Studied by 10 people
Looks like no one added any tags here yet for you.
How long ago our solar system began
4.6 billion years ago
When the Big bang occurred
13.8 billion years ago
When life emerged on earth
4-3.5 billion years ago
Fossils
Preserved remains of past life on earth
Radiometric dating
Fossils can be dated using elemental isotopes in accompanying rock.
Half life
The length of time required for a radioisotope to decay to exactly one half of its initial quantity.
Measure the amount of a given isotope and the amount of decay product.
Bias in fossil record
Anatomy
Size
Number
Environment
Time
Geological processes/ paleontology
Why is anatomy a bias in the fossil record
Hard body parts are better than soft ones
Why is size a bias in the fossil record
Larger fossils are found more easily
Why is number a bias in the fossil record
There is more abundance while alive
Why is the environment a bias in the fossil record
Fossils living near the water are better than those inland
Stromatolites
layered rock formed when miccroorganisma bind particles of sediment together, forming thin sheets.
Hypothesis of the origin of eukaryotic cells
SYmbiotic relationship between ancient bacteria and archaea
Symbiosis
2 species live in direct contact
Endosymbiosis
One organism lives inside another host.
Multicellularity
evolved several times, producing lineages of several algae and ancestors of fungi, plants, and animals
2 possible origins of multicellular eukaryotes
Individuals form a colony
Single cell divides and stick together
What era the multicellular eukaryotes evolved in
Proterozoic
What were the first animals
Invertebrates
When did multicellular animals emerge
Towards end of proterozoic era
Burgess shale
site where many fossils from the Cambrian period were found with minimal decomposition.
Cambrian explosion
Increased diversity in animal species
Permian extinction
Marks boundary between paleozoic and Mesozoic eras.
Mesozoic era/ phanerozoic eon
Age of the dinosaurs
3 periods of the mesozoic era
Triassic
Jurassic
Cretaceous
Which period of the mesozoic era had the mass extinction of dinosaurs
End of the Cretaceous period
Cenozoic era
Diversification of birds, fish, insects, and flowering plants occured.
When did hominoids appear
About 7million years ago
Common shapes of prokaryotic cells
Spherical
Cylindrical
Spiral
Comma-shaped
Prokaryotic Cell-wall: Gram-positive
Single, thick, peptidoglycan layer
Prokaryotic Cell-wall: Gram-Negative
A thin peptidoglycan sheath surrounded by an outer lipopolysaccharide membrane.
Flagella
Rigid helical proteins that rotate like propellars
Pili
Rigid shafts of protein extending from cell walls
Help flagella adhere to other cells
Antibiotic
Natural or synthetic substance that kills or inhibits the growth of bacteria
Biofilm
Complex aggregation of microorganisms attached to the surface and surrounded by a film of polymers.
When is biofilm harmful
When attached to surgical equipment and supplies
When is biofilm beneficial
When used in sewage treatment plants or in cleanup of toxic organic molecules in groundwater.
What conditions do the domain bacteria favour
Most bacteria favour moderate conditions, however some are extremophiles
Bacteria relationships
Many form symbiotic relationships with eukaryotes.
Symbiotic relationship
Both organisms benefit from the relationship
Cyanobacteria
Photosynthetic bacteria
Abundant in freshwater, oceans, wetlands, and on surfaces of arid soils.
Named for cyan/ blue-green color
What is the only prokaryote that generates oxygen as a product of photosynthesis
Cyanobacteria
Gave rise to plastids of eukaryotic algae and plants
Cyanobacteria
What conditions domain archaea live in
Archaea are extremophiles, but many also live in moderate conditions.
Extremophiles
Can occupy environments with extreme conditions
Ex. high salinity, acidity, methane, or temp.
What allows archaea to be extremophiles
Ether-bonded lipids are more resistant to heat
Methanogens
Methan generators
Live in low-oxygen environments
Obligate anaerobes
Kingdom plantae
Multicellular eukaryotic organisms are composed of cells having plastids.
Primarily live on land
Where do plants evolve from
Green algal ancestors that lived in aquatic habitats (protists)
Adapted to terrestrial life
Streptophytes
Modern plants and their closest green algal relatives.
Derived traits that streptophyte algae and land plants share
Distinctive types of cytokinesis
Plasmodesmata
Sexual reproduction using egg and smaller sperm
Distinctive features of land plants
Bodies composed of three-dimensional tissues
Tissues arise from apical meristems at growing tips
Able to produce thick, robust bodies
Tissues and organs have specialized functions
Distinctive reproductive features of Land pants
Two types of multicellular bodies alternate in time (Alteration of generations)
The sporophyte embryo is nourished and protected by maternal tissues
Sporophytes produce tough-walled non flagellate spores that survive dispersal through dry air.
