Final exam pt 1

Kingdom Animalia - general characteristics, invertebrates vs. vertebrates, Multicellularity, choanoflagellates; sac vs. tube within a tube

  • Multicellular, with a focus of GKPID

    • GKpid is a protein that helps with spindle orientation, found in all animals

  • They are heterotrophic, and acquire this energy through a diverse set of modes

  • Nervous tissue is present and is used for rapid response

  • Muscle tissues is used for movement

  • Sexual reproduction

    • Small mobile sperm, larger egg

    • Diploid from a blastula

    • Metamorphosis

  • Have an extracellular matrix of collagen

  • Have specific clusters of Hox genes

  • Similar rRNA in all

  • All have cell junctions of anchoring, tight, or gap

Invertebrates were the first of the animals, and after the cambrian explosion the first vertebrates evolved, these were the fishes


97-99% of all animals are invertebrates

  • Heterogeneous assemblage of groups

  • No single positive character in common

Vertebrates, 1% of animals

1 phylum, chordata

  • Sac

    • With this body plan there is only one opening to the gut

  • Tube within a tube

    • With this body plan there are two openings to the gut


Classification: Diploblastic, Triploblastic, endoderm, mesoderm, ectoderm

  • Triploblastic means of 3 layers, meso, ecto, and endoderm

  • The only diploblasts are cnidaria, and ctenophora, only have ectoderm and endoderm

  • Endoderm is the innermost layer, forms the digestive and respiratory systems

  • Mesoderm is the intermediate layer that forms the axial skeleton, some muscles, and blood cells

  • Ectoderm is the outermost layer, forms the nervous system



Coelom, importance of coelom; Acoelomate, Pseudocoelomate, Eucoelomate

  • Coelom: Fluid filled space around the gut in which organs are suspended

  • Acoelomate: no coelom, this makes them triploblastic as their organs develop from the endoderm, the mesoderm, and the ectoderm

  • Blastocoelomate/Pseudocoelomate: have a body cavity, however it is not solely lined with mesoderm, also triploblastic, endoderm, mesoderm, and ectoderm

  • Acoelomate, has a true coelom, also triploblastic, ectoderm, endoderm, and mesoderm


Symmetry: radial, bilateral; cephalization; incomplete vs. complete digestive system

  • Radial symmetry: Two identical halves, think about a squid

  • Bilateral symmetry: Definite right and left halves, 

Protostome, Deuterostome, Segmentation (metamerism)

  • Protostome: the 1st embryonic opening becomes the mouth, (most of bilateria: annelids, arthropods, molluscs)

    • Determinate cleavage

    • Mosaic embryo

    • Schizocoely

    • Blastopore becomes mouth

  • Deuterostome: 2nd embryonic opening becomes the mouth (echinoderms, chordates)

    • Indeterminate cleavage

    • Regulative embryo

    • Enterocoely

    • Blastopore becomes anus

  • Segmentation allows for specialization of body regions, occurs in annelid worms, arthropods, and chordates

Animal Phylogenetic Tree

Porifera - Sponges, cellular level of organization, ostia, oscula, spicules, spongin, choanocytes, pinacocytes, archaeocytes, mesohyl, spongocoel, sessile filter feeder, sexual and asexual reproduction, gemmules

  • Only level on animal to have cellular organization (parazoa)

  • Saclike bodies perforated by many pores (Ostia)

  • Lowest level of organization, organized at the cellular level

  • In basic term, an aggregation of cells, groups with specialized functions

  • Division of labor

  • Beating of flagella from the choanocytes produces water currents that flow through pores into central cavity and out the osculum

  • Sessile filter feeders

  • Asexual reproduction by fragmentation or budding

Asconoid, Syconoid, Leuconoid,

V=1/A

  • Asconoid 

    • Small tub-shaped flagellated spongocoel

    • Bath sponge

  • Syconoid 

    • Tubular body

    • Flagellated canals

    • Glass sponge

  • Leuconoid

    • Most complex, largest 

    • Large colonial masses

    • Flagellated chambers

    • Barrel spong

Cnidaria - radial symmetry, diploblastic, tissue level of organization

  • Cell-tissue level of organization

  • Groups of similar cells arranged in definite patterns or layers with a common function=tissue

  • Many scattered cells are present

  • These include epithelial tissue, connective tissue, muscular tissue, and nervous tissue

  • They are diploblastic

  • Have radial symmetry

  • Polyp and medusa body forms

  • Specialized stinging cells (cnidocytes)

