Lab Practical 3: Simplified - Embryology, Porifera, Cnidaria, Arthropods PDF

Embryology Sea star development: identify cleavage, blastula, gastrula and any important structures associated with the stages Zygote Cleavage: series o...

Embryology Sea star development: identify cleavage, blastula, gastrula and any important structures associated with the stages Zygote Cleavage: series of mitotic cell divisions with no cell growth - After three divisions → 8-cell stage - Cells continue to divide and/ or rearrange Blastula: - formed by blastulation - Migration of cells → hollow ball -Blastocoel (know where it is): internal cavity  Gastrula Formed by gastrulation - Invagination (folding inward) forms blastopore and archenteron (embryonic gut) - Sets up formation of outer (ectoderm) and inner (endoderm) germ layers - Organogenesis gives rise to tissues, organs, organ systems (not on study guide but just in case) (not on study guide but just in case) Frog embryonic development slides: identify cleavage, blastula, gastrula and any important structures associated with the stages Cleavage: series of mitotic cell divisions with no cell growth - After three divisions → 8-cell stage - Cells continue to divide and/ or rearran early late Blastula -center cavity = blastocoel -see starfish for more info Gastrula - see sea star for more info  Porifera & Cnidaria Parazoa - Porifera: Choanocytes: - pulls water through the sponge to trap and ingest food Porocytes: - controls water flow through the ostia Spongocoel: - central cavity Osculum: - opening for water expulsion Gemmules (freshwater sponges): - stress resistant aggregates of amoebocytes - released as means of asexual reproduction - in favorable conditions, amoebocytes in gemmule can grow into a mature organism Spicules: - supportive spikes of silica Spongin fibers: - reinforce cell wall - proteinaceous Eumetazoa - Cnidaria: Hydra - characteristics & identification: - organized into specialized tissues - interior gut cavity specialized for extracellular digestion - radially symmetrical - epidermis includes stinging cells (cnidocytes) & each cnidocyte can discharge a harpoon like nematocyst - cnidocytes scattered on body wall & dense on tentacles  Obelia - characteristics & identification - colonial polyps & free swimming medusae - appear plant like and branch from a tube - polyps are obelia are polymorphic bc some are specialized feeding polyps called gastrozooids; others are reproductive polyps called gonozooids hydroid medusae Porifera & Cnidaria Lophotrochozoa - Platyhelminthes (flatworms): Three body plans for bilaterally symmetrical animals a.) acoelomates → no body cavity Includes flatworms b.) pseudocoelomates → develop a body cavity between mesoderm & endoderm Includes nematodes c.) coelomates → have a body cavity bounded by mesoderm Includes mollusks, annelids, & more advanced phyla Be able to identify (highlighted) Auricles Eyespots Pharynx Mouth Cross section of planarian taken through pharynx region Fasciola - don’t need to know specific structures just be able to identify Fasciola Lophotrochozoa - Mollusca: Radula: know function & which groups its found in Function: rasp-like organ with chitinous teeth to scrape algae off rocks Groups: - Polyplacophora - Gastropoda - Cephalopoda Class Polyplacophora "Many plates” Chitons Reduced cephalization Radula present Chiton- Polyplacophora - Be able to identify foot Class Gastropoda “Stomach foot” Snails, slugs, conchs, nudibranchs Most diverse group = 80% of molluscs Respiratory: aquatic species = gills; terrestrial = lungs Radula present Snail - Gastropoda Identify - Foot - Mantel - Shell Class Bivalvia “Two leaves of a door” Clams, oysters, scallops Reduced cephalization Lack radula Clam - Bivalvia Identify anatomical structures and their function - Mantle - Shell - Foot - Gills - Labial palps - Mouth - Stomach - Anus Clam (Anodonta) anatomy. The left valve and mantle are removed. During filter feeding, water enters the mantle cavity posteriorly and is drawn forward by ciliary action to the gills and palps. As water enters the tiny openings of the gills, food particles are filtered out and caught in strings of mucus carried by cilia to the palps and directed to the mouth. Food particles are moved toward the mouth by cilia on the gills. Sand and debris drop into the mantle cavity and are removed by cilia. Class Cephalopoda “Head foot” Octopus, squid, nautilus Most unique group of molluscs Closed circulatory system: hearts and vessels “Intelligent” group of invertebrates Carnivorous predators with beak-like jaws and radula Squid & octopi specimens - Cephalopoda  Annelids & Nematodes Lophotrochozoa - Annelida (segmented worms): Nereis - specimen Earthworm - movement: Identify structures and their function: - Mouth - to take in soil and other organic matter that they use as food - Anus - the opening through which undigested food particles, known