Chapter 33 terms and concepts Flashcards
Discuss how sponges are different from all other major groups of animals
They are basal animals, that lack tissues. They are sedentary and live in both marine or fresh water environments, and are also filter feeders
Characterize cnidarians and describe their body plans
A wide range of both sessile and motile forms of organisms, including jellies, corals and hydras.
Diplopastic, radially symmetrical organisms. They also have a basic body plan of a sac with a central digestive compartment: gastrovascular cavity
Cnidarian body plans
A polyp: adheres to a substrate by opposite end of its body from the mouth/anal opening
A medusa has a bell-shaped body with its mouth on underside
Characteristics of lophotrochozoans
- Widest range of animal body form, related mostly by molecular data rather than morphological similarities
They have triploblastic development, and most have a coelom and a digestive tract with two openings
They have a lophophore - a crown of ciliated tentacles around their mouth that is used for feeding. Most have a true coelom
Body plan of flatworms - do they have a true coelom?
Many are parasites.
They are acoelomates, meaning they lack a body cavity. They also have a gastrovascular cavity, with only one opening
General characteristics of Ecdysozoans, including nematodes and arthropods
Most ecdysozoans are covered by a tough outer coating called the cuticle
Arthropods body plan: they have segmented, hard exoskeleton and jointed appendages, which can be modified for functions such as walking, feeding, sensory reception, reproduction, and defense. They have eyes, olfactory receptors, and antennae that function in touch and smell. They also have an open circulatory system in which hemolymph is circulated into spaces surrounding tissues and organs
Spider and lobster (arthropods) body segments
They have a cephalothorax - which is a fused head and thoracic region designed for sensing, feeding and locomotion
Abdomen: houses digestive, reproductive and respiratory organs
Compare/Contrast the major phylogenetic groups of animals
Sea stars and sea urchins are echinoderms (phylum Echinodermata)
Vertebrates (animals that have a backbone) are in phylum chordata. Which they constitute clade deuterostomia, which is mainly defined by DNA similarities
