Lecture Notes Flashcards

Hydras and Cnidarians

• Hydras attach to rocks via their basal disk.
• Cnidarians exhibit radial symmetry.
• Most Cnidarians go through a planulae larval stage.
• Sessile means attached to one spot, non-mobile.

Cnidarian Anatomy

• Key parts of a cnidarian anatomy include:
  • Tentacles
  • Mouth
  • Gonads
  • Gastrovascular cavity
  • Cnidocytes (stinging cells on tentacles)

Cnidocytes and Nematocysts

• Cnidocytes are stinging cells that hold nematocysts.
• Nematocysts are harpoon-like stingers.
• Function of the basal disk: to stick Cnidarians to surfaces

Corals

• Corals live together as reefs by building on previous generations.

Jellyfish Feeding

• Jellyfish feed by catching and holding food with stinging cells on tentacles and dragging it into their mouth.

Polyp vs. Medusa

• Polyp:
  • Tube-shaped
  • Sessile
• Medusa:
  • Free-floating
  • Umbrella-shaped stage

Cnidarian Reproduction

• Sexual reproduction:
  • Sperm and egg released into water (external fertilization).
• Asexual reproduction:
  • Budding occurs off of polyps to produce medusas.

Nematocyst vs. Cnidocyte

• Nematocyst: Harpoon-like stinger.
• Cnidocyte: Cell that holds the nematocyst.

Cnidarian Classes

• Cnidaria:
  • Hydrozoa
  • Scyphozoa
  • Anthozoa
• Porifera:
  • Asconoid
  • Syconoid
  • Leuconoid

Jellyfish Life Cycle

• Medusa releases sperm and egg.
• Fertilization forms a zygote, then a planulae larva.
• Larva becomes a polyp.
• Polyp forms into a medusa through budding or strobilation.

Body Plans

• Porifera: Asymmetrical
• Cnidaria: Radial symmetry

Sponges

• Sponges circulate water through their body using choanocytes that use flagella to pull water through pores.
• Sponges defend themselves with spicules or chemical/physical defenses from epithelial cells.
• Sponges ingest food by absorbing it through cells.
• Man-of-War is NOT a Jellyfish because it is a colony of hydrazoa and not a true medusa or single organism.

Sponge Anatomy

• Osculum: Large central opening.
• Ostia: Pore cells that cover the body.
• Epithelial cells: Thin, flat outer covering.
• Collar cells (Choanocytes): Flagellum-covered cells that draw water through.
• Amoebocytes: Between cells, carry nutrients.
• Spicules: Support system made of silica or calcium.

Sponge Sexual Reproduction

• Sponges release sperm into the water to drift to other sponges to fertilize eggs.

Sponge Characteristics

• Multicellular
• Sessile
• Eukaryote
• Filter feeder
• Heterotrophic
• Aquatic

Worms and Parasites

• A blood fluke is an endoparasite.
• Hookworms can be contracted by walking barefoot.
• Roundworms and flatworms exhibit bilateral symmetry.

Parasites

• Endoparasite: Lives in inner tissues and intestines.
• Ectoparasite: Lives on outer tissues and skin.
• Earthworms feed by consuming soil, which passes from the crop to the gizzard to the intestine.
• Tapeworms and other parasites obtain nutrients through diffusion through their skin.
• Earthworm cells receive nutrients through a closed circulatory system.
• Endoparasites have a thick outer covering called a tegument to avoid being consumed by their hosts.

Worm Classification

• Platyhelminthes:
  • Planarian
  • Tapeworm
  • Fluke
• Nematoda:
  • Ascaris
  • Trichinella
  • Hookworm
• Annelida:
  • Earthworms
  • Marine worms
  • Leeches

Ascaris Life Cycle

• Host consumes infected food.
• Worms breed in the host's intestine.
• Eggs are excreted in waste.
• The process repeats.
• Most parasitic worm infections are acquired through infected, undercooked meat.

