Biology Test 3 Flashcards

Questions and Answers

What are Cnidocytes?

Specialized stinging cells found in Cnidarians, used for defense and catching prey.

What differentiates Polyps and Medusas?

Polyps adhere to a surface at the base and have a gastrovascular top; Medusas have a bell-shaped body, are free-moving, and have their gastrovascular cavity on the bottom.

Describe how a sponge feeds and digests its food.

A sponge catches its food by moving water through the pores and out the Osculum. It's digested by being engulfed in mucus in the pores.

List the characteristics of the phylum Cnidaria that distinguish it from other animal phyla.

They have a gastrovascular cavity, Cnidocytes, forms include Polyps and Medusa, and can be sessile or mobile. Signup and view all the answers

List the four classes of Cnidaria and distinguish among them based on life cycle morphology.

Anthozoa: only polyps, hard exoskeleton; Hydrozoa: reproduce by budding; Scyphozoa: has round medusa and radial symmetry; Cubozoa: box-shaped, hollow tentacles. Signup and view all the answers

List the characteristics of Platyhelminthes and distinguish among the four classes.

Gas exchange happens on the surface, protonephridia regulates osmotic balance, they are very flat; classes include Monogenea (parasitic on gills, no coelom), Turbellaria (no respiratory or circulatory system), Trematoda (parasitic, small, take hosts on land), Cestoda (segmented). Signup and view all the answers

Describe the features of molluscs and distinguish among the four classes.

Soft-bodied, most have shells; classes include Polyplacophora (chitons, 8 dorsal plates), Gastropoda (spiraled shell, use foot or cilia for motion), Bivalves (2 halves drawn together by adductor muscles), Cephalopods (have a beak, use tentacles). Signup and view all the answers

Describe the features of annelids and distinguish among the three classes.

Coelomates with bodies composed of fused rings; classes include Polychaete (mobile marine, feet on each segment), Oligochaeta (less mobile, burrow or live in tubes), Hirudinea (leeches, predatory, suck blood). Signup and view all the answers

List the characteristics of nematodes that distinguish them from other wormlike animals.

Have an alimentary canal but have no circulatory system. Signup and view all the answers

List three features that account for the success of arthropods.

Segmented body, flight, legs on either side of segments. Signup and view all the answers

Define and distinguish among the three major arthropod lineages.

Chelicerates: have claw-like appendages called chelicerae and book lungs (includes arachnids); Myriapods: terrestrial with jaw-like mandibles; Pancrustaceans: includes insects and crustaceans. Signup and view all the answers

Describe the developmental similarities between echinoderms and chordates.

Both constitute the clade Deuterostomia; Echinoderms have radial symmetry, a slow-moving water vascular system, and tube feet; Chordates have bilateral symmetry with a segmented body. Signup and view all the answers

What are the characteristics of the Phylum Cnidaria that distinguish it from other animals?

They have a gastrovascular cavity, Cnidocytes, forms include Polyp and Medusa, and can be sessile or mobile. Signup and view all the answers

What is a coelomate?

Animals that have a fluid-filled body cavity called a coelom, with a complete lining called a peritoneum. Signup and view all the answers

The animals of the clade Errantia have a pair of paddle-like structures called...?

Parapodia. Signup and view all the answers

The bristles on parapodia are called what? And what are they made of?

The bristles are called Chaetae, and they are made of Chitin. Signup and view all the answers

What chemicals do Leeches secrete and what is it used for?

They secrete HIRUDIN, which prevents blood from coagulation. Signup and view all the answers

Which Clade is most species rich?

Ecdysoans. Signup and view all the answers

What are cuticles made of and through what process are they shed?

The cuticle is made of a protein called Chitin, and it is shed through Ecdysis. Signup and view all the answers

What are the three major lineages of the phylum Arthropoda?

Chelicerates, Myriapods, Pancrustaceans. Signup and view all the answers

What is Hemolymph?

A fluid equivalent to blood in Invertebrates. Signup and view all the answers

Most of the Clade Chelicerata are extinct.

True Signup and view all the answers

Arachnids have what kind of respiratory system?

They have book lungs. Signup and view all the answers

What is silk?

A liquid protein produced from specialized abdominal glands. Signup and view all the answers

What are mandibles?

