warm up. name that symmetry
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Warm up. Name that symmetry. Answer: Bilateral. Answer: Radial. Answer: Radial. Sea sponge. Answer: Asymmetry!. Asymmetry – non-symmetrical. "I drink no more than a sponge" Francis Rabelais. Phylum: Porifera. - PowerPoint PPT PresentationTRANSCRIPT
Warm up.
Name that symmetry
Answer: Bilateral
Answer: Radial
Answer: Radial
Answer: Asymmetry!Sea sponge
Asymmetry – non-symmetrical
Phylum: Porifera"I drink no more than a sponge" Francis Rabelais
Phylum Porifera
• From Greek ‘poros’ meaning ‘passage’ or ‘pore’ Sponges have tiny openings all over their body • Therefore Porifera = “pore-bearers”• Most ancient and primitive of all animals• Estimated 5000-10000 species • Most sponges are marine, some live in freshwater
Where are they on the tree of life?
• You tell me?
“I never wanted to be different; I just wanted to be me”
• Sponges are different than other animals.• Originally thought to be plants because “sessile”• Have no: Mouth, head, muscles, nervous
system, digestive tract, circulatory organs, true tissue layers, organ system.
• Long thought to be an evolutionary dead end however recently believed to be at the base of the animal tree of life.
Sessile: “fixed in one place”
What do they have?Why are they an animal?
• Collagen- all animals use collagen as an essential structural protein
• Animal embryonic development
• “Motility” of most cells within the sponge
Motile
Structure and Function in Porifera-The 4 Cells
• Epidermal cells
• Pore Cells
• Collar Cells (choanocyte)
• Amoebocytes
Epidermal
- Flat cells form the outer covering.- Respire and excrete via diffusion.
Pore cells
- Cylindrical cells which allow water and food to enter the sponge- The flow of water is driven by current and by
collar cells
Collar cells (choanocyte)
- Inner cell layer of a sponge- Have a flagellum which draws water into the sponge-flagellum also drives food into the collar where they are ingested into the cell body
Amoebocytes
• amoeba-like cells that crawl around the jellylike inner layer of the sponge
• Deliver food and O2
• Absorb nutrients and remove wastes• Make SPICULES which create sponge skeleton• Carry sperm to eggs
http://www.biologyjunction.com/sponges__cnidarian_notes_b1.htm
Activity
• With a partner try and remember the 4 cell types
• Draw the four cell types• Label their parts.• Write brief definition of what they do• Gallery walk (see other drawings get ideas
how other people do their work)
How does a sponge stay standing?
• Spicules • Spongin
Head to Head
Spicules• Created by Amoebocytes • Made from either: -chalklike calcium carbonate (CaCO3) -or glasslike silica (SiO2)• Form the delicate skeleton of the
sponge
Spongin• Softer sponges (like the
ones you can buy to use in the bath) are made up of fibrous proteins called spongin.
• Some sponges contain both spicules and spongin
Spongin Spicules
Evolution of Spicules
Other key words
• Spongocoel – hollow body in the sponges interior. (think coelom)
• Osculum- Opening where water exits the sponge
• Spicules – the skeleton of the sponge (more later)
How does a sponge eat?
• ..\..\..\Lesson Videos\Biology 11\Sponge Feeding.mov.flv
How does a sponge eat?
• Sponges are filter feeders – they sift microscopic food particles from the water that passes through them• All digestion is intracellular • Food particles stick to the collar cells
Collar cells either digest the food or pass them on to the ? (what else digests/delivers food)Amoebocytes
The water flowing through a sponge serves as its respiratory, excretory, and circulatory system.
• Sponges pump huge amounts of water through their body every day
• Roughly one tonne water per ounce of food
Reproduction
Asexual reproduction• “Budding” – a small growth
forms and falls off the sponge starting a new sponge
• “regeneration” Sponges can regenerate from broken pieces
• “Gemmules” sphere-shaped collections of amoebocytes surrounded by spicules. They leave sponge, settle, and wait for improved conditions
Sexual reproduction• Hermaphrodites (both male
and female sexual organs)• Most fertilization is
hermaphroditic• “Broadcast” method of
sperm release. Masses of sperm released into water
• Amoebocytes carries sperm to egg when received.
Gemmulles• “Little gems of life”? “Survival pods”?
• Remember it your way.
• Sphere-shaped collections of amoebocytes surrounded by spicules
• leave sponge, settle, and wait for improved conditions
Gemmules
• Can survive extreme temperatures or drying out
• Some are resistant to freezing• Full of amoebocytes which can grow into any
type of cell necessary for survival
• Why would sponges have evolved Gemmules?
Here comes the Motility
Flagellated larvae
• A sponges larvae have flagellum• Leave via ?• Osculum• Drift/ swim to their new home
• ..\..\..\Lesson Videos\Biology 11\Sponge Spawning.flv