Lecture 3: Architecture & Body Plans

Bauplan (Body Plan)

structural design of an animal or parts of an animal

Body plans develop ___ in life and are _______

early (embryonic), evolutionarily conserved

Basic Animal Requirements

• acquire, digest, metabolize food

• distribute nutrients

• obtain and distribute oxygen

• get rid of metabolic wastes and undigested materials

• reproduce

Symmetry

regular arrangement of body structures relative to a body axis

Example of an Asymmetrical Animal

Sponges

Radial Symmetry

general form of a cylinder with one main axis. Any plane of sectioning passing along this axis produces similar halves

Multiradial Symmetry

many possibilities including Quadriradial (jellyfish) and Pentaradial (Starfish) Symmetry

When a gut is present, the axis pass from the ____ to the ____

oral surface, aboral surface

aboral

end of organism without mouth

Body Parts oriented about a single medial axis from ____ to ____ end

anterior, posterior

Cephalization

concentration of sensory and feeding structures at anterior end

Radial Symmetry is common in animal who must…

confront environments from all directions (sessile, sedentary, and planktonic)

Bilateral symmetry is common in animals with…

anterior end confronting the environment

How simple organisms exchange materials with their environment

all cells rely on diffusion for exchange

all adult structures develop from _____

embryonic germ tissue layers

ectoderm

outer layer

Endoderm

inner layer of embryonic germ

Epidermis is derived from ___

ectoderm

Gastrodermis is derived from ___

Gastrodermis

Diploblastic

having only two layers of cells (endoderm + ectoderm)

Triploblastic

having three layers of cells (mesoderm between endoderm and ectoderm)

Triploblastic animals can be distinguished based on the presence of ______

a fluid filled body cavity between the gut and the body wall

Acoelomate

no body cavity; mesoderm develops into a mass of tissue (mesenchyme)

Blastocoelomate

fluid filled body cavity not derived from mesoderm, and not enclosed with peritoneum

Blastocoelom

a fluid filled body cavity that is not derived from mesoderm, rather from Blastula

Coelomate

true fluid filled body cavity derived from mesoderm and enclosed with peritoneum

Coelom

true fluid filled body cavity derived from mesoderm

Peritoneum

separates organs from coelom

3 Locomotor patterns in Metazoa

1. Ciliary and flagellar movement

2. Hydrostatic propulsion

3. Locomotor limb movement

3 types of support systems

1. structural endoskeletons

2. structural exoskeletons

3. hydrostatic skeletons

Cilia

numerous, in tracts or patches

Flagella

long, occurs singly in pairs (ex:sperm)

Function of Cilia and Flagella

• their movement creates a propulsive force that moves a small animal through fluid, or creates water flow over larger/sessile animals

• gas and nutrient exchange

• sensory structures

Ciliary Beating

the power stroke and recovery stroke of cilia, the coordinated beating leads to mechanical waves

Some Flagella beat _____, others beat in a ________ pattern

back and forth, helical

Hydrostatic Skeleton

in soft bodies invertebrates; fluids under pressure

Rigid Skeleton

endoskeleton or exoskeleton

Soft bodied invertebrates use __________ to change their shape for use in locomotion

alternate contraction and reaction of different muscle groups

Rigid Skeleton animals contrasted with Hydrostatic skeleton animals

animals with a rigid skeleton are less flexible, but can grow larger, have more controlled/faster movements, and better defensive against predators

Spicules

Calcareous Test

Cuticle

nonliving external layer of an animal

Different structure and composition of arthropods and insects

• arthropods: proteins + chitin

• insects: wax

Digestion

breaking down food by hydrolysis into smaller units (nutrients)

Extracorporeal

outside the body

Extracellular

in a gut chamber

Intracellular

within a cell

Two ways that food/nutrients enter cells

1. Phagocytosis → uptake of food particles/microbes

2. Pinocytosis → uptake of dissolved organic matter

Blind ended/incomplete digestive tract

complete digestive tract

Animals can be categorized by:

• type of food: herbivore, carnivore, omnivore, detritovore

• Size of food: microphages, macrophages

• mode of feeding: grazers, predators, scavengers, deposit feeders, suspension feeders

Suspension-feeding

capture of particles (plankton, detritus, microbes) suspended in water → all are omnivores and microphages

Three steps of Suspension feeding

1. move water past feeding structures, or extend structure in moving water

2. capture particles

3. transport to mout

Setal-Net

feeding appendages that contains rows of feather-like setae, that are swept through water or kept still in moving water (ex: planktonic/ benthic crustaceans)

Mucous Net

patches or sheets of mucus used to trap particles that are then ingested (ex: annelids & gastropods)

