BIOL2030 EXAM 1

york university

unicellular organisms

eukaryotic

protozoan

autonomous

specialized organelles

all needs in one cell

cytoplasmic level of organization

multicellular organisms

eukaryotic

metazoans

tissue formation

heterotrophic

sexual

ingestive

single unit that is part of a whole

mesozoans and parazoans

eukaryotic

multicellular but have no true tissues

combine both metazoan and protozoan traits

cytoplasmic level of organization

needs are in one cell

no tissues

specialized organelles

found in protozoa

cellular level of organization

colonial and unspecialized cells

multicellular; able to divide labor amongst themselves

NO tissues

cell-tissue level of organization

formation of tissues

cells come together for one function

makes up the extracellular matrix

tissue-organ level of organization

formation of organs

tissues come together to achieve common function

breakdown of supportive tissue and functional tissue

stroma

supportive tissue

found at the tissue-organ level of organization

parenchyma

functional tissue

found at the tissue-organ level of organization

organ-system level of organization

organs work together to power a whole system’s functions

associated with basic bodily functions (movement, digestion, etc.)

epithelial tissue

protective, covers a surface with a sheet of cells

muscular tissue

most common tissue in metazoans

used for voluntary and involuntary movement

nervous tissue

reception and conduction of stimuli via neurons

connective tissue

supportive, binds other tissues together

simple squamous tissue

epithelial

flat sheet of cells

useful for diffusion of gases

simple cuboidal tissue

epithelial

tubular/duct like shape

useful for secretion and absorption

simple columnar tissue

epithelial

tall columns of cells

useful for absorption

stratified tissue

epithelial

many sheets stacked/layered on top of each other

useful for tanking damage/protection

cells @ base of tissue push upward

pseudostratified tissue

epithelial

seems like tissues are stacked/layered but are not

useful for secretion, absorption, and molecular transport

transitional tissue

epithelial

stretchy

looks like many layers of stratified tissue but is only 3 very stretchy sheets

useful for absorption (holding in urine)

organ systems

there aren’t many of them, but even the minimal tissue types and organ systems are enough to drive a variety of bodily functions and a very complex organ system

intracellular space

within cell, one of two body fluids in eumetazoans

extracellular space

outside of cell, one of two body fluids in eumetazoans

interstitial fluid

one of two fluids in the extracellular space, directly surrounds the cell

blood plasma

one of two fluids in extracellular space, takes up most space in the extracellular space

structural elements in an organism

provide mechanical stability & protection

bones, cartilage, cuticles

body plans

can be limited by habitat, location, and ancestral history

animals in the same group can look very _________, and animals in different groups can look very __________.

different, similar

symmetry

the arrangement of body parts relative to body axis

symmetrical

can be split into identical parts along at least one plane

asymmetrical

no body axis and no plane of symmetry

some porifera and unicellular eukaryotes

spherical symmetry

no body axis (because it’s a sphere)

no polarity (all sides of a sphere are the same)

body parts seem to radiate from the centre/core of the organism

an infinite amount of planes of symmetry

only found in unicellular eukaryotes and asymmetrical animals

radial symmetry

one longitudinal body axis by which body is arranged around

cylindrically shaped

planes pass through the longitudinal axis

common in sessile species (porifera)

no front/backside, only an oral surface and aboral surface

can confront its environment in all directions

multiradiality

having radial symmetry through more than one plane

biradial (2 planes) quadradial (4 planes) pentaradial (5 planes)

bilateral symmetry

posterior to anterior orientation

midsaggital plane splits into two equal halves

cephalization present at anterior

anterior interacts w/ environment

dorsal (protective) and ventral (locomotive) surfaces

most common symmetry found

cephalization

the concentration of the nervous system into one area, usually the head

coelom

body cavity filled with fluid, found between outer body wall and gut

enables growth of organs, increases volume faster than surface area

cushions organs to prevent injuries

hydrostatic skeleton, great support for soft bodied organisms

ectoderm

outermost layer of body cavity

found in all metazoans

blastula (fluid found inside)

