Lab 1 Kingdom Animalia: Phyla Porifera, Cnidaria, Platyhelminthes

What is a bauplan and what are the 3 types?

a body plan

1) asymmetry

2) radial symmetry

3) bilateral symmetry

What word means to have 2 tissue layers?

diploblastic

What is a nerve net?

a coordination of complex sensory structures which detect light and orientation; a network of nerve cells

What is the term for stinging cells which eject toxins?

cnidocytes/nematocytes

What 2 significant benefits do spicules provide to sponges?

1) They provide a scaffold-like structure that helps to maintain body structure

2) They help to deter predators

What is the function of choanocytes?

to trap food particles in the stream of water and store nutrients

What are 2 functions of a sponge’s amoebocytes?

1) transportation of nutrients

2) waste removal

What is the difference between Porifera and Cnidaria in terms of their germ layers?

Porifera have 1 germ layer whilst Cnidaria have 2 germ layers (diploblastic)

How do sponges accomplish cross fertilization?

they are monoecious/hermaphroditic

What type of symmetry do Cnidarians have?

radial symmetry

How do Hydra asexually reproduce?

via budding

What is budding?

a form of asexual reproduction that results from the outgrowth of a part of a cell or body region, leading to a separation from the original organism into two individuals

What is the nervous system of Cnidarians like?

nerve net

What are the 2 functions of the hydrostatic skeleton of Cnidarians?

1) To keep pressure of the fluids within an organism to help it hold its shape without the animal having bones or solid skeletal elements (think jellyfish)

2) Allows for movement

What is the function of cnidocytes?

to eject toxins

What are eyespots?

structures that can detect the presence and direction of light; look like goofy little eyes on what appears to be the head of Planaria

What are auricles?

earlike sensors that triangulate and allow the organism to follow the chemical trail from food items; appear as little bumps on what looks like the head of Planaria

What are proglottids?

areas in cestoda (tapeworms specifically) that contain both male and female reproductive systems

How do planarians feed?

their pharynx extends when food is detected to intake it

Where are the mouth and pharynx located on planarians?

ventrally

Why is it unusual for planarians to feed the way they do despite being animals with bilateral symmetry?

The anus/waste secreting body part is typically found ventrally in other animals. Additionally, the anus and mouth are close together which allows for the entry and exit of things into the animals body

How many germ layers do Platyhelminthes have?

3

How to flatworms perform gas exchange?

They perform gas exchange via diffusion across their surfaces

Why is it important that flatworms are flat?

they do not have a respiratory system and being flat allows for diffusion to occur

What structures are used for nitrogenous waste excretion in flatworms?

flame cells