Protozoa have what type of cell structure?

Eukaryotic

Nucleus

contains genome & is surrounded by a double membrane separating it from the metabolic machinery of the cell

Mitochondria

contain DNA and enzymes for aerobic respiration

Chloropasts

contain DNA and are the sites of Photosynthesis

Endoplasmic reticulum

functions in the synthesis of carbohydrates, lipids, and when ribosomes are present, protiens

Golgi Body

a stack of flattened vesicles that receive the products of the endoplasmic reticulum, then modifies and releases them in vesicles for transport elsewhere

Lysosomes

Golgi-derived, membrane bound vesciles that contain enzymes for intracellular digestion

Cytoskeleton

• composed of actin filaments (microfilaments) and microtubles
• Typically a three-dimensional network & responsible for the maintenance of cell shape
• essential for cell motility by transmitting force from one part of the cell to another resulting in movement.

Cell membrane

• phospholipid bilayer that separates the internal cell environment from the exterior, thereby regulates the biochemical conditions of the cell's interior for the processes of life
• Protiens span cell membrane or be attached to it
• glycocalyx forms a template on which the exoskeleton is secreted & regulates binding to signal molecules

Cell Motility - Ameboid Movement

• outer cytoplasmic rind (ectoplasm) of a stiff gel
• inner cytoplasm (endoplasm) is a fluid sol
• rear contraction hypothesis - rear contraction forces the endoplasm forward by compressing it
• front contraction hypothesis - front contraction pulls the cytoplasm forward by exerting tension, via the cytoplasm, on the trailing part of the cell

Cell Motility - Flagellar movement

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Endocytosis – the bringing is of extracellular materials entering through minute pits in the cell’s membrane that later pinch off internally 

Circulation in Cells - Cyclosis

Cyclosis - vesicles in a circuit, typical of Paramecium

Micropinocytosis - brings in water, ions, and small molecules

Macropinocytosis (Uptake / release by cells)

Macropinocytosis - brings in proteins and other macromolecules

Phagocytosis - (Uptake / release by cells)

Phagocytosis - requires binding of a particle to membrane receptors & dynamic alteration of the cell membrane involving the actin cytoskeleton

Exocytosis - process of releasing indigestible material from the cell by the fusion of the residual vacuole with the cell membrane

Mucous - cell secretions

Mutualism - Symbiosis

both species benefit

ex: termites & Protozoa (live in gut track of termites and assist in digestion) 

Commensalism - Symbiosis

one species benefits, the other is unaffected

ex: clownfish / sea anemone. Fish lives among tentacles protected from predators.

Parasitism

one species benefits, the other is harmed

ex: tapeworms and host

Competition

Neither Species Benefits

Neutralism

both species are unaffected

Amebas Pellicle

(body wall of protozoan)

 dense mesh of protiens in the outermost cytoplasm

Euglenoids Pellicle

(body wall of protozoan)

Pellicular microtubles arranges as a corset

Heliozoans Pellicle

(body wall of protozoan)

microtubles originate on the flagellar basal bodies and radiate rearward to the opposite extremity as a sort of axial skeleton

Ciliates Pellicle

(body wall of protozoan)

vesicles, know as alveoli, occur immediately below the cell membrane; alveoli may be turgid and help support the cell, may store Ca++ which can be released to trigger cellular responses

Dinoflagellates Pellicle

(body wall of protozoan)

plates of cellulose secreted into the alveolar vesciles forming a rigid endoskeleton

Spongiome

is an array of cytoplasmic vesicles or tubules

Osmoregulation

The active regulation of osmotic pressure of bodily fluids to maintain the homeostasis of the bodys water content.  

Clonal (asexual)

Fission

of parent into two or more daugther cells

Binary Fission

when the process results in two simialr progeny cells

Budding

when one progency is much smaller than the other

Multiply Fission

when the division of the parent results in more than two daugther cell

Schizogony

a specialized form of multiple fission in which repeated division of the nucleus precede cell division

Mitotic Division

Open Spindle

occurs in animals - nuclear membrane disintegrates during mitosis as the chromosomes condense and attache to the mitotic spindle

Mitotic Division

Closed Spindle

occurs in protozoans - nuclear membrane does not break down during mitosis and the spindle forms within the mucleus; regarded as the primitive form of mitosis in eukaryotics cells

