Bio lab quiz - animal phylogenetic tree.

What are the defining characteristics of Porifera?

No true tissues, mostly asymmetrical, intracellular digestion, spicules, choanocytes, and amoebocytes.

What are spicules?

Structural supports found in many sponges (Porifera).

What are choanocytes?

Flagellated collar cells in sponges that create water currents and capture food.

What are amoebocytes?

Mobile sponge cells that help transport nutrients and perform other functions.

Which phylum has no true tissues?

Porifera.

What are the defining characteristics of Cnidaria?

Radial symmetry, gastrovascular cavity, cnidocytes with nematocysts, and polyp/medusa forms.

What are cnidocytes?

Specialized stinging cells in Cnidaria.

What are nematocysts?

Stinging capsules found inside cnidocytes.

What are polyp and medusa forms?

Two cnidarian body forms: polyp is typically attached; medusa is usually free-swimming.

What is radial symmetry?

Body parts arranged around a central axis.

Which phylum includes jellyfish and corals?

Cnidaria.

What are the defining characteristics of Platyhelminthes?

Flat body, parenchyma, bilateral symmetry, and typically a gastrovascular cavity.

What is parenchyma in flatworms?

Tissue that fills spaces between internal organs.

Which phylum has a flat body and parenchyma?

Platyhelminthes.

What are the defining characteristics of Mollusca?

Head-foot region, visceral mass, mantle, and commonly a radula.

What is the mantle?

Mollusk tissue that covers the visceral mass and may secrete a shell.

What is the visceral mass?

The mollusk body region containing most internal organs.

What is a radula?

A feeding structure used by many mollusks to scrape or process food.

Which phylum includes snails, clams, and octopuses?

Mollusca.

What are the defining characteristics of Annelida?

Segmented body and chaetae (bristles).

What are chaetae?

Bristle-like structures in many annelids used for movement or anchoring.

Which phylum includes earthworms and leeches?

Annelida.

What are the defining characteristics of Arthropoda?

Segmented body with tagmatization, exoskeleton, jointed appendages, cuticle, and ecdysis.

What is tagmatization?

Grouping of body segments into specialized functional regions.

What is an exoskeleton?

A supportive external skeleton.

What are jointed appendages?

Movable, articulated limbs characteristic of arthropods.

Which phylum includes insects, spiders, and crabs?

Arthropoda.

What are the defining characteristics of Nematoda?

Unsegmented roundworms with a cuticle that is shed by ecdysis.

What is ecdysis?

Molting: shedding an outer cuticle or exoskeleton.

Which two phyla share cuticle and ecdysis?

Arthropoda and Nematoda.

What are the defining characteristics of Echinodermata?

Deuterostomes with a water vascular system and typically pentaradial adult symmetry.

Which phylum includes sea stars and sea urchins?

Echinodermata.

What are the defining characteristics of Chordata?

Notochord, dorsal hollow nerve cord, pharyngeal slits, and post-anal tail at some developmental stage.

Which phyla are deuterostomes on the lecture tree?

Echinodermata and Chordata.

Which phyla are protostomes on the lecture tree?

Platyhelminthes, Mollusca, Annelida, Arthropoda, and Nematoda.

What is the difference between protostomes and deuterostomes?

Traditionally, the blastopore becomes the mouth in protostomes and the anus in deuterostomes.

What does diploblastic mean?

Develops two embryonic germ layers.

What does triploblastic mean?

Develops three embryonic germ layers.

What is bilateral symmetry?

A body plan that can be divided into left and right mirror-image halves.

Which phyla are paired as close relatives on the lecture tree?

Mollusca with Annelida; Arthropoda with Nematoda; Echinodermata with Chordata.