Unit 1 Organismal Bio

organismal Biology

ecological and evolutionary relationships between organisms (not just naming them)

Taxonomic groupings

groups based on similar characteristics that share evolutionary ancestry (domain, kingdom, phylum, class, order, family, genus, species)

Carl Linaeus

created binomial Latin-based system; “Linaeus System”a method for classifying and naming organisms using two names, genus and species (specific epithet)

rules for naming species Linaeus System

• capitalize genus

• lowercase epithet

• underline both, if type italicized

• we use latin bc dead language

• can name things in honor of someone “latinized”, but have to use actual name

• can’t name something after yourself

phylogenetic tree

takes evolutionary relationships and makes diagram to see where relationships are

paraphaletic group

grouping that does not include all of the descendants of a common ancestor (reptilia)

monophyletic group

includes common ancestor and all descendants of common ancestor

sister taxa

branches on phylogenetic tree right next to each other; considered to be closely related

basal taxa

unchanged, “prehistoric”, branched off early and doesn’t change

ancestral characteristics

similarity because of a shared common ancestry (like bones in whale, bat, human arm)

derived traits/characteristics

same characteristics but not from a common ancestor, from similar environments (evolution)

how old is the earth?

roughly 4.6 billion years old

when was the first sign of life on Earth?

3.5 billion years ago

what did the first living organisms look like

• very simple, unicellular organisms

• anaerobic (doesn’t need oxygen)

• prokaryotic (no nucleus/membrane bound organelles)

• we see this in chemical fossils

stromatolytes

• layered rocks, some of the prokaryotic cells stick together and from layers

• rocks are chemicals that cells metabolized, water added and sediment formed

• living cells are still present in some top layers with fossilized bottom

when did eukaryotic organisms begin to show up

• about 2.1 billion years ago

• membrane bound organelles

how did aerobic respiration begin

• cyanide organisms began to use sunlight to produce sugar and oxygen

• allowed for aerobic organisms (Still Prokaryotic)

Endosymbiosis

• membrane folds inward, encounters DNA, folds around it to make nucleus, ER

- can engulf photosynthesis cell

• one cell engulfs another and helps the cell work; one cell process sugars, make atp, one cell engulfs this

Endosymbiotic Theory

small ancestral cells engulfed another; this cell helps the other cell, becoming a eukaryotic organism

• chloroplast and mitochondria have individual DNA

When did multicellular organisms appear

1.4 billion years ago

how did multicellular organisms form

• unicellular grouped together in colonies, worked together

• portions of colony specialized in specific activities

• some cells stopped doing other functions, focused on one particular job- specialization

• cells can’t survive on their own

• ex. Portuguese man-o-war is colonial organism

first animal evidence of multicellular organisms

1 billion years ago- 650 million years ago

• 1 BYA trace evidence of burrows, tracks (small soft-bodied organisms)

• 650 MYA fossilized ex of jellyfish, coral relatives

When did land plants show up

as recently as 500 million years ago

When was the first evidence of air breathing land animals

430 million years ago (defenitive fossil)

Plant characteristics

• organisms that are (mostly) multicellular

• (mostly) autotrophic

• have a cellulose wall

• store their food as a starch

• contain pigments chlorophyll A,B and carotenoids

• have a life cycle that alternates between a haploid (gametophyte) and diploid (sporophyte)

how many species of plants are there

• roughly 400,000 species of characteristics

• 150 are important food plants

• 11 species provide 75% of human diet (most are grasses)

plant uses

• medicines (aspirin comes from bark of specific type of willow tree)

• caffeine

• plants make oxygen

• raw materials

• erosion control with plants

Plant Domain, Kingdom

• all plants on domain Eukarya

• most plants are in Supergroup Archaeplastida and Kingdom Plantae

Green algaes

• Phylum Chlorophyta

• 2 classes; Chloropsida and charopsida

• cloropsida- some unicellular, some filamentous; colonial and multicellular

• charopsida- multicellular

unicellular (class chloropsida)

• Genus chlamydomonas

• can produce asexually and sexually

• asexual split in half, sexual gametes are + and - not distinct male/female; fuse together and form a zygote

ex

• micrasterias (desmids)

• acetabularia- single- celled algae that can grow up to 10 cm long

filamentous (class chloropsida)

• can be unbranched or branched

• unbranched: Spirogyra- spiral shaped chloroplast

• branched: Cladophora

• goes through conjugation- 2 filaments next to each other, outgrowth will form and fuse 2 cells together, 2 nuclei become 1, forms zygote

Colonial (class chloropsida)

ex- volvox

• volvox- spherical algae

• all cells grouped together, flagella work together to move

• asexual reproduction if conditions are favorable; parent cells break out of adult colonies, go to middle and make new colonies

multicellular (class chloropsida)

• more than one cell, fused together and can’t live on own

ex

• ulva (sea lettuce)

• utilizes both forms of reproduction no matter the conditions- alternation of generations (2 modes rep. always both part of cycle)

class charopsida

• still green algae

• chara- “stone wart”; closest extant relative to plants

• multicellular

• charophytes basal taxon

nonvascular vs vascular

• nonvascular- plants do not have tissues that carry water and other materials, instead use osmosis and diffusion

• vascular- plants have tubes that are used for transportation

plant reproduction gamete types (3)

• isogamy- plants with isogameous gametes, not distinctive male/female; same size/identical, just +/-

• anisogamy- not the same gametes; small and large gametes; generally small male, large female; both have flagellum, may or may not be mobile