Haploid Dominance

sexual reporduction

two individuals mitotically produce isogames which fuse to form a diploid zygote that then undergoes meiosis to the heploid form

ex: Volvocida, many dinoflagellates, axostylates and sporozoans

Diploid Dominance

sexual reproduction

diploid (2N) individuals meiotically produce N gametes which fuse restoring a diploid individual

ex: axostylates, heliozoans, green algae, diatoms, ciliates and multicellular animals

Haploid-diploid Dominance

sexual reporduction

co-dominant life cycle stages diploid individuals meiotically produce haploid spores that develop into haploid individual that form haploid gametes that fuse retoring the diploid individual.

many algae and multicellular green plants

Epithelium

Metazoa

consists of cells that adjoin one another to form a sheet that covers the body or lines an internal cavity (cuticle covers body epidermis)

Connective Tissue

Metazoa

consists of widely seperated non-adjoining cells in the extracellular matrix - most common protein is collagen

Extracellular matrix

metazoa

can be modified to form a skeleton

Fragmentation

metazoa asexual reproduction

body breaks into pieces

Fission

asexual reproduction in metazoa

more orderly division of the body along longitudinal or transverse axis.

Parthenogensis

asexual reporduction of metazoa

development of an individual from an unfertilized egg or other totipontent cell

(Totipotency is the ability of a single cell to divide and produce all the differentiated cells in an organism, including extraembryonic tissues. )

Holoblastic Cleavage

Metazoa

the first two division planes of the zygote are typically parallel to the animal-vegetal axis and the entire zygote is cleaved into two and then four blastomeres.

Microlecithal eggs

Sexual Reproduction Metazoa

little yolk distributed equally - holoblastic cleavage

Mesolecithal eggs

sexual reproduction - Metazoa

contains moderate amount of yolk restricted to vegetal hemisphere - Holoblastic cleavage

Meroblastic Cleavage

incomplete cleavage - occurs in a specific region of the eggs surface, Initially cleavage-furrow membranes are incomplete and do not fully isolate the cytoplasm of the blastomeres from the underlying yolk mass

Macrolecithal eggs

sexual reproduction - metazoa

large and very yolky - meroblastic cleavage

Heterochrony

Changing of the timing of developmental events

Pedomorphosis

Part of Heterochrony

The trait of the descendent species resenbles an ancestral developmental trait and thus is a larval or juvenile form; often results in descendants that are smaller and anatomically simpler than their ancestors

Progenesis

Heterochrony -> Pedomorphosis

Neoteny

Heterochrony --> Pedomorphosis

Postdisplacement

Heterochrony --> Pedomorphosis

Peramorphosis

from - Heterochrony

the trait of the descendant species develops to an extent beyond that found in the ancestor; typically results in ancestors that are larger and anatomically more complex than their ancestor

Hypermorphosis

Heterochrony --> Peramorphosis

developmental rate and somatic onset are unchanged, but developmental period is extended and the onset of gonad differentiation is delayed

Accelaration

Heterochrony --> Peramorphosis

developmental period and onset are unchanged, but rate of somatic differentiation is increased

Predisplacement

Heterochrony --> Peramorphosis

developmental period and rate are unchanged,  but onset of differentiation is early

 Colonial Theory

hypothesizes that metazoans are dervied from a colony of flagellated protozoa

Asconoid

Proifera

simple cylinder about 1mm in diameter; limits sponges to small body size

Synocoid

proifera

up to about 1cm in diameter, w/ alternating surfaces inpockets w/ inteiror out-pockets

 Leuconoid

up to about 1m or greater, w/ thousands of spherical chambers w/ flagellar pumps; water volume is restricted to minute capillary like vessels that enter and leave the chambers

Pinacoderm

synocoid design

composed of two types of differentiated cells

Mesophyl

synocoid design

Only later of sponge not bathed in environmental water

Choanoderm

(sponges)

consists of flagellated collar cells or choanocytes; generates the water flow through the sponge

Lueconoid

Lack the sheet-like pinacoderm pavement  that covers the body; in its place is a trabecular syncytium, with the membranes that normally separate cells absent and the cytoplasm continuous and uninterrupted throughout the syncytium

Water Pumping in sponges

sponge pumps a volume of water equal to its body volume once every 5 seconds