BIO 182 EXAM 3 2026 MOLECULAR BIOLOGY
REVIEW QUESTIONS ANSWERS VERIFIED
GUIDE
◉ Five important points about the relationships among living
animals are reflected in their phylogeny.
Answer: All animals share a common ancestor
Sponges are basal animals
Eumetazoa is a clade of animals with true tissues
Most animal phyla belong to the Bilateria clade
Three major clades of bilaterian animals (all invertebrates, except
Chordata which are vertebrates)
◉ 95% of animals are:.
Answer: invertebrates (no backbones)
◉ Deuterostomia includes.
Answer: Hemichordates, echinoderms and chordates
◉ Hemichordates.
Answer: Acorn worms
,◉ Echinoderms.
Answer: sea stars, sea urchins, sea cucumbers
◉ Chordates.
Answer: fish, amphibians, reptiles, birds, mammals
Includes: two groups of invertebrates, urochordates, and
cephalochordates
Bilaterian Deuterostomia
◉ Ecdysozoa.
Answer: Invertebrate clade that shed their exoskeletons through a
process called ecdysis
◉ Ecdysis.
Answer: process in which invertebrates shed their exoskeletons
◉ Lophotrochozoa.
Answer: Bilaterian invertebrate clade that have a lophophore and
trochopore larva
◉ Lophophore.
,Answer: Feeding structure
Lophotrochozoans have this
◉ Trochophore Larva.
Answer: Distinctive larval stage observed in annelids and molluscs.
◉ Example of a species of deuterostome with a lophophore.
Answer: Christmas Tree Worm
◉ Invertebrates.
Answer: Lack backbone
95% of known animal species
Morphologically diverse
Almost within every habitat on Earth
◉ Porifera.
Answer: Sponges
Sedentary
Marine/Fresh waters
Lacks true tissues and organs
◉ Filter feeders.
, Answer: (Sponges)
captures food particles suspended in water that passes through their
body
◉ Spongocoel.
Answer: Water is drawn through pores into this cavity.
◉ Osculum.
Answer: Water goes out through this opening.
◉ Choanocytes.
Answer: Flagellated collar cells
Generates a water current through sponge and ingest suspended
food
◉ Mesohyl.
Answer: Sponges consist of a gelatinous noncellular _____ layer
between two cell layers
◉ Amoebocytes.
Answer: Found in the mesohyl and play roles in digestion and
structure
REVIEW QUESTIONS ANSWERS VERIFIED
GUIDE
◉ Five important points about the relationships among living
animals are reflected in their phylogeny.
Answer: All animals share a common ancestor
Sponges are basal animals
Eumetazoa is a clade of animals with true tissues
Most animal phyla belong to the Bilateria clade
Three major clades of bilaterian animals (all invertebrates, except
Chordata which are vertebrates)
◉ 95% of animals are:.
Answer: invertebrates (no backbones)
◉ Deuterostomia includes.
Answer: Hemichordates, echinoderms and chordates
◉ Hemichordates.
Answer: Acorn worms
,◉ Echinoderms.
Answer: sea stars, sea urchins, sea cucumbers
◉ Chordates.
Answer: fish, amphibians, reptiles, birds, mammals
Includes: two groups of invertebrates, urochordates, and
cephalochordates
Bilaterian Deuterostomia
◉ Ecdysozoa.
Answer: Invertebrate clade that shed their exoskeletons through a
process called ecdysis
◉ Ecdysis.
Answer: process in which invertebrates shed their exoskeletons
◉ Lophotrochozoa.
Answer: Bilaterian invertebrate clade that have a lophophore and
trochopore larva
◉ Lophophore.
,Answer: Feeding structure
Lophotrochozoans have this
◉ Trochophore Larva.
Answer: Distinctive larval stage observed in annelids and molluscs.
◉ Example of a species of deuterostome with a lophophore.
Answer: Christmas Tree Worm
◉ Invertebrates.
Answer: Lack backbone
95% of known animal species
Morphologically diverse
Almost within every habitat on Earth
◉ Porifera.
Answer: Sponges
Sedentary
Marine/Fresh waters
Lacks true tissues and organs
◉ Filter feeders.
, Answer: (Sponges)
captures food particles suspended in water that passes through their
body
◉ Spongocoel.
Answer: Water is drawn through pores into this cavity.
◉ Osculum.
Answer: Water goes out through this opening.
◉ Choanocytes.
Answer: Flagellated collar cells
Generates a water current through sponge and ingest suspended
food
◉ Mesohyl.
Answer: Sponges consist of a gelatinous noncellular _____ layer
between two cell layers
◉ Amoebocytes.
Answer: Found in the mesohyl and play roles in digestion and
structure