• oogamy- small but mobile male, large immobile female

Alternation of Generations

2 separate phases of reproduction; 2 distinct body forms in those plants

sporophyte vs gametophyte

• sporophyte- diploid part of cycle (2n); produces spores through meiosis

• gametophyte- haploid part of cycle (n); spores grow into gametophytes, produces gametes through mitosis, fertilization occurs, forms zygote, sporophyte

-in mosses gametophyte portion of life cycle is dominant; sporophyte part of the cycle becomes more dominant as things become more evolutionary advanced

homosporous vs heterosporous

• homosporous- single gamete will produce male and female parts

• heterosporous- 2 types of gametes, each will produce male/female parts

spores vs seeds

• spores are single cells; can only grow into gametophyte

• seeds formed from gametes infused together; seed is embryonic plant w/ nutrients to survive (zygote as seed is forming)

non vascular plants

• 3 phyla- hepaticophyta (liverworts), anthocerotophyta (hornworts), and bryophyta (mosses)

• all homosporous alternation of generations

• terrestrial, but need water for sexual reproduction

• uses: peat moss important fuel, animals use mosses and other plants as nests, stabilize soil and prevent erosion

Phylum Hepaticophyta

• liverworts

• most primitive type of nonvascular plant (flattened leafy structure)

• Thalos Liverwort- stringy/mossy looking liverwort

• genus Marchantia- trees on it with gametophyte structures, female gametophyte houses archegonia, male houses antheridium, Gemma cup

• Gemma cup- produces Gemma, indep. structures used for asex. rep. (can be thrown out of plant and make new plant)

phylum Anthocerotophyta

• hornworts

• sporophyte grows out of gametophyte like horns

• homosporous

• ex: genus Anthoceros

Phylum Bryophyta

• mosses

• can look like vascular plant

• rhizoids used for anchoring plant (root-like) but doesn’t draw water

• dioecious (separate male/female plants)

• use homosporous alternation of generations

• sporophyte grows out of female gametophyte, produces spores, operculum pops off to release spores; disperses spores and grows into new gametophyte

• male sperm must blow into female archegonia to form sporophyte

mitosis vs meiosis is plants

• mitosis makes gametes

• meiosis makes spores

Vascular plants

• showed up around 420 mya

• vascular tissues- xylem and phloem

• xylem- conductive tissue that moves h2o and minerals up

• phloem- conductive material that takes glucose and moves it down from leaves into other areas of plant

glucose can be immediately oxidized for energy (cell resp), transported as sucrose (dissach), store glucose in amyloplasts (starch, energy for later; cellulose, structure)

cooksonia

• earliest known vascular plant

• stems with sporangia

• dichotomas branching- branches breaking off that look similar

• extinct

evolution of leaves

• prophylls- primitive leaves

Enation theory

-began to see small branching that didn’t grow into other stems on a plant like cooksonia: PROPHYLL

-over time, prophyll structure starts to open up, begin to see tiny strands of vascular tissue: MICROPHYLL

-one branch begins to dominate the stem system, the side branches begin to flatten out into a single plane, tissue grows between branches on the same plane creating a leaf : MEGAPHYLL

-branched vascular tissue

Seedless Vascular Plants

• only spores

• phylums lycophyta and pteridiophyta (subphylum psilophyta, equisetophyta, and polypodiophyta)

• still need some water for sexual rep.

• homosporous and heterosporous alt. of gen.

Phylum Lycophyta

• club mosses and quillworts

• hom. and heterosporous alt. of gen.

• rhizome- horizontal underground stem

• true roots branch off rhizome

• seedless vascular

3 Genera

• Lycopodium (club moss); homosporous, strobilis (elongated top portion), microphylls (texture on stem), lycopodium spores very flammable, used to be used for flash photography still used for theatrical fireworks

• Selaginella; heterosporous alt. of gen.

• Isoetes (quillwort); longer microphylls, sporangia at bottom, not all on stem, heterosporous

Phylum Pteridiophyta Subphylum Psilophyta

• whisk ferns (not true fern)

• homosporous alt. of gen.

• only group of vascular plants w/out true roots (only rhizoids)

• small prophylls

• sporangia at base of some prophylls

Phylum Pteridiophyta Subphylum Equisetophyta

• genus Equisetum

• homosporous alt. of gen.

• strobilus on equisetum not formed by mini prophylls

• reduced microphylls (nonfunctional)

• types: Horsetails (floofy, without floof structure would look similar to scouring rushes, except whorls); Scouring rushes (have silica deposits SiO2, bits of sand inside cells, used to scrub pans long ago

• Equisetum Strobilis- composed of multiple sporagiophores

—spores wrapped in strands of protein called elaters (elaters and spore dry out, elater becomes rigid to fling spore out and help it grow away from parent)

Phylum Pteridiophyta Subphylum Polypodiophyta

ex:

-marsilea: four leaf clover

-azolla: aquatic form

-cyathera: looks like fern palm tree

• ferns very diverse

• sori- clusters of sporangia on underside of plant leaves, some plants grow separate stalk, some grow little stem with clusters of sporangia

typical woodland ferns

• fiddleheads- new fern frond, wrapped in ball that unwinds as it grows

• indusium- covers spores to keep safe, some will shrivel and dry when sporangia mature so they can fling spores into environment

fern gametophyte

• homosporous alt. of gen.

• both stages won’t be visible together b/c goal is to increase genetic diversity so fern won’t self-fertilize

• new sporophyte grows in cleavage area where archegonia are

• heart-shaped prothallus is fern gametophyte

parts of sporangia

• annulus- thick walled, heavily structured cell

• lip cells- thin cells that will burst open to allow sporangia to release spores

strobilis vs sporangriophores vs sporangia vs spore

strobilis- multiple sporangiophores

sporangiophore- multiple sporangia

spores located in sporangia