BIOL 1104 Exam 2 Questions With
Outlined Answers
\.What are the main levels of taxonomic classification from broadest to most specific?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
\.How does taxonomy reflect evolutionary relationships?
Organisms sharing more classification levels are more closely related, indicating a more recent
common ancestor.
\.What has modern genetic analysis contributed to taxonomy?
It helps estimate evolutionary relationships, refining classifications to group organisms with
common ancestors.
\.What are the key traits of Kingdom Animalia?
Eukaryotic, multicellular heterotrophs, lack cell walls, possess tissues, most are motile, and
reproduce sexually.
\.Describe radial and bilateral symmetry.
Radial: Body parts radiate from a central axis. Bilateral: Body can be divided into two mirror-
image halves.
\.What are the two main body plans in animals?
Sac-like (incomplete digestive system) and tube-within-a-tube (complete digestive system).
\.What are the main characteristics of sponges?
No tissues or organs, asymmetrical, sessile, body with water canals, diffusion for gas exchange
\.What supports the structure of sponges?
Collagen, spongin protein, and crystalline spicules made of calcium or silica.
\.What symmetry and body forms do Cnidarians have?
Radial symmetry, polyp (sessile) or medusa (free-swimming) forms.
\.What unique cells do Cnidarians have?
,Tentacles with stinging cells called nematocysts.
\.How do Cnidarians exchange gases and excrete waste?
Through diffusion directly from cells.
\.What is dominant in Class Hydrozoa?
The polyp stage.
\.What defines Class Scyphozoa (true jellyfish)?
Medusa stage is dominant, polyp stage reduced or absent.
\.What is unique about Class Anthozoa?
They exist only as polyps and include sea anemones and corals.
\.What are the main characteristics of flatworms?
Flattened bodies, bilateral symmetry, incomplete digestive system, cephalization, gas exchange
through diffusion.
\.What are the three main classes of Platyhelminthes?
Class Turbellaria (e.g., planaria), Class Trematoda (flukes), Class Cestoda (tapeworms).
\.How do tapeworms obtain nutrients?
They lack a digestive tract and absorb nutrients directly from the host.
\.What distinguishes annelids from other worms?
Segmented bodies, bilateral symmetry, complete digestive system, closed circulatory system.
\.How do annelids perform gas exchange?
Through their skin.
\.Name two classes of Annelida and examples.
Class Hirudinea (leeches), Class Oligochaeta (earthworms).
\.What are examples of organisms in Phylum Mollusca?
Snails (Class Gastropoda), octopus (Class Cephalopoda), clams (Class Bivalvia).
\.What distinguishes Phylum Arthropoda?
Includes insects, arachnids, and crustaceans, with segmented bodies and exoskeletons.
, \.What is unique about Phylum Echinodermata?
They exhibit radial symmetry and include sea stars.
\.What is a defining feature of Phylum Chordata?
Presence of a notochord at some stage of development.
\.What are the main characteristics of Mollusca?
Open circulatory system, visceral mass with organ systems, mantle secreting shell, muscular
foot for locomotion, and well-developed head with sensory organs.
\.Name three classes within Mollusca and examples of each.
Gastropoda: Snails, slugs.
Cephalopoda: Octopi, squid, cuttlefish.
Bivalvia: Clams, oysters, mussels.
\.How do cephalopods move?
Jet propulsion using a siphon to expel water.
\.What is the movement style of nematodes, and why?
Whip-like motion due to only longitudinal muscles.
\,How does the digestive system of nematodes differ from flatworms?
Nematodes have a complete digestive system with a separate mouth and anus.
\.Give examples of nematodes and their significance.
Ascaris: Intestinal parasite in humans.
Filarial Worms: Cause diseases like elephantiasis.
Pinworms: Common intestinal parasites in the U.S.
\.What are the key features of arthropods?
Exoskeleton, jointed appendages, segmentation, bilateral symmetry, open circulation
\.Name and describe three subgroups of arthropods.
Crustacea: Crabs, lobsters; marine, hard exoskeleton.
Insecta: Ants, flies; three body parts, three pairs of legs.