Sporphyte
Diploid generation produces haploid spores
Gametophyte
Haploid generation produces haploid gametes through mitosis
9 Plant phyla
Hepatophyta (liverworts)
Bryophyta (mosses)
Anthocerophyta (hornworts)
Lycophyta
Pteridophyta
Cyadophyta
Ginkgophyta
Coniferophyta
Anthophyta (angiosperms/ flowering plants)
Bryophytes include which phyla
Hepatophyta (liverworts)
Bryophyta (mosses)
Anthocerophyta (hornworts)
Seedless vascular plants include which phyla
Lycophyta
Pteridophyta
Gymnosperms include which phyla
Cyadophyta
Ginkgophyta
Coniferophyta
Gametangia
Protects developing gametes from drying out and/or microbial attack
Antheridia
Spherical/ elongate gametangia producing sperm
Archegonia
Flask-shaped gametangia enclosing an egg.
Seedless vascular plants
Possess vascular tissue
Do not possess seeds
Known as tracheophytes
What vascular tissues are
Internal water and nutrient conducting tissues
Also provide structural support
Stems
Possess leaves and sporangia
Contain xylem and phloem
Roots
Specialized for uptake of water and nutrients from soil
Leaves
Photosynthetic function
Cutie
Helps block pathogens
Found in cuticle
Stomata
Pores that open and close to allow gas exchange while minimizing water loss.
What endosporous development provides
Provides increased protection for gametes and developing embryo later on.
Endosporous development
Gametophytes produced by spores develop inside the spore wall
Occurs in many heterosporous plants
Pollen grains produce;
Nonmotile sperm
Pollination
Transfer of pollen to female reproductive parts
Ovule
An egg developing inside a gametophyte that is retained in the spore wall and inside the integument and megasporangium tissues.
Important reproductive advantages of seeds
A key adaptation to reproduction in land habitat
Able to remain dormant in soil and wait for favourable conditions
Adaptations to improve dispersal
Can store considerable amounts of food
Sperm can reach egg without swimming through water.
Angiosperms
Flowering plants with seeds
Most ecologically diverse plant on earth
Who do pollinators co-evolve with
Pollinators undergo co-evolution with angiosperms
Heritable changes in one affects the other
Importance of plant embryos
Charophyceans lack embryos
One of the first critical innovations of land plants
Plant embryos are young sporophytes developed from zygote’s
3 Features of plant embryos
Multicellular and diploid
Zygotes and embryos are retained in maternal tissue
Depends on organic and mineral materials supplied by the mother plant
Origin of land plants was key to;
Development of substantial soils
Rise of modern levels of atmospheric oxygen
Evolution of modern plant communities
Colonization of land by animals
Characteristics of an animal
Multicellular eukaryotes
Lack cell walls
Heterotrophs
Motile at some point in their lives
Reproduce asexually or sexually
Extensive extracellular matrix provides structural support
Animal modes of feeding
Suspension feeding
Bulk feeding
Fluid feeding
Suspension feeding
Filtering particles from water
Bulk feeding
Eating large food pieces
Fluid feeding
Sucking sap or animal body fluids
Metamorphis
Animal changes from juvenile to adult form
What era did multicellular animals emerge in
End of proterozoic era
Key innovations in animal evolution
Tissue development
Body symmetry
Body cavities
Patterns of embryological development
Segmentation
3 Primary cell layers in embryos
Ectoderm
Mesoderm
Endoderm
Ectoderm
Outermost cell layer of embryo
Forms external covering and nervous system
Mesoderm
Middle cell layer of embryo
Forms muscles of the body wall and other structures between gut and external covering
Endoderm
Innermost cell layer of embryo
Forms lining of gut
Types of body planes
Diploblastic
Triploblastic
Diploblastic body plane
Based on 2 embryonic layers (endoderm and ectoderm)
Triploblastic body plane
Have all 3, clearly identified germ layers
Most animals
Radial symmetry
Body parts are arranged around a central axis
Bilateral symmetry
Mirror image along midline of the body
Most animals
Leads to development of a head/ cephalization
Acoelomate animals
No body cavity
Ex. flatworms
Pseudocoelomate animals
Body cavity is not completely surrounded by mesoderm
Ex. roundworms
Coelomate animals
Have a coelom-fluid-filled body cavity entirely lined by the mesoderm.
Mesenteries surround inner organs
