Biology 1108 (KSU) Study Guide Exam 3
Questions with Correct Answers 2026
Porifera - CORRECT ANSWER –
-Sponges
- basal group
- No specialized tissues
- Spicules (made up of calcium carbonate and silica)
- Internal cells (choanocytes)
- Filters gallons of water to catch food particles
Cnidaria - CORRECT ANSWER --jellyfish, anemones, corals, hydra
-radially symmetric
- endoderm and ectoderm
- cnidocytes
- sessile and floating animals
- one cavity (mouth/anus)
- corals have photosynthetic zooxanthellae living between their endo and ectoderm
Platyhelminthes - CORRECT ANSWER -- mesoderm evolves
- mouth and anus separate
-Tapeworms, flatworms, liver flukes
- free-living and parasitic
- no limbs
- simple similar to a. Coela (basal of bilateral)
,Mollusca - CORRECT ANSWER -- oysters, clams, snails, slugs, octopi, squid
- head, foot and mantle
- bivalves
- gastropods (snails/slugs), chepalopds (squids/octopus)
- most marine but some terrestrial and freshwater
- soft- bodied animals
- hard calcium carbonate shell
Annelida - CORRECT ANSWER -- Segmented worms - convergent evolution w/ arthropods
- earthworms, leeches, many intertidal saltwater species, and tubeworms
- Tubeworms- have chemoautotrophic bacteria living in their tissues (H2S)
- bacteria break down H2S and provide chemical bonds
- make roots
Nematoda - CORRECT ANSWER -- roundworms
- parasites of both plants and animals
- C. elegans- 1st animal genome to be fully sequenced (1998)
Arthropoda - CORRECT ANSWER -(⅔ of all described species of animals)
- all earth habitats
- Segmented invertebrates with jointed appendages
- Crustaceans (crabs, lobsters, shrimp, barnacles)
- Chelicerates (horeshoe crabs scorpions, spiders)
- Mynapods (millipedes, centipedes)
- Hexapods (insects)
, - Trilobites (extinct, 270 mya)
- external skeleton made of polysaccharide chitin
- crustaceans have calcium carbonate in exoskeleton
- horseshoe crabs- antibody testing (blue blood)
Echinodermata - CORRECT ANSWER -- sessile marine animals
- includes sea stars, brittle stars, sea urchins, sea cucumbers
- shared common ancestor for Echinodermata and Chordates
- radial symmetry evolved from the bilateral symmetry of ancestors
- spiny skin covers a calcium carbonate skeleton
Chordata - CORRECT ANSWER -- Lancelets (first diverged species)
- tubular body, no eyes, and no brain
- ancestor of all chordates had tubular body
-
synamorphies can be seen in embryonic stage and/or at maturity (post anal tail in human
embryos)
Know which phyla are involved in the debate over who is the first-
branching animal lineage, which hypothesis is best supported by the recent research paper,
and what that implies about the common ancestor of all animals regarding tissue and com
plexity - CORRECT ANSWER --
Porifera (supported by amino acids, maximum parsimony, morphological similarities) (bette
r genetic model), Ctenophora (comb jellies), and Placozoa.
- common ancestor - no specialized tissues, no symmetry, spicules
What phylums belong to the Deuterostomes? - CORRECT ANSWER -- Deuterostomes
- Echinoderms
Questions with Correct Answers 2026
Porifera - CORRECT ANSWER –
-Sponges
- basal group
- No specialized tissues
- Spicules (made up of calcium carbonate and silica)
- Internal cells (choanocytes)
- Filters gallons of water to catch food particles
Cnidaria - CORRECT ANSWER --jellyfish, anemones, corals, hydra
-radially symmetric
- endoderm and ectoderm
- cnidocytes
- sessile and floating animals
- one cavity (mouth/anus)
- corals have photosynthetic zooxanthellae living between their endo and ectoderm
Platyhelminthes - CORRECT ANSWER -- mesoderm evolves
- mouth and anus separate
-Tapeworms, flatworms, liver flukes
- free-living and parasitic
- no limbs
- simple similar to a. Coela (basal of bilateral)
,Mollusca - CORRECT ANSWER -- oysters, clams, snails, slugs, octopi, squid
- head, foot and mantle
- bivalves
- gastropods (snails/slugs), chepalopds (squids/octopus)
- most marine but some terrestrial and freshwater
- soft- bodied animals
- hard calcium carbonate shell
Annelida - CORRECT ANSWER -- Segmented worms - convergent evolution w/ arthropods
- earthworms, leeches, many intertidal saltwater species, and tubeworms
- Tubeworms- have chemoautotrophic bacteria living in their tissues (H2S)
- bacteria break down H2S and provide chemical bonds
- make roots
Nematoda - CORRECT ANSWER -- roundworms
- parasites of both plants and animals
- C. elegans- 1st animal genome to be fully sequenced (1998)
Arthropoda - CORRECT ANSWER -(⅔ of all described species of animals)
- all earth habitats
- Segmented invertebrates with jointed appendages
- Crustaceans (crabs, lobsters, shrimp, barnacles)
- Chelicerates (horeshoe crabs scorpions, spiders)
- Mynapods (millipedes, centipedes)
- Hexapods (insects)
, - Trilobites (extinct, 270 mya)
- external skeleton made of polysaccharide chitin
- crustaceans have calcium carbonate in exoskeleton
- horseshoe crabs- antibody testing (blue blood)
Echinodermata - CORRECT ANSWER -- sessile marine animals
- includes sea stars, brittle stars, sea urchins, sea cucumbers
- shared common ancestor for Echinodermata and Chordates
- radial symmetry evolved from the bilateral symmetry of ancestors
- spiny skin covers a calcium carbonate skeleton
Chordata - CORRECT ANSWER -- Lancelets (first diverged species)
- tubular body, no eyes, and no brain
- ancestor of all chordates had tubular body
-
synamorphies can be seen in embryonic stage and/or at maturity (post anal tail in human
embryos)
Know which phyla are involved in the debate over who is the first-
branching animal lineage, which hypothesis is best supported by the recent research paper,
and what that implies about the common ancestor of all animals regarding tissue and com
plexity - CORRECT ANSWER --
Porifera (supported by amino acids, maximum parsimony, morphological similarities) (bette
r genetic model), Ctenophora (comb jellies), and Placozoa.
- common ancestor - no specialized tissues, no symmetry, spicules
What phylums belong to the Deuterostomes? - CORRECT ANSWER -- Deuterostomes
- Echinoderms
