bio lab 4 week 11 Flashcards
What does phylum chordata include
Invertebrates (amphioxus) and vertebrates
What are chordates characterized by
The presence of Notochord (a supporting rod) Hollow dorsal nerve cord Pharyngeal gill slits Post-anal tail during at least one stage in their life cycle
Name animals in phylum echinodermata
Starfish (sea stars)
Sea urchins
Sea cucumbers
Sea lilies
Describe symmetry of echinoderms
Adults have radial symmetry
Immature larvae has bilateral symmetry
Indicates that ancestors of echinoderms had bilateral symmetry
How are echinoderms related to chordates
Striking similarities in embryological development (deuterostome)
Describe skeleton of echinoderms
Internal skeleton consisting of numerous calcareous plates embedded in body wall
Plates have bumps or spines which protrude from the surface of the animal
Describe unique water vascular system of echinoderms
Used for locomotion and grabbing food items
Echinoderm can hold onto a surface by applying suction with tube feet of its water vascular system
It can open the shell of a clam to get at the animal inside
List and describe external anatomy of a star fish (6)
Rays = arms with a light receptor at the tip
Mouth = located in the center of the oral side (underside)
Aboral side = side opposite the mouth
Madreporite = small stony plate that is the entrance to the water vascular system
Dermal gills = finger-like sacs used for gas exchange
Tube feet = found in the ambulacral groove on the oral side
Describe phylum porifera
Sponges live in shallow warm sea water
Mainly asymmetric body symmetry, some have radial body symmetry
No tissues or organs
What are sponges made up of
Made up of several different types of cells living together with a common skeleton composed of crystalline spicules or proteinaceous fibres or both
Describe 3 layers of body of sponge
Outer layer of flattened epidermal cells
Middle gelatinous layer with amoeboid cells (secrete the skeleton)
Inner layer of flagellated cells called choanocytes (collar cells)
What does flagella do in sponges
Flagella create a water current that carries food particles through pores of the sponge (filter feeding)
Describe intracellular digestion of sponges
Food particles are phagocytosed by choanocytes and amoeboid cells
Describe the tissues evolved in phylum cnidaria
Ectoderm = epidermis
Endoderm = gastrodermis
Mesoglea = gelatinous layer sandwiched between the 2 layers
Cnidaria are diploblastic
Name types of cells found in cnidaria
Nerve cells arranged in a nerve net
Gland cells
Cells that contract
Stinging cells called cnidocytes
What are cnidocytes
Cnidocytes are specialized epidermal cells on tentacles of cnidarians
Have small barbs or threads that carry an irritating and stinging chemical coiled into a capsule called a nematocysts
(Nematocysts discharge the threads in response to a chemical stimulus or touch
Used to sting and capture prey)
What do cnidarians have
Radial body symmetry Gastrovascular cavity (1 opening, 2 way)
Name the two forms of cnidaria
Polyp
Medusa
Do all cnidarians exhibit only one form their whole lives
Some only exhibit one body type their whole life cycle
Some can alternate between forms = polymorphism
Name organisms phylum cnidaria contains
Hydroids
Jellyfishes
Sea anemones
Corals
Describe hydra (phylum cnidaria)
Freshwater hydroid that only exhibits one body form throughout its life cycle
Describe obelia (phylum cnidaria)
Either reproductive polyps (produce medusas asexually, medusas reproduce sexually) or feeding polyps (obtain food)
Describe phylum platyhelminthes
Bilateral symmetry
Acoelomate
Triploblastic (endoderm, mesoderm, ectoderm)
Cephalization (sensory organs concentrated in head region)
Have gastrovascular cavity (EXCEPT tapeworms)
What do flatworms have
Some flatworms have primitive nervous and muscular system
Well developed reproductive systems
Describe 3 groups of phylum platyhelminthes
Planarians which are free-living
Flukes are parasitic
Tapeworms are parasitic
Describe planaria (phylum platyhelminthes)
Free living not parasitic, have eye spots, highly branched gastrovascular cavity and pharynx
