Porifera
What are pinacocytes?
Are cnidarians herbivores or carnivores?
Carnivores. They trap and eat microscopic plankton in the water.
What are the two groups of flatworms?
Tapeworms and Planarians
What are two main groups of annelids?
Corals are what type of cnidarian?
They are a polyp. They build external structures made of calcium.
What are spicules?
They are the skeleton of sponges to support the body. They are made of calcium.
What are the three main groups of cnidarians?
Anemones, jellyfish and polyps
Describe the interaction of planarians.
Planarians: Free-living in water. Can perceive light, but they don't have eyes. They have a group of cells that sense light.
What are the defining physical features of annelids?
They have a body made of segments and they have a digestive system and a circulatory system.
What are the physical characteristics of nematodes or roundworms?
They have pointed tips.
The body is NOT divided into rings.
They reproduce sexually.
Explain sponge nutrition.
Sponges filter food particles out of the water that flows through them. Choanocytes (collar cells) create a stream of water flowing through the sponge, which they filter.
Where do anemones live? Where do jellyfish live?
Anemones live on the ocean floor, attached to rocks. Jellyfish swim in the ocean freely.
Describe interaction of tapeworms.
Tapeworms: Parasites. Can't perceive light. Some have hooks or suckers to anchor themselves to their host.
How do annelids reproduce?
The majority reproduce sexually. Some are hermaphrodites and can self-fertilise or cross-fertilise with another individual.
What is runoff?
Describe the function of the osculum.
It is the large opening. Water with carbon dioxide and waste substances is expelled through the osculum.
How can cnidarians bend in any direction?
They have two sets of muscles that they contract with signals from their nerves.
Describe differences in reproduction between tapeworms and planarians.
Tapeworms: hermaphrodites that can self-fertilise, but cross-fertilisation is more common.
Planarians: Sexual and asexual. Sexual planarians are hermaphrodites. Planarians can be cut into pieces and each piece can regenerate into a complete organism.
What are the main differences between nematodes and annelids?
Nematodes don't have segments. Nematodes also have pointed ends while annelids do not.
What is a dead zone? Name one.
A dead zone is an area where aquatic life has died because of the hypoxic (or anoxic) conditions caused by eutrophication.
The Gulf of Mexico dead zone. It is located at the mouth of the Mississippi River.
What are amebocytes? What is their function?
They are cells with pseudopods. Their function is transport nutrients from choanocytes to pinacocytes.
What are cnidocytes and how do they function?
They are a type of stinging cell in tentacles that contian toxins, and a filament. When the tentacles are touched, the filament extends, and poisons the prey or attacker.
What is the function of the scolex in tapeworms?
The scolex is the head. It has hooks and suckers. It attaches the worm to the inside of the intestines.
Most annelids live in humid environments. Why?
Annelids do not have lungs. Most annelids breathe by absorbing oxygen through their moist skin. This is called cutaneous respiration.
Describe the process of eutrophication.
Eutrophication is a cycle of algal blooms, caused by nutrient runoff, followed by mass decomposition which consumes the oxygen in the water, leading to the death of aquatic life.