic acid type (DNA or RNA)

• Method of replication (eg. lytic vs lysogenic)

• Host organism

• Type of disease caused (eg. influenza virus, HIV)

helical viruses

having the shape or form of a helix; spiral

Polyhedral viruses

many sided viruses

spherical viruses

sphere shaped

complex viruses

complicated structures

lytic cycle

1. Attaches itself to the cell wall. Proteins in viral tail fit cell wall.

2. Virus tail releases an enzyme that dissolves the cell wall

3. Virus injects its DNA into the cell.

4. Viral DNA takes over cell's activity and host DNA is destroyed.

5. Viral DNA instructs cell to make copies of viral DNA and capsids (new viruses)

6. Viruses produce enzyme that breaks down cell wall and releases new viruses (cell lysis).

7. These new viruses attack more cells

lysogenic cycle

1. Viral DNA combines with host DNA and when host DNA is copied so is viral DNA - called lysogeny (viral DNA is inactive)

2. At some point (environmental stimulus) the viral DNA is activated, and then the viral DNA instructs the host cell to make new viruses (lytic cycle)

RNA viruses

• more severe

• have more mutations

• cannot go thru lysogenic cycle since it’s RNA

Retroviruses

• RNA virus that can turn itself into DNA and send it into the host cell

spread of viruses

insects, animals, water and global factors

Vector

an organism, typically a biting insect or tick, that transmits a disease or parasite from one animal or plant to another.

can viruses be helpful?

Yes, with gene therapy, scientists have used viruses to deliver drugs or genes to targeted cells. This could include the introduction of a normal gene into an individual's genome in order to repair a mutation that causes a genetic disorder

traits of protists:

• All are eukaryotes

• Live in moist surroundings

• Either unicellular or multicellular

• Autotrophs and/or heterotrophs

• Most reproduce asexually, although some reproduce sexually

structure of protists:

• Have their DNA in a nucleus that has a membrane

• Organelles are surrounded by membranes

• Cell metabolism carried out in organelles

• 10 times larger than prokaryotes

• Have many chromosomes in strands, thus more genes → more complex

3 categories of protists:

1. Animal-like Protists

2. Plant-like protists

3. Fungi-like Protists

Animal-like Protists (Protozoans)

• Eat or ingest material from surroundings (heterotrophs)

• Categorized into 4 subgroups, based on movement:

  1. Those with flagella

  2. Those with cilia

  3. Those with pseudopods

  4. “Others”

Zooflagellates

• Possess one or more flagella used for movement

• Eg. Parasite Trypanosoma gambiensis causes sleeping sickness

Amoebas

• Single-celled

• Create pseudopods (temporary projections of cytoplasm) to move and feed

• Feed via endocytosis (engulf organisms with pseudopods)

• Eg. Parasitic species Entamoeba causes dysentery

Ciliates

• Covered by cilia that move the organism

• Have a pellicle (rigid outer covering) that maintains their shape

• Aquatic and heterotrophs

• Eg. species Paramecium

• Food is swept into oral groove, food vacuole is formed, travels to lysosome and is digested

• Undigested food is discharged through anal pore

• Have two types of nuclei macronucleus (large) and micronuclei (smaller

• Reproduce via binary fission (asexual), and partake in conjugation

Sporozoans

• Produce spores during asexual phase of reproduction

• Non-motile, parasitic (obtain nutrients from body of host)

• Eg. genus Plasmodium - causes malaria

Plasmodium

• The life cycle of the pathogen involves two hosts: humans and mosquitoes

• Malaria can be treated with drugs, however it is more effective to eliminate the vector (mosquitoes)

• Malaria causes fever, chills, and internal organ damage

Life cycle of Plasmodium

1. Mosquito bites an infected human and takes up the Plasmodium sex cells

2. Sex cells join and make new individuals of the sexual form of Plasmodium

3. Sexual form of Plasmodium develops into a structure that produces many copies of the asexual form which are released into the saliva of the mosquito

4. Mosquito bites another human, releasing the asexual form of Plasmodium into the human

5. The asexual form of Plasmodium infects liver cells of the human

6. Asexual form multiples by asexual reproduction, eventually breaking the cell

7. The asexual form of Plasmodium infects red blood cells and continues to multiply by asexual reproduction

Fungus-like Protists

• Heterotropic

• Many are decomposers

• Three major phyla: 

  1. Acellular slime moulds

  2. Cellular slime moulds

  3. Water moulds

Plant-like Protists

• Contain chlorophyll and carry out photosynthesis

• Euglenoids

  • unicellular flagellates

  • Eg. Euglena - in sunlight autotrophic, in darkness, heterotrophic

• Algae

  • Single-celled or multicellular

bioluminescence

A chemical reaction that produces light energy within an organism's body. For a reaction to occur, a species must contain luciferin, a molecule that, when it reacts with oxygen, produces light.

good fungi

• baking (bread, cake etc.)