Describe flukes (phylum platyhelminthes)
Parasitic flatworms that live in the digestive system of the host, have muscular suckers used to attach to the host and reproductive organs (takes up most of the body)
Describe tapeworms (phylum platyhelminthes)
Ribbon like parasitic worms that live in digestive tract of host
Scolex = head segment that has suckers and hooks to attach to the host
Proglottids: rest of the segments that contain a complete set of reproductive organs. The eggs of one segment are fertilized by the sperm from the segment before it
Describe phylum nematoda
Triploblastic
Pseudocoelom = body cavity is not completely derived from mesoderm
Complete digestive tract (2 openings, 1 way, mouth to anus)
Tube within a tube body plan
What are annelids (phylum annelida)
Worms that have bodies which are divided into many segments
Segments are separated from each other by transverse partitions (septa)
Segments are similar to one another internally and externally
Tube within a tube body plan
Coelom
Describe circulatory system of annelids
Closed circulatory system with 5 pairs of hearts
Hearts are enlarged portions of the dorsal vessel that contract to pump blood throughout body of the worm
Describe gas exchange for annelids
Occurs across the body surface
Name 3 groups of phylum annelida
Leeches (freshwater)
Earthworms (soil)
Sandworms (marine)
Describe earthworms (phylum annelida)
Have a clitellum and a segmentation of the body
Describe leeches (phylum annelida)
Have suckers used to suck blood and a segmentation of the body
Describe sandworms (phylum annelida)
Have fleshy extensions called parapodia along the sides of the tapeworm’s body (used as external gills for gas exchange and movement)
Describe phylum mollusca
Second largest phylum in animal kingdom
Mainly marine molluscs but terrestrial and freshwater forms also exist
Bilateral symmetry
Describe body plan of molluscs
Muscular ventral foot
Fleshy dorsal visceral mass that contains digestive tract, heart, excretory system and other internal organs
Mantle that usually secretes a protective shell
Name 3 major groups of phylum mollusca
Snails
Bivalves = clams and oysters
Cephalopods = squids and octopuses
Describe circulatory system of molluscs
Molluscs have an open circulatory system EXCEPT CEPHALOPODS which have a closed circulatory system
Describe clams (phylum mollusca)
Filter feeders = take in water and filter it, small organisms get trapped in the mucus of the gills
Describe squids and octopuses (phylum mollusca)
Very well developed nervous system, reduced internal shell and a closed circulatory system
Describe phylum arthropoda
Exoskeleton = hard, jointed external skeleton
Used for protection and as an attachment point for muscles
Paired appendages that are also jointed attach to the exoskeleton
Name the 3 regions body is divided into for phylum arthropoda
Head
Thorax
Abdomen
In some cases these divisions are modified = head and thorax fuse to form a cephalothorax
Name 11 major groups of phylum arthropoda
Insects Spiders Scorpions Ticks Mites Centipedes Millipedes Crayfish Lobsters Crabs Shrimps
What do insects circulatory system have
Dorsal heart and an open circulatory system
Pumps hemolymph through the vessels into the hemocoel
Body movements bring hemolymph back to heart
Describe gas exchange of arthropods
Uses respiratory devices
Spiracles/tracheal system = insects, millipedes, cnet pieds
Feathery gills = crayfish
Book lungs = spiders and scorpions
Describe crayfish (phylum arthropoda)
Have chelipeds, walking legs, swimmerets, uropods and telson
Sex of speicmen = in males the first 2 pairs of swimmerets are stiffened and project forwards as they help transfer sperm during mating
Describe grasshoppers (phylum arthropoda)
Have spiracles along the side of the abdomen
Spiracles are small openings to the tracheal system, a branched network of tubes that carry oxygen to all the cells in the body
Describe overview of the life of a honey bee
Anatomy and tasks change throughout its life
Average life span = 38 days during summer or longer in overwintering bees
Born blind…
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