Lab 3 Invertebrate Diversity and Anatomy

Flashcards summarizing key vocabulary and concepts related to invertebrate diversity and anatomy, including definitions of important terms and concepts.

Eumetazoa

A clade of animals that have true tissues.

Radial symmetry

Body plan in which any cut through the center produces two identical halves.

Bilateral symmetry

Body plan with a distinct left and right side; only one cut through the middle produces two identical halves.

Diploblastic

Organisms that develop from two embryonic germ layers: ectoderm and endoderm.

Triploblastic

Organisms that develop from three embryonic germ layers: ectoderm, mesoderm, and endoderm.

Acoelomate

An organism that has no body cavity (coelom) between the digestive cavity and outer body wall.

Coelomate

An organism that has a true coelom, a body cavity that is lined with mesoderm.

Cnidarians

Aquatic animals belonging to the phylum Cnidaria, characterized by radial symmetry and two germ layers. (polyps-sessile and medusa-motile)

Platyhelminthes

Phylum of flatworms that are acoelomate and have bilateral symmetry.

Mollusca

Phylum including soft-bodied animals like snails and octopuses, most of which have a calcium carbonate shell.

Annelida

Phylum of segmented worms, characterized by a coelom and metamerism (segmentation).

Ecdysozoa

Clade of animals that grow by molting their exoskeleton (ecdysis).

Arthropoda

Phylum of invertebrates that have jointed limbs and an exoskeleton.

Myriapoda

Subphylum of arthropods, includes centipedes and millipedes.

Crustacea

Subphylum of arthropods that includes crabs, lobsters, and shrimp.

Insecta

Subphylum of arthropods characterized by three pairs of legs and a body divided into three segments: head, thorax, abdomen.

Cephalization

The evolutionary trend of bringing the sense organs and nerve cells into a centralized area (head).

Tagmosis

The division of the body into distinct regions or tagma, each with specialized functions.

Nematocyst

A specialized cell in cnidarians containing a small harpoon-like structure for capturing prey.

Gastrovascular cavity

A central cavity in cnidarians that serves both digestive and circulatory functions.

Radula

A toothed, chitinous ribbon in mollusks used for scraping food.

Metamerism

The segmentation of the body into a series of repeated units.

List examples of animals with radial symmetry.

clade Eumetazoa, Cnidaria such as jellyfish and sea anemones.

What is coelomate development?

Coelomate development refers to animals within the clade Bilateria that possess a coelom, such as those in Lophotrochozoa (earthworms, mollusks) and Ecdysozoa (including Arthropoda, Myriapoda, Crustacea and Insecta), characterized by a body cavity fully lined by mesoderm.

Which have bilateral symmetry?

Those in the clade Bilateria which include all but Cnidara

What clade does Planaria belong to?

Planaria belongs to the clade Lophotrochozoa, which includes flatworms (Platyhelminthes).

What clade does the earthworm belong to?

The earthworm belongs to the clade Lophotrochoza, within the phylum Annelida.

What clade does the snail belong to?

The snail belongs to the clade Lophotrochoza, specifically within the phylum Mollusca.

What clade does the centipede belong to?

The centipede belongs to the clade Ecdysozoa, which encompasses Myriapoda.

What clade does the shrimp belong to?

The shrimp belongs to the clade Ecdysozoa, specifically within the subphylum Crustacea.

What clade does the locust belong to?

The locust belongs to the clade Ecdysozoa, under the class Insecta.

How many germ layers do Cnidaria have?

Cnidaria have two germ layers: ectoderm and endoderm.

How many germ layers do Planaria (Platyhelminthes) have?

Planaria (Platyhelminthes) have three germ layers: ectoderm, mesoderm, and endoderm.

How many germ layers do earthworms (Annelida) have?

Earthworms (Annelida) have three germ layers: ectoderm, mesoderm, and endoderm.

How many germ layers do snails (Mollusca) have?

Snails (Mollusca) have three germ layers: ectoderm, mesoderm, and endoderm.

How many germ layers do centipedes (Myriapoda) have?

Centipedes (Myriapoda) have three germ layers: ectoderm, mesoderm, and endoderm.

How many germ layers do shrimp (Crustacea) have?

Shrimp (Crustacea) have three germ layers: ectoderm, mesoderm, and endoderm.

How many germ layers do locusts (Insecta) have?

Locusts (Insecta) have three germ layers: ectoderm, mesoderm, and endoderm.

