BIO422 - ARCHITECTURAL PATTERNS & TAXONOMY

How are animals arranged according to organismal complexity?

Hierarchical manner, increasing complexity

Describe the protoplasmic level

Characterizes unicellular organisms wherein all life functions are within a single cell

Describe the organelles in a protoplasmic organism

Protoplasm is differentiated into organelles with specialized functions

Describe the cellular level grade of organization

Organisms are an aggregation of cells with different functions where division of labor is apparent

Describe the cell-tissue grade of organization

Organisms where clusters of similar cells form tissues to perform the same common function

Describe the tissue-organ grade level of organization

Organisms where aggregation of more than one type of tissue form organs with a more specialized function

Differentiate the parenchyma and stroma

Parenchyma - chief cells that perform main role
Stroma - supporting cells

Describe the organ system level of organization

System where group of organs work together to perform some function producing the highest level of organization.

what are eumetazoans?

organisms at or beyond cell-tissue level

what are the fluid compartments of eumetazoans?

Intracellular and extracellular space

what is interstitial fluid?

watery substance that directly surrounds cells

Give the basic body systems

1. Integumentary - barrier & protection

2. Skeletal - support structure

3. Muscular - motility & contractability

4. Circular - nutrients & oxygen delivery

5. Respiratory - breathing & gas exchange

6. Digestive - breaking down food & absorbing nutrients

7. Excretory - removal of waste

8. Nervous - controlling body function

9. Endocrine - hormone and body process regulation

10. Reproductive - offspring generation

11. Immune - defend against infection

what is body symmetry?

The state of balanced proportions or corresponding size and shape of different sides

Describe spherical body symmetry

If a plane passes through in the middle, two identical halves will be produced. It occurs in unicellular organisms

Describe radial symmetry

Two or more planes passing through the longitudinal axis create similar halves. These animals are tubular/vase shaped, and sessile

what is an advantage of radial symmetry?

Organism is able to interact with environment from all directions

Differentiate the two ends of an organism exhibiting radial symmetry

Oral surface - mouth

Aboral surface - where basal attachment disc is

Describe biradial symmetry

Variant of radial symmetry where an organism can only produce mirrored halves when two planes pass, a combination of radial and bilateral symmetry

Describe bilateral symmetry

Symmetry where a plane passing through the sagittal axis divide the body into left and right halves

Benefits of bilateral symmetry

Cephalization or the concentration of organs in the head region making them able to sense and respond to environment efficiently

Two animals referred to as radiata, primary radial as adults

Cnidara and Ctenophora

Describe the body plan of echinoderm

Primarily bilateral but become secondary radial as adults

Sagittal Plane?

Divides left and right halves

Transverse Plane?

Divides anterior and posterior (front and back)

Frontal Plane?

Divides dorsal and ventral (upper and lower halves)

Differentiate Medial vs lateral

Medial - midline; lateral - sides

Differentiate Distal vs proximal

Distal - away from the middle; Proximal - towards the middle

Differentiate pectoral vs pelvic

Pectoral - chest region; Pelvic - hip region

what are body cavities?

Internal spaces that can only be defined by their boundaries

Describe a blastula

Body cavity that a zygote transforms into after undergoing cleavage

Describe gastrulation

Formation of germ layers

whahat is the gastrocoel?

also called archenteron, the invagination formed during gastrulation

what is the blastopore?

The opening of the gastrocoel, becomes either mouth or anus

what is the endoderm?

It is the gut cavity lining

what is the ectoderm?

Lining of blastocoel

Define diploblastic

Animals that only develop from two germ layers: endoderm and ectoderm

Define triploblastic

Animals that develop from three layers: endoderm, ectoderm, mesoderm

How is the mesoderm formed?

endodermal cells from near blastopore ingress to blastocoel forming early mesodermal cells

Describe acoelomate formation

Mesodermal cells completely fill blastocoel

Only have gut cavity and region is filled with parenchyma

Describe pseudocoelomate formation

Mesodermal cells line the outer edge of blastocoel only

A gut cavity and pseudocoelom is made

Describe coelomate formation

Mesodermal cells create a cavity by lining the outer edge of blastocoel and the gut cavity

Forms gut cavity and true coelom

Describe schizocoelous formation

Early mesodermal cells fill blastocoel forming a solid band of tissue around gut cavity

Describe enterocoelous formation

Cells from the gut cavity protrude and eventually pinch off, expanding then forming a mesodermal cavity

what is the peritoneum?

Thin cell membrane present in eucoelomate derived from the mesoderm

what are mesodermal mesenteries?

These suspend organs in the coelom

Describe the pathway of developmental origin that occurs in lophotrochozoan protostomes

Lophotrochozoan Protostomes:

Cleavage: Spiral

Openings: Blastopore is mouth, second is anus

Development: Mosaic

Body Plan: Schizocoelous

Describe the pathway of developmental origin that occurs in deuterostomes

Deuterostomes

Cleavage: Radial

Opening: Blastopore is anus, second is mouth

Development: Regulative

Body Plan: Enterocoelous

what is a blind or incomplete gut?

Only one opening for entering and excretion

what is a complete gut?

