BIOL 1P92 Final Exam Review

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

1. Triassic

2. Jurassic

3. 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

1. Hepatophyta (liverworts)

2. Bryophyta (mosses)

3. Anthocerophyta (hornworts)

4. Lycophyta

5. Pteridophyta

6. Cyadophyta

7. Ginkgophyta

8. Coniferophyta

9. 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

1. Multicellular and diploid

2. Zygotes and embryos are retained in maternal tissue

3. 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

1. Ectoderm

2. Mesoderm

3. 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