Outlined Answers
\.What are the main levels of taxonomic classification from broadest to most specific?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
\.How does taxonomy reflect evolutionary relationships?
Organisms sharing more classification levels are more closely related, indicating a more recent
common ancestor.
\.What has modern genetic analysis contributed to taxonomy?
It helps estimate evolutionary relationships, refining classifications to group organisms with
common ancestors.
\.What are the key traits of Kingdom Animalia?
Eukaryotic, multicellular heterotrophs, lack cell walls, possess tissues, most are motile, and
reproduce sexually.
\.Describe radial and bilateral symmetry.
Radial: Body parts radiate from a central axis. Bilateral: Body can be divided into two mirror-
image halves.
\.What are the two main body plans in animals?
Sac-like (incomplete digestive system) and tube-within-a-tube (complete digestive system).
\.What are the main characteristics of sponges?
No tissues or organs, asymmetrical, sessile, body with water canals, diffusion for gas exchange
\.What supports the structure of sponges?
Collagen, spongin protein, and crystalline spicules made of calcium or silica.
\.What symmetry and body forms do Cnidarians have?
Radial symmetry, polyp (sessile) or medusa (free-swimming) forms.
\.What unique cells do Cnidarians have?
,Tentacles with stinging cells called nematocysts.
\.How do Cnidarians exchange gases and excrete waste?
Through diffusion directly from cells.
\.What is dominant in Class Hydrozoa?
The polyp stage.
\.What defines Class Scyphozoa (true jellyfish)?
Medusa stage is dominant, polyp stage reduced or absent.
\.What is unique about Class Anthozoa?
They exist only as polyps and include sea anemones and corals.
\.What are the main characteristics of flatworms?
Flattened bodies, bilateral symmetry, incomplete digestive system, cephalization, gas exchange
through diffusion.
\.What are the three main classes of Platyhelminthes?
Class Turbellaria (e.g., planaria), Class Trematoda (flukes), Class Cestoda (tapeworms).
\.How do tapeworms obtain nutrients?
They lack a digestive tract and absorb nutrients directly from the host.
\.What distinguishes annelids from other worms?
Segmented bodies, bilateral symmetry, complete digestive system, closed circulatory system.
\.How do annelids perform gas exchange?
Through their skin.
\.Name two classes of Annelida and examples.
Class Hirudinea (leeches), Class Oligochaeta (earthworms).
\.What are examples of organisms in Phylum Mollusca?
Snails (Class Gastropoda), octopus (Class Cephalopoda), clams (Class Bivalvia).
\.What distinguishes Phylum Arthropoda?
Includes insects, arachnids, and crustaceans, with segmented bodies and exoskeletons.
, \.What is unique about Phylum Echinodermata?
They exhibit radial symmetry and include sea stars.
\.What is a defining feature of Phylum Chordata?
Presence of a notochord at some stage of development.
\.What are the main characteristics of Mollusca?
Open circulatory system, visceral mass with organ systems, mantle secreting shell, muscular
foot for locomotion, and well-developed head with sensory organs.
\.Name three classes within Mollusca and examples of each.
Gastropoda: Snails, slugs.
Cephalopoda: Octopi, squid, cuttlefish.
Bivalvia: Clams, oysters, mussels.
\.How do cephalopods move?
Jet propulsion using a siphon to expel water.
\.What is the movement style of nematodes, and why?
Whip-like motion due to only longitudinal muscles.
\,How does the digestive system of nematodes differ from flatworms?
Nematodes have a complete digestive system with a separate mouth and anus.
\.Give examples of nematodes and their significance.
Ascaris: Intestinal parasite in humans.
Filarial Worms: Cause diseases like elephantiasis.
Pinworms: Common intestinal parasites in the U.S.
\.What are the key features of arthropods?
Exoskeleton, jointed appendages, segmentation, bilateral symmetry, open circulation
\.Name and describe three subgroups of arthropods.
Crustacea: Crabs, lobsters; marine, hard exoskeleton.
Insecta: Ants, flies; three body parts, three pairs of legs.