Pincers on the front of Myriapods. Signup and view all the answers

What are the young of Complete Metamorphosis called and what do they look like?

They are called larvae, such as maggots, grubs, and caterpillars; they look very different from the adults. Signup and view all the answers

What are the young of incomplete metamorphosis called and what do they look like?

The young are called Nymphs and they resemble the adults but are smaller. Signup and view all the answers

Sea Stars have a unique vascular system that attaches to tube feet for what two purposes?

They have a water vascular system; their tube feet are used for motion and feeding. Signup and view all the answers

What is the life cycle of a Blood Fluke?

<ol> <li>Mature ones live in blood vessels of human intestines; 2) They reproduce sexually and the eggs exit through human poop; 3) Eggs develop into ciliated larvae in water and infect snails; 4) Asexual reproduction in snails leads to new motile larvae; 5) Larvae penetrate skin and blood vessels of humans in irrigated fields contaminated with infected human poop.</li> </ol> Signup and view all the answers

What are the two body types of Cnidarians?

Polyps and Medusa. Signup and view all the answers

What distinguishes the Clade Eumetzoa?

They are the 'true tissue' animals. Signup and view all the answers

What is a Spongocoel and what is an Osculum?

Spongocoels are pore-like openings that allow water and food to enter the inner cavity of the sponge; Osculum is the opening at the top of the sponge where water exits. Signup and view all the answers

Sponges are suspension feeders. What does this mean?

They capture food particles that are suspended in water as it passes through their body. Signup and view all the answers

Which Phyla are classified as Deuterostomia?

Echinodermata (Sea Urchins) and Chordata (Tunicates). Signup and view all the answers

Which Phyla are classified as Ecdysozoans?

Nematoda (Round worms) and Arthropoda (Scorpions, arachnids). Signup and view all the answers

Which Phyla are classified as Lophotrochozoans?

Rotifera (Rotifers), Mollusca (mollusks, octopi), Annelida (Annelids). Signup and view all the answers

What classifies an invertebrate?

Lack of a backbone. Signup and view all the answers

What percent of molluscs are Gastropods?

75% are gastropods. Signup and view all the answers

Which Phylum has the largest number of recent extinctions and what caused it?

Phylum Mollusca; causes include loss of habitat, pollution, and non-native species. Signup and view all the answers

Lophotrochozoans have what symmetry and what type of development?

Bilateral symmetry; they have triploblastic development. Signup and view all the answers

What are the two major clades of the phylum Cnidaria? What are their differences?

Medusozoa: alternate between polyp and medusa forms (includes Hydrozoa, Scyphozoa, and Cubozoa); Anthozoans: only occur as Polyps (include Corals and Anemones). Signup and view all the answers

What are Cnidocytes and what kind of animal has them?

They are specialized stinging cells used for protection and catching prey. Cnidarians have them. Signup and view all the answers

What kind of tissues do the clade Eumetzoa have?

They are 'true tissue' animals. Signup and view all the answers

Phylum Porifera (sponges) are what kind of feeders?

They are suspension feeders. Signup and view all the answers

What are the derived characteristics of Chordates?

They have a hollow nerve cord on their dorsal side, notochord, muscular post-anal tail, anus, pharyngeal slits or clefts, and muscle segments. Signup and view all the answers

Which two Chordates have only one cluster of Hox genes?

Lancelets and Tunicates. Signup and view all the answers

A skeletal system and complex nervous systems have allowed vertebrates efficiency at what two tasks?

Catching food and evading predators. Signup and view all the answers

What period are the fossils that show a transition into Craniates (animals with skulls)?

Cambrian Period. Signup and view all the answers

What is a Haikouella and what made it special?

It is the most primitive fossil found from the Cambrian period; it was about 3 cm long and had a well-formed brain, eyes, and muscular segments but no skull or ear organs. Signup and view all the answers

Vertebrates that didn't have jaws had what to protect them?

They had defensive plates of bone on their skin. Signup and view all the answers

Mineralization of skeletons most likely started with which part of a vertebrate?

Mouth parts. Signup and view all the answers

What is a Gnathostome?

Vertebrates that have jaws. Signup and view all the answers

The earliest gnathostomes were part of what extinct lineage, and when did they appear?