Ciliary-mucous capture

particles captured on mucous sheets are transported by rows of cilia (ex: bivalves, fan worms, echinoderms)

Tentacle or Tube-feet Suspension Feeding

larger particles are captured by the tentacles or tube feet of cnidarians or echinoderms (mucus MAY be involves)

Deposit Feeding

the ingestion of sediment or soil to digest organic matter (ditritus, diatoms, fecal pellets, microbes) within it

Stalkers

predators that are motile, actively pursue prey

Lurking Predators

predators that are motile, sit and wait for prey to come and quickly seize it. Many hide in burrows and crevices, some build traps or pits

Sessile/Drifting Opportunists

non-motile or drifting and wait for prey to come and quickly seize it

Grazers

predators that move along substrate and pick at epifauna. Diet consists of mainly slow-moving or sessile animals

Excretion of nitrogenous waste products is associated with _____

osmoregulation

osmoregulation

control of ion and water balance in body fluids

Deamination of amino acids produce…

residues that can be formed into the following excretory compounds:

• ammonia

• Urea

• uric acid

difference between Ammonia, Urea, and Uric Acid

• ammonia → toxic, highly soluble

• urea → less toxic, rare in inverts

• uric acid → low toxicity and solubilityA

Ammonia

produced in most marine and freshwater inferts; diffuse through tissues, and is rapidly diluted in water

→ animals with no excretory organs are restricted to aquatic habitats for this reason

Uric Acid

used by terrestrial invertebrates that must conserve water, and converts nitrogenous waste to a less toxic and less soluble form. This requires energy, but allows success on land

Osmoregulation

lots of words idk check slide 54

• Freshwater animals are ____ with respect to their environment, tend to _____

• Terrestrial animals are ____ with respect to their environment and subject to ______

• hypertonic, gain water and lose salts

• hypotonic, water and salt loss

Osmoregulators

maintain body fluid concentrations regardless of eternal conditions → some freshwater crustaceans and annelids

Osmoconformers

allow body fluids to vary with changes in external salinity → any estuarine animals

Stenohaline

tolerate a narrow range of salinities

Euryhaline

tolerate a wide range of salinities

Nephridia

tubular organ found in many invertebrates that functions like a primitive kidney to remove metabolic waste and balance water level

Protonephridium

tubular structure with nephridiopore, terminating into cup-shape cap cell

Flame Bulbs

a cap cell on the protonephridium that have tufts of cilia

Solenocytes

a cap cell on the protonephridium that have 1-2 flagella

Metanephridium

multicellular, and open to body fluids as well as the outside environment. Features a ciliated funnel that collects fluids, non-waste components are re-absorbed back through walls of bladder/duct

Nephrostome

the cilated funnel in the metanephridium that collects fluids, non-waste components to be re-absorbed back through the walls of bladder or duct

Excretory structure in Crustaceans

have antennal glands

Excretory structure in insects and spider

Malpighian tubules

Gas exchange must take place on _____ surfaces

wet

Circulatory Fluids

transport O2 and CO2 and exchange with environment

integumentary/ cutaneous gas exchange

exchanging of gases through body surfaces

→ restricted to aquatic/damp terrestrial environments (cnidarians, flatworms)

book lungs

exchange surfaces in spiders to retain moisture

Trachea

chitin-lined tubes taht extend into tissues that is connected to its exoskeleton; used in instects

Pneumostome & lungs

gas exchange surfaces used in land snails and slugs adapted to retain moisture

Respiratory Pigments

binds reversibly to O2 and can be used to store O2 → all contains metal

Hemoglobin

most common oxygen carrying pigment, occurs in a variety of invertebrates

Hemocyanin

an oxygen carrying pigment that is common in molluscs and anthropods

Respiratory pigments are _____ in insects

rare

Examples of Mechanoreceptors and non-mechanical receptors

mechanical: touch, pressure, vibration, ect

non-mechanical: chemicals, light, temperature, magnetism

Tactile Receptors

modified epithelial cells, often with projections (bristles, setae, bumps)

Georeceptors (statocysts)

a tactile receptor that responds to the pull of gravity

Phonoreceptors and Chemoreceptors are found in _____ or on ____

pits, ‘hairs’

Types of Photoreceptors

• eyespots/ ocelli (simple)

• compound eyes (arthropods)

• complex eyes (cephalopods)

Nervous system in Radially stem metrical animals

nerve net → no centralized “brain” structure, nerves scattered around the animal

nervous systems in bilaterally symmetrical animals

central nervous system; neural mass: ganglion

Asexual Reproduciton

no production and fusion of haploid cells → budding or fragmentation