endoderm

gastrula within

found in cnidarians

diploblastic

mesoderm

innermost layer

tripoblastic

acoelomate

no coelom

no body cavity

mesoderm filled ectoderm

found in flatworms

pseudocoelomate

no coelom

fluid filled blastocoel (coelom of blastula) made of mesoderm lining the blastula/ectoderm

coelomate

true coelom

mesoderm forms cavity

can be schizocoelous or euterocoelous

consists of all other phylums post flatworms

schizocoelous

formation of cavity via the splitting of mesoderm

enterocoelous

formation of pinched pouches from the gut/digestive tract

unicellular eukaryotes

highly organized structures, specialized organelles

very complex

unicellular eukaryotes have primary economic importance because…

they are primary producers, the primary consumption, and decomposition

they impact animal health (some forms parasitic, gives diseases)

ciliary motion

type of locomotion in unicellular eukaryotes

hairlike growths along body wall

cilium propels water along the __________ allowing for directed movement

surface of attachment

water current created by ciliary motion is directed towards _______

cytostome (mouth)

ciliary movement can prevent…

a stagnant layer of water surrounding the body

metachronal beating

the coordinated beating of cilia during ciliary movement

imagine a crowd wave at a concert

ciliary power stroke

propels water, moves organism

ciliary recovery stroke

bend cilia to reduce resistance from flowing water and get back into position for power stroke

cilia can beat at an angle, making it move in a _______

forward spiral

cilia can beat in reverse as an ________

avoidance reaction

flagellar motion

moves water parallel to the axis of attachment in an undulating motion

can propel or pull the organism

tractellum

pulls the organism

flagellum moves water and food towards the body

undulation moves towards organism

pulsellum

moves organism like a tadpole

flagellum moves water away from body

undulation moves away from organism

amoeboid motion

movement via cytoplasmic streaming and lobopodia

cytoplasmic streaming

1. ectoplasm moves forward

2. as it moves forward, actin binding proteins change the composition of the ectoplasm into endoplasm

3. this creates an endoplasmic stream that moves the lobopodia forward

4. the stream fountains out at the semi solid hyaline cap at the end of the lobopodia

5. stream of endoplasm is formed into ectoplasm once more by polymerization via the crosslinking actin binding proteins

6. this creates a contraction of the lobopodia

autotrophs

self synthesized food

does not eat other organisms

heterotrophs

obtains nutrients from digesting other organisms

phagotroph

uses phagocytosis

ingests by engulfing organisms with pseudopodia

amoeboid phagocytosis

1. pseudopodia surrounds food particles

2. food particles are engulfed completely by the pseudopodia

3. now within the cytoplasm, a food vacuole is formed around the food particles

4. the food vacuole moves closer to the golgi body, where lysosomes approach the food vacuole and begin digestion

5. once digestion is finished, the food vacuole brings any undigested elements back towards the outer body wall

6. the food vacuole fuses with the body wall and the food particles are released

osmotroph

soluble food is absorbed via pinocytosis

endocytosis

the acquisition of material by a living cell via membrane invagination to form a vacuole

phenotypic plasticity

refer to the ability of genotypes to produce different phenotypes when exposed to different environmental conditions

euglena viridis exhibits phenotypic plasiticty when…

it is kept in the dark. euglena viridis is photoautotrophic and needs light exposure to produce its food. when kept in the dark, it becomes an osmotroph and gains its food via pinocytosis

t. vorax exhibits phenotypic plasticity when…

it is in the presence of t. thermophila. when in the presence of this organism, the t. vorax becomes larger in size and goes from non-selective feeding to highly selective feeding of the t. thermophila

exocytosis

a mode of excretion

endocytosis in reverse

digestive vacuole carries undigested material towards body wall and fuses with the cell surface to release the materials

passive diffusion

a mode of excretion

metabolic waste simply pass through the membrane

cytoproct

a butthole like pore

vacuole right next to it that fills up with waste material and is discharged through the cytoproct periodically

contractile vacuoles

regulates salt and water balance (osmoregulation)

contractile vacuoles are important to freshwater species because…

freshwater species aren’t able to use diffusion; if they did, the water uptake and ion loss could result in cell death

what goes inside contractile vacuoles?