  • Fluid filled capsule (cnidae), with nematocyst

  • Two layered body sac

    • Outer layer- protective epidermis, mesogela

    • Inner layer- gastrovascular cavity

  • Nerve net found throughout body



polymorphism (dimorphism), polyp, medusa, gastrovascular cavity, tentacles, mouth, cnidocytes with nematocysts, nerve net, planula larva, mesoglea, epidermis, gastrodermis

  • Dimorphic, can either be polyp or medusa

  • Have a gastrovascular cavity right next to mouth surrounded by mesoderm

  • Both have tentacles for movement

  • Mouth for digestion

  • Cnidocytes stinging cells, these are called nematocysts

  • Simplest form of nervous system is nerve net, with all connected and sending signals everywhere 

  • Epidermis is the outermost layer, contains the cnidocyte

    • Has epitheliomuscular cells

  • Gastrodermis

    • Inner layer of epidermis

    • Connects to gastrovascular cavity

    • Gland cells, sensory cells, and nutritive muscular cells

  • Mesoglea layer between gastrodermis and the epidermis


Hydrozoan life cycle (Obelia) – gastrozooid, gonozooid,

  • Exist in marine and freshwater

  • A colony of polyp enclosed by a hard chitinous covering

    • Feeding polyps these are the gastrozooid

      • These extend beyond the covering

      • Have nematocyst-bearing tentacles

    • Reproductive polyps these are the gonozooid

      • They do the budding of new polyps

  • Also has sexual reproduction stage (medusae)

Scyphozoa (Jelly) - life cycle, scyphistoma, strobilation, ephyra, Cubozoa

  • Medusa; thick mesoglea

  • FLoat in open sea

  • Manubrium with oral lobes

  • Stomach with pouches

  • Sense organs ar the rhopalium

    • (statocyst + ocelli)

  • Separate sexes

  • The Cubozoa, are box jellyfish, these are deadly

Life cycle 

  • Start as sperm and egg, fertilized into zygote, then planula

  • Form Scyphistoma, undergo strobilation, (asexual budding)

  • Becom Ephyra which is the developed form, then repeat the cycle

  • Are dimorphic

Anthozoa (Sea anemones) - septa, siphonoglyph, pedal laceration

  • Anthozoa, these are the flowering animals

  • Polyps, no medusa stage

  • Sea anemones, hard corals, sea fans

  • Large gastrovascular cavity with septa

  • Ciliated groove, siphonoglyph

  • Circular and longitudinal muscles

  • Attached by pedal disk

    • Pedal laceration

  • Potent nematocysts/acontia

  • Coral reefs- Hermatypic corals 

    • Calcareous cups secreted by polyps, zooxanthellae

Septa (Mesenteries)

  • Sea anemones have a central gastrovascular cavity divided into compartments by vertical partitions called septa or mesenteries.

  • Septa increase the surface area for digestion and nutrient absorption.

  • These structures can be complete (extending fully from the body wall to the pharynx) or incomplete.

  • Some septa bear specialized stinging cells (cnidocytes) for prey capture and defense.

  • Siphonoglyph

The siphonoglyph 

  • ciliated groove found at the pharyngeal wall near the mouth opening.

  • It creates water currents, facilitating gas exchange, excretion, and maintaining hydrostatic pressure for structural support.

  • This feature also helps prevent clogging of the gastrovascular cavity


Corals - zooxanthellae, calcareous cup, mutualism, reefs;

  • Zooxanthellae is where photosynthesis occurs in the coral

  • Need CO2, H2O and Nutrients, forms organic matter an O2

  • This is also how they do respiration

  • Calcareous cup: This refers to the calcium carbonate skeleton secreted by coral polyps, which forms the structural foundation of coral reefs. These skeletons provide the rigid framework that supports reef ecosystems.

  • Mutualism: Coral reefs thrive due to a mutualistic relationship between coral polyps and zooxanthellae (photosynthetic algae). The algae live within the coral tissue, providing nutrients through photosynthesis while benefiting from the protection and waste products of the coral.

  • Reefs: Coral reefs are diverse underwater ecosystems built primarily by corals that secrete calcareous skeletons. They support marine biodiversity, protect shorelines, and provide resources for humans.

Ocean Acidification

  • Due to pollution and increase of Bicarbonate, an acid, is being formed in the ocean leading to thin shells in animals and dead coral

  • By lowering CO2 levels the ocean will then form more, Carbonate and eventually more Calcium carbonate, which is basic and will restore the ocean to a healthy pH