as worm castings, are expelled from the body - Clitellum - regulating reproduction, regeneration, stem cells, organogenesis, aging, stress response, and autotomy - Pharynx - helps the worm ingest food and soil by creating suction - Part of digestive system - Esophagus - transports food from the pharynx to the crop - Crop - a temporary storage area for ingested food - Gizzard - grinds food into smaller pieces to help with digestion - Intestine - break down food into usable chemicals that are then absorbed into the earthworm's bloodstream Cross section longitudinal & circular muscles Lumbricus c.s Lumbricus (earthworm) setae Ecdysozoa - Nematoda (roundworms):  Ascaris Comparison of all worm types  Feature Annelids (Earth/ Nematodes Platyhelminthes segmented worms) (Roundworms) (Flatworms) Coelom Eucoloem Pseudocoelom Acoelom Types of muscles Circular & Longitudinal Circular, longitudinal, longitudinal diagonal Digestive system Complete Complete Incomplete - GVC Segmentation Only ones that are None None segmented Body movement Inching/ pulling, Whip-like Undulating waves Arthropods Ecdysozoa - Arthropods: Subphylum Chelicerata Spiders, horseshoe crabs Chelicerae – claw-like or fang-like mouth parts Horseshoe crabs - Chelicerata Identify structures: - Telson - Abdomen - Carapace Subphylum Crustacea “Shelled ones” Mostly aquatic Respiration – gills Crayfish - Crustacea Structures & function: - Carapace - Shield, protects the crayfish's vital organs - Cheliped - Appendage used for feeding - Antenna - touch, taste, and smell - Cephalothorax - Body segment consisting of fused head & thoracic segments - Abdomen Subphylum Myriapoda “Many legs” Chilopoda – centipedes (1 set of legs per segment) ○ carnivores Diplopoda – millipedes (2 sets of legs per segment) ○ herbivores Centipede - Myriapoda Millipede - Myriapoda Subphylum Hexapoda "Six legs” – insects; largest group of arthropods Respiration – openings (spiracles) in exoskeleton lead to tubes (tracheae) that branch throughout the body Insect - Hexapoda Most direct & efficient respiratory Respiration system Spiracles → trachea tubes → diffuses into tissues ○ Do not breathe through the mouth ○ Do not have lungs Independent of circulatory system ○ Hemolymph does not carry oxygen Limits body size Grasshopper - Hexapoda Identify & know function: - Head - hard capsule that contains large muscles, which operate the chewing mouthparts, and the brain and subesophageal ganglion, which serve as the main centers of the nervous system - Thorax (locomotion center) - primary center for movement and is responsible for the grasshopper's ability to walk, jump, and fly - Abdomen - Body segment that contains the grasshopper's digestive and reproductive organs - Tympanum (eardrum) - detects vibrations and allows the insect to hear sounds - Spiracles - tiny breathing pores, acting as openings on the body that allow air to enter the tracheal system - Allows effective delivery of respiratory gases - Ovipositor - two pairs of shovel-shaped valves that are used to dig a deep chamber in the ground for egg burial, to manipulate the eggs, and to assist in capping the egg-pod with froth - Tracheal tubes - part of their respiratory system, and their primary function is to deliver oxygen to the grasshopper's cells - Malpighian tubule - main excretory organs in most insects - production of primary urine and osmoregulation, selectively reabsorbing water, ions, and solutes Metamorphosis - incomplete Metamorphosis - complete young resemble small adult organism looks different in each ○ Egg→nymph→adult stage ○ Egg→larva→pupa →adult  Echinodermata & chordata Lab specimen - echinoderms Lab specimen - echinoderms - Sea urchin - Seastar  Starfish development composite w.m Starfish early bipinnaria Starfish pedicellariae - Seacucumber Starfish ray (arms) Subphylum Urochordates Larvae possess all chordate features Adults have pharyngeal slits  Tunicates – sea squirts Lab specimen - Urochordates Tunicate larva - Tunicates Subphylum Cephalochordata Possess all chordate characteristics as adults Lancelets: small filter feeders that bury in the mud Lab specimen - Cephalochordata Lab specimen - Cephalochordata - Ammocoete larvae - Lancet Jawless fish - Hagfish: poorly developed cranium and notochord does not develop into vertebral column Transitional group between chordates and vertebrates Lack jaws and paired lateral appendages (fins) Have gills Scavengers and parasites Jawless fish - Lamprey: possess a skull and simple vertebral column Lack jaws and paired fins Parasitic Infraphylum Gnathostomes – Jawed Fishes Jaw: hinged structure attached to cranium that allows for grasping and tearing of food Derived from first set of gill arches Two sets of paired fins Gnathostomes - Chondrichthyes: cartilaginous fish Gnathostomes- Osteichthyes: bony fish - Actinopterygii: ray-finned fish - Sarcopterygii: lobe-finned fish shark & ray specimen