unit 3 biology 11

What trait first appeared in Phylum Porifera?

Multicellularity, which is the precursor for complex life.

Out of the three sponge classes, what is the Calcarea, focus on its spicules.

spicules are made of calcium carbonate

Out of the three sponge classes, what is the Hexactinellida, focus on its spicules.

Spicules are made of silica, AKA glass sponge

Out of the three sponge classes, what is the demospongiae, focus on its spicules.

skeletons are made of spicules and spongin,

Most diverse class of sponges

Where do sponges live?

In the ocean, found at all levels of the ocean.

How does water and wastes move through a sponge?

Water flows in through the ostia,(surrounded by cells that make the pore channel called porocytes

The porocytes can expand and contract to control the amount of water that comes into the spogocoel

The water enter the spongocoel

The water goes out the top opening called the osculum

What do sponges eat? Be specific

Marine plankton = bateria, archaeabacteria, algae, protist

How does a sponge catch and digest food

The water the moving in the spongocoel have planktons inside(bacteria, algae, ) which are caught by the flagellum of the choanocytes,

Those planktons are pushed into the collar shaped part of the choanocytes and the foods are absorbed by the amoebocytes and digested.

How does a sponge reproduce?

Hermaphrodites

Sexually: creates sperm and eggs from the choanocytes at different times to avoid self fertilization, the sperm leaves through the osculum and the sperm is captured by another sponges choanocytes and absorbed to mesohly, where the egg is fertilized.

Asexual: budding , fragmentation and gemmules.

Why are sponges considered the most primitive animal? What systems are they missing?

They dont have brain. Respiratory, circulatory or excretory system and no organs, no tissues

Name 3 reasons why sponges (as a species) are difficult to kill off (they’ve survived every

mass extinction so far….)

Can survive in freezing temperatures

they survive by only eating bacteria

During unfavorable conditions, sponges create gemmules

be able to define: ectoderm, pinacocytes, endoderm, choanocytes, mesohyl, flagellum,

spicules, spongin, ostia, spongocoel, osculum, porocytes, amoebocytes, hermaphrodite,

gemmules

Outerlayer called the ectoderm, made of plate like cells called pinacocytes, acts as the skin/ protection

middle layer: called mesohyl, made of spongin and spciules, spongin is a protein that holds sponges together, spicules are internal skeletal system needles like made of calcuim carbonate

Inner layer: called entoderm and lined with specialized cells called choancytes

What trait first appeared in Phylum Cnidaria? (see the cladogram) 

Tissues

which animals belong to these classes
Class scyphozoa
class anthozoa

Jellyfish: Class scyphozoa
Sea anemones and corals : class anthozoa

What two unique traits does Phylum Cnidaria have?  

A nervous system and specialized structed called the GVC

What is the importance of having tissues? 

allows for presence of organ development
specialized structure

What are three things that the gastrovascular cavity does in Cnidarians? 

does the job of digestive system, circulatory system , excretory system.

does Cnidarians have a mouth and a anus? and why

cnidarians eat and waste in the same hole.

Explain simple diffusion, and how Cnidarians depend on it for gas exchange  

Simple diffusion is the movement of molecules from an area of high concentration to an area of low concentration without using energy. Cnidarians rely on simple diffusion for gas exchange because oxygen diffuses from the surrounding water into their thin bodies, while carbon dioxide diffuses out into the water.

Describe the nervous system of Cnidarians  (Understand the connection between mobility and having a nervous system  )

the nerve net (hydra) acts as a simple nervous system, it spreads all over the body and is made of neurons that process sensory information,
stationary cnidarians were mobile at some point as a larvae, however later in their reproductive cycle they become anemones, being stationary and not needing a nervous system to sense their environment to find food.

What is the importance of corals? What is coral bleaching and how does it happen?  

Corals have tiny algaes living inside them called Zooxanthellae, these give corals their colour and food through photosynthesis, however when coral is stressed through warm ocean water or other factors the coral expels the zooxanthellae, making them appear white (bleached) and the coral can no longer build its calcium carbonate, if the coral does not regain its zooxanthellae, it can die.

What are the names of the three phyla containing the worms? What are their common names?  

Phylum Platyhelminthes (flatworms)
Phylum Nematoda (round worm)
Phylum Annelida (earthworms)

What trait first appeared in Phylum Platyhelminthes? (see the cladogram)  

Bilateral symmetry (if cut in half looks symmetrical)

What are the two classes of Phylum Platyhelminthes? What animal represents each class? 

Class Turbellaria (Flatworms)
Class Cestoda (Tapeworms)

What is the importance of having bilateral symmetry? What is cephalization?  

It allows for a presence of a head(cephalization) which lets them have centralized nervous system and a ganglia (primitive brain)

What symmetry do sponges and Cnidarians have?  

Porifera (no symmetry)
Cniderian (Radial symmetry)