They are part of the Placoderms and they appeared around 440 million years ago. Signup and view all the answers

What group of jawed vertebrates appeared in the Silurian and Devonian periods?

Acanthodians. Signup and view all the answers

What are the three lineages of jawed vertebrates still around today?

Chondrichthyans, ray-finned fish, lobe-finned fish. Signup and view all the answers

What is the largest and most diverse group of Chondrichthyes?

Elasmobranchii (sharks and rays). Signup and view all the answers

What is the ridge in a shark's digestive tract called and what is its purpose?

It is a Spiral Valve, which increases surface area. Signup and view all the answers

What is a Cloaca?

A cavity in some vertebrates that reproductive fluids and poop empty into. Signup and view all the answers

What clade do the vast majority of vertebrates belong to?

Osteichthyes. Signup and view all the answers

What is the difference between Anatomy and Physiology?

Form vs Function. Signup and view all the answers

What is the greatest factor of an animal's shape?

Environment. Signup and view all the answers

Study Notes

Cnidocytes and Cnidaria

Cnidocytes are specialized stinging cells in Cnidarians, crucial for defense and prey capture.
Cnidaria exhibit two body forms: Polyp (sessile) and Medusa (free-moving).
Characteristics of Cnidaria: gastrovascular cavity, presence of Cnidocytes, and can be sessile or mobile.
Four classes of Cnidaria include:
- Anthozoa: only polyps with a hard exoskeleton.
- Hydrozoa: reproduce by budding.
- Scyphozoa: have a round medusa, exhibit radial symmetry.
- Cubozoa: box-shaped with hollow tentacles.

Sponges and Feeding

Sponges feed by moving water through their porous body and into the oscillator where food is digested in mucus.
Sponges are suspension feeders, capturing particles suspended in the water as it flows through their bodies.

Annelids and Nematodes

Annelids are coelomates with bodies of fused rings; classes include:
- Polychaete: mobile marine animals with feet on each segment.
- Oligochaeta: less mobile, living in burrows.
- Hirudinea: leeches that are bloodsuckers, secreting a chemical to prevent coagulation.
Nematodes have a complete alimentary canal but lack a circulatory system.

Arthropods and Their Success

Key features contributing to arthropod success include a segmented body, ability to fly, and legs attached to each segment.
Three major arthropod lineages:
- Chelicerates: have claw-like appendages (chelicerae) and book lungs, including arachnids.
- Myriapods: terrestrial with jaw-like mandibles.
- Pancrustaceans: includes insects and crustaceans.

Echinoderms and Chordates

Echinoderms and chordates share developmental similarities, both falling under the Deuterostomia clade.
Echinoderms possess radial symmetry and a water vascular system, while chordates have bilateral symmetry and segmented bodies.

Phylums and Their Characteristics

Invertebrates lack backbones; notable groups include:
- Deuterostomia: Echinoderma and Chordata.
- Ecdysozoans: Nematoda and Arthropoda.
- Lophotrochozoans: Rotifera, Mollusca, and Annelida.
Gastropods constitute 75% of mollusks.
Phylum Mollusca has faced significant recent extinctions due to habitat loss, pollution, and invasive species.

Chordates and Their Evolution

Derived characteristics of chordates:
- Hollow dorsal nerve cord, notochord, muscular post-anal tail, pharyngeal slits, anus, mouth, and muscle segments.
Early vertebrates developed defensive bony plates and lack of jaws identified as a key evolutionary trait.

Gnathostomes and Vertebrate Diversity

Gnathostomes are jawed vertebrates, with the earliest appearing around 440 million years ago.
Current jawed vertebrate lineages: Chondrichthyans (sharks/rays), ray-finned fish, and lobe-finned fish.

Specialized Structures in Vertebrates

Sharks have a spiral valve in their digestive tract to increase surface area.
Cloaca serves as a cavity for expelling reproductive fluids and waste in some vertebrates.

Comparative Anatomy and Physiology

Distinction between anatomy and physiology: anatomy refers to structure (form), whereas physiology refers to function.
An animal's shape is greatly influenced by its environment.

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Prepare for your Biology Test 3 with these comprehensive flashcards. Each card presents key terms and definitions related to Cnidarians and sponges, essential for understanding their unique biological traits and functions. Test your knowledge and enhance your study sessions efficiently.