Actinopterygii - ray-finned fish anatomy Know featured & functions: - Operculum - bony flap that protects the gills from harm - Swim bladder - gas-filled organ that helps ray-finned fish maintain buoyancy in water - Liver - processing, and storage of nutrients, the synthesis of enzymes and other cofactors, bile formation and excretion, and the metabolism of xenobiotic compounds - Stomach - stores, mixes, and digests food through mechanical and chemical actions - Intestine - Digestion & absorption of nutrients - Gills - breathe underwater Amphibians Descended from lobe-finned fishes First land vertebrates ○ Terrestrial, but require water for development of eggs and  larvae Respiration: gills in larvae, lungs in adults (mostly), permeable skin for cutaneous respiration 3-chambered heart with double circulation of blood Order Urodela (tailed): salamanders ○ Some are lungless Order Anura (tail-less): frogs Order Apoda (legless): caecilians ○ Single lung Lab specimen - Amphibians - newts, frogs & toads Amniotes - Reptiles Turtle, lizard. Snake, specimen Tetrapods Calcareous or leathery amniotic eggs laid on land Scaly, waterproof skin reduces water loss  ○ Loss of cutaneous respiration 🡪 evolution of more advanced lungs and ribs for more efficient respiration Ectotherms (except birds) = less energy required 1 occipital condyle 3-chambered heart - except crocodiles Aves (Birds): characteristics of this group & Endothermic with high body adaptations for flight temperature High metabolic rate Adaptations for flight ○ Feathers: modified scales; aid in insulation ○ Hollow bones ○ Keel-shaped sternum with heavy breast musculature ○ Efficient respiration ○ Lack urinary bladder ○ Reduction in reproductive organs of females Bird - anatomy Structures to identify & know function of: - Lung - exchange oxygen and carbon dioxide between the blood and the air - Crop - stores food temporarily and starts the digestion process before it enters the stomach - Gizzard - grind food and aid digestion - Cloaca - acts as a waste elimination chamber for both urine and feces Mammals Single jaw bone: dentary; other bones evolved into the malleus & the incus in the middle ear Most have highly differentiated teeth replaced once in their lifetime Endothermic Hair Secretory glands in the skin: mammary → milk Most have non-nucleated RBCs Four chambered heart Diaphragm Left aortic arch Two occipital condyles on the skull Most have seven cervical vertebrae  Lab specimen - Eutherians Mouse & bat Vertebrate tissue Epithelial: cover & protect lines cavities, open spaces, and surfaces Squamous Slightly irregular, flat, small central nucleus Simple: facilitate diffusion Stratified: protection Location: - simple: lung alveoli, capillaries; - stratified: skin, mouth, vagina Stratified squamous epithelium on hairy lab slide mammal slide Cuboidal Cube shaped with a single, central nucleus Simple Glandular tissues, walls and ducts of tubules Location: glands, renal tubules  Kidney cuboidal epithelium slide Columnar Taller than wide Simple vs. pseudostratified lab slide Connective: binding, support, transport; cells within a matrix Connect different tissues and/ or support body structure (except blood) Matrix of cells embedded in non-living substance ○ Fibroblast cells: motile, carry out mitosis, synthesizes fibers of connective tissue ○ Ground substance: organic substance (proteins) plus inorganic substance (mineral or water) Areolar/ loose Surrounds blood vessels and body organs for stability Location: - Around blood vessels; anchors epithelia lab slide Adipose Lacks fibroblasts and a matrix, few fibers Adipocytes store triglycerides Insulation and cushioning for organs Location: - adipose (fat) Adipose tissue osmium Adipose tissue mammal  Adipose tissue OsO4 sec Bone: Osteoblasts: make bone for growth and Remodeling ○ Deposit bone material into matrix – matrix surrounds cell – live as osteocytes Osteocytes: mature cells that maintain bone Osteoclasts: break down bone for remodeling Compact bone: dense; strength Spongy bone: porous; shock absorption Location: vertebrate skeletons bone-ground human bone dry ground bone Blood: Plasma: fluid matrix RBCs – erythrocytes Deliver oxygen to tissues WBCs – leukocytes Immune response Location: - Blood human blood frog blood Cartilage: Large amount of matrix and variable amounts of fibers Location: shark skeleton, fetal bones, human ears, intervertebral discs lab slide  Fibrous/ dense: Collagen fibers, few cells or matrix material Location: irregular: skin; regular: tendons, ligaments Muscular: specialized for contraction, generate movement *Don’t need to be able to identify just know the different types* Smooth: involuntary, unstriated Skeletal: voluntary, striated, multinucleated Cardiac: involuntary, striated, intercalated discs Nervous: reception of stimuli & conduction of nerve impulses Neurons generate and transmit electrical impulses lab slide