Food enters one way flow of mouth to anus

Describe segmentation or metamerism

principle where animals exhibit serial repetition of similar body segments along longitudinal axis

what do you call each repeated segment?

Metamere or somite

Purpose of segmentation

Permits greater body mobility & complexity of structure and function

what are extracellular structural elements?

supportive material of the organism, including connective tissue, cartilage, bone, and cuticle

what is the study of tissues?

histology/microanatomy

what is the epithelium?

sheet of cells that cover a surface

it forms a protective layer inside & outside the body

where large variety of transport molecules occur

produce mucus, hormones, enzymes

Describe the simple squamous epithelium

made of flattened cells that compose the lining of areas where diffusion and transport of gases and molecules occur

Describe the simple cuboidal epithelium

short, boxlike cells that line areas that perform secretory or absorptive functions

Describe simple columnar epithelium

taller, cuboidal cells with elongated nuclei and microvilli which occurs on highly absorptive sufaces

Stratified squamous epithelium

consists of two or more layers of cells adapted to withstand mild mechanical abrasion and distortion

what are desmosomes

Found between stratified squamous epithelium cells that resist epithelial cell distortion

what is transitional epithelium?

type of stratified epithelium specialized to accommodate great stretching

what are hemidesmosomes?

Attaches epithelial cells to underlying connective tissue

what are connective tissues?

Tissues composed of few cells, many extracellular fibers, and a ground substance that serve various binding and supportive functions.

Describe loose connective tissue

also called areolar connective tissues, it serves as the packing material of the body that supports blood vessels, nerves, and organs

Give the fiber types of loose connective tissue

Collagen fibers, thin elastic fibers formed of elastin

Describe dense connective tissues

forms tendons, ligaments, fasciae arranged as sheets or bands surrounding skeletal muscle

what is collagen?

Composes many of the fibers of connective tissue, it is a protein of great tensile strength

This is composed of distinctive cells in a fluid ground substance termed plasma in blood

Blood lymps/vascular tissue

what is cartilage?

semirigid form of connective tissue composed of chondrocytes (firm matrix cells) located in lacunae and collagen/elastic fibers

It is the strongest vertebrate connective tissue, composed of a calcified matrix containing salts organized around collagen fibers

Bone

what are osteocytes?

small pockets of lacunae within the matrix that contain bone cells

what are canaliculi?

Tiny network of channels in the bone where osteocytes run through

It appears transversely striped, with alternating dark and light bands

Striated muscle

Describe the skeletal muscle

Composed of extremely long, cylindrical fibers which are multinucleate cells that span the whole muscle

Describe vertebrate skeletal muscle

Voluntary muscle that contracts when stimulated by nerves controlled by CNS

Describe invertebrate skeletal muscle

May be controlled by both stimulatory and inhibitory nerve activity

Describe cardiac muscle tissue

involuntary, present in the vertebrate heart, branching network of fibers with uninucleate individual cells that are interconnected by intercalated discs

what are obliquely striated muscle?

present in invertebrates, diagonally arranged muscle fibers with a slower contraction rate compared with other striated muscle

Describe smooth muscle in vertebrates vs invertebrates

Vertebrates: involuntary muscle that surrounds blood vessels and internal organs

Invertebrates: serves as body wall musculature surrounding ducts and sphincters

It is the cytoplasm of muscle fibers

Sarcoplasm

These are the contractile proteins within the fiber

Myofibrils

Two basic types of cells in nervous tissue and their function

Neurons: basic functional unit of nervous systems

Neuroglia: Nonneuronal cell type that insulate neuron membranes

what is the soma?

nucleated cell body

what are dendrites?

receive electrical signals from receptors or other nerve cells

what is an axon?

carries signals from cell body to synaptic terminals

what is the myelin sheath?

Increases speed of electrical signal transmission

what are nodes of ranvier?

interruptions in the schwann cell insulation that allow action to leap from node to node

what is taxonomy?

Formal system for naming and grouping species

what is systematics?

Classification system of organisms not only based on common features but also evolutionary relationship

who was the first person to group organisms according to their structural similarities?

Aristotle

He was a Swedish botanist who produced an extensive system of taxonomy for both plants and animals using morphology to arrange specimens in collections.

Carolus Linnaeus

what is a taxon?

grouping of organisms (plural: taxa)

what are biologist’s criteria on identifying species?

Common descent, smallest distinct groupings, reproductive community, geographic range, evolutionary duration

what is cosmopolitan?

species having very large geographic ranges/worldwide distributions

what is meant by the term endemic? (related to revolutionary relationship)

species with very restricted geographic distributions

what is the binomial nomenclature?

Two part naming system, genus + species epithet

List in order from most inclusive to least inclusive, the principal categories in Linnaean classification

Kingdom

Phylum

Class

Order

Family

Genus
Species

Differentiate holotype and paratype

Holotype: single specimen that bears the name of a recognized species

Paratype: additional specimens that accompany holotype in forming type series

who formulated the biological species concept?

Theodore Dobzhansky and Ernst Mayr

Differentiate typological species concept and biological species concept

Typological species concept: species were classified based on their fixed, essential features that was a divinely created pattern or archetype

Biological species concept: species is a reproductive community having common reproductive compatibility