BROOKS BIODIVERSITY UNIT 3 EXAM
SCRIPT 2026 TESTED QUESTIONS WITH
ACCURATE SOLUTIONS STUDY RESOURCE
●● 3 Classes of Annelida.
Answer: 1. Class Polychaeta
2. Class Oligochaeta
3. Class Hirudinea
●● 3 tagma found in Arthropods.
Answer: 1. Head
2. Thorax
3. Abdomen
●● The most abundant class of Annelids are:.
Answer: Polychaetes
●● Nereis is an example of this phylum and class.
Answer: Phylum - Annelida
Class - Polychaeta
,●● Coelom of Phylum Hemichordata.
Answer: Deuterostomes
●● Features of Hemichordata.
Answer: Pharyngeal gill slits
Hollow nerve cord
Burrowing marine worms with a proboscis
Ex: Acorn Worm
●● General characteristics of Phylum Chordata (during some stage of
their life).
Answer: 1. Notochord
2. Dorsal Hollow Nerve Cord
3. Pharyngeal Gill Slits
4. Post Anal Tail
●● Nonvertebrate Chordates.
Answer: Subphylum Urochordata
Subphylum Cephalochordata
●● Features of Subphylum Urochordata.
Answer: -Free swimming larvae that have all 4 Chordate Characteristics
,-Sessile adults retain only the pharyngeal gill slits
-Ex: Trunicates, Sea Squirts, and Larvaceans
●● Features of Subphylum Cephalochordata.
Answer: All four chordate characteristics are present to adulthood
Ex: Lancelets
●● Paedomorphosis.
Answer: Adult in a child body
●● What is possibly the first vertebrate?.
Answer: Pikia
●● Evolution of the heart -.
Answer: Started with 2 chambered hearts eventually moved to 4
chambers
●● Class Condrichthyes - Sharks and Rays features.
Answer: Skeleton mostly cartilage
Notochord persistent throughout its life
Subterminal mouth (on bottom of the body)
mouth below rostrum
, 2 chambered heart
Do not possess an operculum
Lack swim bladder
Buoyancy is through oils in the liver
●● Chondrichthyes - Shark scale type.
Answer: Placoid
●● What is one of the most abundant fossils and why?.
Answer: Shark teeth because they can regenerate and are calcified
●● Ratfish (chimaera) possess an operculum and is considered a
transition animal to.
Answer: bony fish
●● Cartilaginous fish often produce.
Answer: electrical shocks
●● Sharks and skates rarely get tumors thanks to.
Answer: their cartilaginous skeleton
●● Class Osteichthyes - Bony Fish features.
SCRIPT 2026 TESTED QUESTIONS WITH
ACCURATE SOLUTIONS STUDY RESOURCE
●● 3 Classes of Annelida.
Answer: 1. Class Polychaeta
2. Class Oligochaeta
3. Class Hirudinea
●● 3 tagma found in Arthropods.
Answer: 1. Head
2. Thorax
3. Abdomen
●● The most abundant class of Annelids are:.
Answer: Polychaetes
●● Nereis is an example of this phylum and class.
Answer: Phylum - Annelida
Class - Polychaeta
,●● Coelom of Phylum Hemichordata.
Answer: Deuterostomes
●● Features of Hemichordata.
Answer: Pharyngeal gill slits
Hollow nerve cord
Burrowing marine worms with a proboscis
Ex: Acorn Worm
●● General characteristics of Phylum Chordata (during some stage of
their life).
Answer: 1. Notochord
2. Dorsal Hollow Nerve Cord
3. Pharyngeal Gill Slits
4. Post Anal Tail
●● Nonvertebrate Chordates.
Answer: Subphylum Urochordata
Subphylum Cephalochordata
●● Features of Subphylum Urochordata.
Answer: -Free swimming larvae that have all 4 Chordate Characteristics
,-Sessile adults retain only the pharyngeal gill slits
-Ex: Trunicates, Sea Squirts, and Larvaceans
●● Features of Subphylum Cephalochordata.
Answer: All four chordate characteristics are present to adulthood
Ex: Lancelets
●● Paedomorphosis.
Answer: Adult in a child body
●● What is possibly the first vertebrate?.
Answer: Pikia
●● Evolution of the heart -.
Answer: Started with 2 chambered hearts eventually moved to 4
chambers
●● Class Condrichthyes - Sharks and Rays features.
Answer: Skeleton mostly cartilage
Notochord persistent throughout its life
Subterminal mouth (on bottom of the body)
mouth below rostrum
, 2 chambered heart
Do not possess an operculum
Lack swim bladder
Buoyancy is through oils in the liver
●● Chondrichthyes - Shark scale type.
Answer: Placoid
●● What is one of the most abundant fossils and why?.
Answer: Shark teeth because they can regenerate and are calcified
●● Ratfish (chimaera) possess an operculum and is considered a
transition animal to.
Answer: bony fish
●● Cartilaginous fish often produce.
Answer: electrical shocks
●● Sharks and skates rarely get tumors thanks to.
Answer: their cartilaginous skeleton
●● Class Osteichthyes - Bony Fish features.