1. protons (H+) from the proton pump

2. bicarbonate (HCO3-) from co-transport

3. H2O from passive water diffusion

4. H2CO3 formed by carbonic anhydrase combining bicarbonate and protons

filling and discharing a contractive vacuole depends on…

the ionic/osmotic gradient and how big the organism is

porifera

sessile and non moving filter feeders

exhibit cellular level of organization

cells are attached to the extracellular matrix (basal lamina) and to cell-to-cell junctions (adherens junctions/desmosomes)

spicules

skeletal structure of porifera

for architectural support

calcarea - porifera

calcium carbonate spicules

structural protein: collagen

habitat: marine/inshore

hexactinellida - porifera

6-rayed silica spicules

structural protein: collagen

habitat: marine/deep sea

demospongiae - porifera

spicules made of silica but aren’t 6-rayed

structural protein: spongin

habitat: freshwater/marine

homoscleromorpha - porifera

no spicules, but if they do have spicules, 4-rayed, uniform, small

structural protein: type IV collagen

habitat: marine/inshore

what level of organization do porifera exhibit

cellular, they have no tissues

totipotency/totipotent cells

the ability of cells to divide and reproduce any differentiable cell in the organism

archeocyte

totipotent amoeboid cell that receives food particles from the choanocyte and digests them

other types of totipotent cells

sclerocytes - make spicules

spongocytes - make spongin

collenocytes - make collagen

lophocytes - make collagen

choanocytes

ovoid shaped and flagellated with a collar (exposed end) and region embedded in sponge wall

line the cavities and canal systems of porifera

they are totipotent

what do choanocytes do

generate water current (with beating flagellum)

captures food (with collar microvilli and microfibrils)

captures sperm (with collar microvilli and microfibrils)

phagocytosis occurs at the base of the structure

asconoid

type of canal system architecture w/ flagellated spongocoel only

simplest canal system

small vase tube shape

calcarea only

syconoid

type of canal system architecture w/ flagellated canals only

large vase tube shape

calcarea only

leuconoid

type of canal system architecture w/ flagellated chambers only

complex arrangement, canals lead to chambers

large masses formed, resulting in no spongocoel

found in all other porifera besides calcarea

asconoid canal system structure

includes pinacocytes that create the pinacoderm as a covering/skin of the sponge

mesophyl, inner tissue that the pinacocytes and choanocytes are bound to, “nonliving” layer of sponge for structure

spongocoel, hollow chamber in the sponge that leads to the osculum

osculum, excurrent canal that discharges the flow of water through the ostium

ostium, incurrent canal that lets water through the sponge

choanocytes that altogether create the choanoderm (lining of choanocytes)

syconoid canal system structure

prosopyles, traps food particles

dermal ostium, incurrent canals that lead to radial canals

radial canals lined with choanocytes, leading to internal ostium

internal ostium leading to spongocoel

spongocoel absent of choanocytes, leads to osculum

osculum excurrent canal that discharges water flow from incurrent canals

leuconoid canal system structure

dermal ostium leads to incurrent canal

incurrent canal leads to flagellated chamber

flagellated chamber leads to excurrent canal

excurrent canal leads to osculum

hydrozoa - cnidaria

can be solitary or colonial

have polyp and medusa form

scyphozoa - cnidaria

solitary

absent or reduced polyp form

present medusa form

cubozoa - cnidaria

solitary

absent or reduced polyp form

present medusa form

anthozoa - cnidaria

can be solitary or colonial

present polyp form

absent medusa form

staurazoa - cnidaria

solitary

present polyp form

absent medusa form