Body Cavities

• Cnidarians: Radial symmetry, no coelom.
• Worms: Bilateral symmetry, pseudocoelom, coelom.
• Earthworm Digestive Tract:
  • Crop: Chemical digestion and storage
  • Gizzard: Physical digestion
  • Intestine: absorbs nutrients
• Segmentation in annelids allows for complex movements, support, and protected body systems, which allow for more complex organs.

Mollusks!

Classes of Mollusks:

• Gastropods: Snails, slugs
• Cephalopods: Squid, octopus
• Bivalvia: Clam, oyster

Mollusks Body Plan:

• Visceral mass
• Foot
• Mantle

Visceral Mass vs. Foot

• Visceral mass = Guts
• Foot = Locomotion

Circulatory systems in Mollusks:

• Open in bivalves and gastropods
• Closed in cephalopods

Mollusks movements:

• moving or sliding using their foot

Characteristics shared by Mollusks and Annelids:

• Coelom

How oysters form pearls:

• Object gets lodged in mantle and Oyster forms protective nacre shell

How do terrestrial snails breathe?

• with a mucus filled mantle cavity

What Closes/Opens a clam?

• Adductor muscles

Mollusk Coelom Advantage?

• Allows for more complex organs

Mollusks foot function?

• Locomotion

Cephalopods foot is?

• divided into numerous appendages

How do squid capture prey?

• Tentacles grab, arms hold

Mollusks chew food with?

• Radula

Squids ink is made of?

• Mucus and pigment

Mollusks water intake/outake organ?

• Incurrent/excurrent siphons

What is the mantle of a mollusk?

• Thick outer tissue layer

Primitive Brain?

• Cerebral Ganglion

Do all mollusks have shells?

• No, they use a Thicker mantle instead

Mollusks Larval Stage?

• Trochophore
• Doesn't resemble adult form

Advantage of true Coelom?

• More advanced organs

What does the nephridium do?

• filter blood and fluids like a simple kidney

Mollusks heart vs others?

• multiple hearts in squid, Single Chambers

Annelid heart vs Mollusks?

• Annelids have pumping vessels not true hearts

Arthropods

Traits of Arthropods:

• Jointed appendages
• Exoskeleton
  *Molting

Classes of Arthropods:

• Centipedes belong to the class Chelipoda (they have jaws)
• Millipedes belong to the class Diplopoda
• Lobster is a member of the subphylum Crustacea

Arthropods examples:

• Bees, spiders, shrimp, mantids and lobsters
• Release hormones with molting

Arachnids

• Predators of insect pests
• Mouthparts modified into fangs/pincers
• Arachnid body = Cephalothorax + abdomen
• Spinnerets direct flow of silk

Insects Facts:

• True Insects have 3 pairs of legs and 3 body sections
• Crustaceans have 2 pairs of antennae

Differences between crustaceans and true insects

• Walking legs, number of antenna, breathing organs, body plan,

Similarities between all arthropods

• exoskeleton, coelom, invertebrate, jointed appendages,

Legs of crustaceans:

• Crabs and crayfish have 5 pairs of walking legs
• Decapoda

Horseshoe crab charateristics:

• 8 legs, no antenna, pedipalps, pincers, tracheae

Insect Breath?

• Terrestrial = tracheae
• Spiders= book lungs

Crustacean excretory gland?

*Green Gland

Spider food?>

• Liquefying and sucking out the liquid using pedipalps

Complete Metamorphosis Stage?

• Egg, larva, pupa, adult

Compound eye?

• Multiple visual units in one structure

Arthropod Swiss army knife Description?

• Multiple body plans and appendages

How Ticks infect?

• Regurgitating blood from previous hosts into the new host

Subphylum Matching:

• Crustacea
  • Shrimp
  • Fiddler Crab
• Uniramia
  • Ladybug Insecta
  • Centipede Chelipoda
  • Millipede Diplopoda
  • Praying Mantis Insecta
• Chelicerata
  • Scorpion
  • Tarantula
  • Deer Tick
  • Mites

Metamorphosis:

*Young insects are born miniature version of the adult, like a praying mantis = incomplete

• Butterflies go through the process of complete metamorphosis.