• Making wine/beer (yeast)

• Penicillin and other antibiotics

• Used to make cheese and Soy sauce

Bad Fungi

• Food spoilage

• Shower molds

• Ringworm (parasites)

• Athlete’s foot

characteristics of fungi

• Heterotrophic

• Eukaryotic

• Cell wall made of chitin

• Saprobes: absorb food from decaying matter

• Can be parasitic: feed on living organisms

• Absorption methods:

  • Endocytosis

  • Hyphae: threadlike filaments that grow into mycelium

Reproduction of fungi

• Both asexual and sexual by means of spores

• Spores are haploid

Categorized based on pattern of sexual reproduction

• Caselike Fungi

• Saclike Fungi

• Clublike Fungi

Caselike Fungi

• (Phylum: Zygomycota)

• Eg. hizopus ...AKA...bread mould

• Terrestrial saprobes

• Spores in caselike structure: sporangium

• Hyphae that extend into the food source: rhizoids

• Reproduction:

  • Asexual if favourable conditions

  • Sexual if unfavourable conditions

Saclike Fungi

• Phylum: Ascomycota

• Eg. mildew, truffles, some yeasts/moulds

• Spores in saclike (ascus) structure

• Reproduction:

  • Asexual: spores called conidia

    Tip of reproductive hyphae

  • Sexual: produces ascospores, dormant

Saclike Fungi; yeast

• unicellular, saclike

• Reproduction

  • budding (ideal conditions)

  • ascospores (poor conditions)

• Can carry out anaerobic respiration...

• Good: baking, beer, wine

• Bad: infections

Clublike Fungi

• Phylum: Basidiomycota

• Example: mushrooms, rusts, smuts, puffballs, bracket fungi

• Grocery store mushrooms!

• Saprobes or parasites

Plants characteristics

• Eukaryotic

• Multicellular

• Carry out photosynthesis (autotrophs)

• Have cell walls containing cellulose

• Develop from embryos protected by tissues of the parent plant

• Primarily live on land

• Can thrive in a variety of environments

• Sessile (can’t move from place to place)

Plant Life Cycles

• Plants go through an alternation of generations:

  1. One generation is haploid: gametophyte

  2. One generation is diploid: sporophyte

• Plants produce spores (haploid) which do not have to fuse with another cell. They can undergo division into a new plant- generation is haploid

• Haploid plants produce gametes which do fuse producing a diploid zygote, which grows into a diploid plant

Life Cycle

• In primitive plants: gametophyte generation dominates

• In seed producing plants - sporophyte generation dominates

Four main groups of land plants

1. Bryophytes

2. Pteridophytes

3. Gymnosperms

4. Angiosperms

Non-vascular Plants

Bryophytes: mosses, liverworts, hornworts

• Lack true roots, stems, and leaves

• Do not have specialized tissues to transport materials

• Grow in moist environments

Vascular Plants

Pteridophytes

• Have conducting tissues (xylem and phloem)

• Spore-producing vascular plants (club mosses, horsetails, ferns)

Seed Producing Vascular Plants

• Specialized organs (leaves, stems, roots)

• Produce either cones or flowers

Gymnosperms: cone producing (eg.conifers)

• Produce two types of cones - male and female

  • Male - pollen cones

  • Female - seed cones

• Wood is softwood: important export; industrial wood

Angiosperms

• Flower producing

• Reproduce sexually through pollination

• Seed develops into fruit

Angiosperm Life Cycle

Flower:

• Outer area made of sepals and petals

• Contains male and female parts

• Stamen (male reproductive part)

• Pollen (containing sperm) produced by anther

• Carpel - female reproductive part - at the base is the ovary which produces eggs

• Stigma - carpel opening

• Fertilization: pollen travels down style, sperm fertilizes egg

Self pollination

Pollen from same plant fertilizes same plant’s egg