Fish and Amphibians

• Sharks are in the class Chondrichthyes.
• Bony Fish are in the class Osteichthyes.
• The major respiratory organs of a fish are gills.
• Depending on the type of fish they can use external reproduction if they are bony fish and internal if they are a shark, skate, or ray.
• If they lay eggs they are called Oviparous whereas if they were to internally hatch the eggs before birth they would be referred to as ovoviviparous
• Lampreys and Hagfish are what type of fish (Jawless/ Jawed) also called Agnathans
• They feed by rasping off flesh
• Sharks teeth are considered to be modified Scales
• All fish are vertebrate meaning that they have a hard structure that surrounds their spinal cord.
• Tubules in the kidneys of fish that help with salt and water balancing are called Nephrons
• Freshwater fish produce large amounts of urine, because they have abundant water
• The pattern of movement of blood and water over the gill structure is called Counter-current flow
• A fish has Single loop circulation
• A sharks gills have slits with no bony covering
• Bony fishes gills have slits covered by an operculum
• A shark will die if it stopped swimming as they have no operculum to pump water
• Bony fish are able to stay still (pumping water over its gills) using their Operculum
• Sharks stay afloat in the ocean using Oily livers
• Bony fish stay afloat while swimming using Swim bladders filled with air
• Sharks use a modified large intestine called a Spiral valve which is designed to give Maximum Surface area in small space
• Some Sharks are warm blooded and Swim constantly allowing them to have warmth
• fish lateral line function: to sense is pressure
• sharks ampullae of lorenzini : sense electro magnetic radiation

Teleost?

• Ray finned bony fish

Coelacanth?

• Lobe finned
• Three orders of amphibians?
  • Apoda
  • Anura
  • Urodela

Examples of Amphibians:

• urodela: Salamanders
• Anura: Frogs
• Apoda: Caecillians

External or internal reproduction:

• Amphibian reproduction is external
• Frog and toad reproduction is called Amplexis
• 33% of all frogs are endangered
• Missouris giant salamander is Called Hellbender
• Special about the amphibians skin is that it allows them to breath and is water permeable

Stages of a Frog?

• egg, tadpole, froglet, Adult frog
• Amphibians use Lungs / Skin to breathe
• Amphibians hearts have 2 loops of circulation and 3 chambers in the heart

Largest Shark Ever Discovered?

• Megalodon
• Sharks are able to extend their jaws because their skulls are not connected to one another
• Sharks are able to be the largest fish in the oceans Because Cartilage makes them lighter but still Strong

Reptiles and Birds

Reptiles

1. Four Types of Reptiles:
   • Crocodilian
   • Serpentes
   • Lacertilia
   • Testudines
2. Examples of Each Type:
   • Crocodile
   • Snake
   • Lizard
   • Turtles
3. Reptiles are ectothermic and need to bask and then get out of the sun during the day.
4. Reptile skin is dry and water tight.
5. What is the amniotic egg and what problem did it solve? Whatertight Shelled egg They can lay eggs on land
6. Heat sensing organ is some snakes? Pit organ
7. How do snake smell their prey? With the tongue
8. What is the The organ called that snakes use to smell their prey? Jacobsons organ
9. Why is it incorrect to refer to a snake as venomous? venom has to be injected

Identifying venomous Snakes in MIssouri:

• Triangle head
• Slit Pupils
• Pit organs
• Thick body
• Rattle

1. Difference between carapace and the plastron on a turtle or tortoise? carapace=top plastron = Bottom
2. What is the difference between ovoviviparous and oviparous? Ovo: Keep eggs internally ovip: Lays eggs

Birds

• Unique about a birds skeleton? rigid hollow
• Bird's Breast Bone: Large and fused into one solid piece for large muscle attachment (flight).
• Two Types of Feathers:
  • Contour
    • Down
• Contour Feather: for flight
  *Down Feather: to preserve haet
• Bird's Lungs: Surrounded by air sacs (7 way air flow).
• Bird's Heart and Lungs:
• higher metabolism
• makes them endothermic
• 
  *Reptiles Heart: 3 chamber ((crocodile : 4 chamon)
  *Bird Heart: chamber