Do Cnidaria have a hard body covering like a shell?

No, Cnidaria do not have a hard body covering like a shell; they possess a soft body structure supported by a gelatinous mesoglea.

Do Planaria (Platyhelminthes) have a hard body covering like a shell?

No, Planaria (Platyhelminthes) do not have a hard body covering; they have a soft, flexible body covered by a ciliated epidermis.

Do earthworms (Annelida) have a hard body covering like a shell?

No, earthworms (Annelida) do not have a hard body covering; they have a soft, moist body covered by a cuticle.

Do snails (Mollusca) have a hard body covering like a shell?

Yes, snails (Mollusca) have a hard body covering, which is a shell made primarily of calcium carbonate.

Do centipedes (Myriapoda) have a hard body covering like a shell?

No, centipedes (Myriapoda) do not have a hard body covering like a shell; they have a segmented exoskeleton, but it is not shell-like.

Do shrimp (Crustacea) have a hard body covering like a shell?

Yes, shrimp (Crustacea) have a hard body covering that consists of an exoskeleton made of chitin, which can be shell-like in its rigidity.

Do locusts (Insecta) have a hard body covering like a shell?

No, locusts (Insecta) do not have a hard body covering like a shell; they have an exoskeleton that is tough but not shell-like.

Do Cnidaria show cephalisation?

No, Cnidaria do not show cephalisation; they have a radial symmetry and lack a defined head region.

Do Planaria (Platyhelminthes) show cephalisation?

Yes, Planaria (Platyhelminthes) show cephalisation; they have a distinct head with sensory organs and a concentration of nerve tissue.

Do earthworms (Annelida) show cephalisation?

Yes, earthworms (Annelida) show a degree of cephalisation; they have a defined head region with a concentration of nervous tissue and sensory organs.

Do snails (Mollusca) show cephalisation?

Yes, snails (Mollusca) show cephalisation; they have a distinct head with sensory organs and tentacles that aid in navigation and feeding.

Do centipedes (Myriapoda) show cephalisation?

Yes, centipedes (Myriapoda) show cephalisation; they have a well-defined head with sensory appendages and a concentration of nerve cells.

Do shrimp (Crustacea) show cephalisation?

Yes, shrimp (Crustacea) show cephalisation; they have a noticeable head region that houses sensory organs and a brain.

Do locusts (Insecta) show cephalisation?

Yes, locusts (Insecta) show cephalisation; they have a prominent head with well-developed sensory organs and a centralized nervous system.

Do Cnidaria have a coelomic cavity?

No, Cnidaria do not have a coelomic cavity; they are acoelomate and have a simple body structure with a gastrovascular cavity.

Do Planaria (Platyhelminthes) have a coelomic cavity?

No, Planaria (Platyhelminthes) do not have a true coelomic cavity; they are acoelomate and lacking a body cavity between the digestive tract and body wall.

Do earthworms (Annelida) have a coelomic cavity?

Yes, earthworms (Annelida) possess a true coelomic cavity, which serves as a hydrostatic skeleton and allows for organ development.

Do snails (Mollusca) have a coelomic cavity?

Yes, snails (Mollusca) have a true coelomic cavity, although it is reduced and primarily surrounds the heart and gonads.

Do centipedes (Myriapoda) have a coelomic cavity?

Yes, centipedes (Myriapoda) have a coelomic cavity, although it is not well-defined compared to other taxa.

Do shrimp (Crustacea) have a coelomic cavity?

Yes, shrimp (Crustacea) have a true coelomic cavity, which is reduced and primarily houses the heart and reproductive organs.

Do locusts (Insecta) have a coelomic cavity?

Yes, locusts (Insecta) have a coelomic cavity, although it is reduced; they have a hemocoel that serves as the main body cavity in arthropods.

Do Cnidaria have a gastrovascular cavity or alimentary canal as a digestive tract?

Cnidaria have a gastrovascular cavity, which functions in both digestion and nutrient distribution.

Do Planaria (Platyhelminthes) have a gastrovascular cavity or alimentary canal as a digestive tract?

Planaria (Platyhelminthes) have a gastrovascular cavity that serves as a digestive tract with one opening.

Do earthworms (Annelida) have a gastrovascular cavity or alimentary canal as a digestive tract?

Earthworms (Annelida) have an alimentary canal, a complete digestive system with a mouth and an anus.

Do snails (Mollusca) have a gastrovascular cavity or alimentary canal as a digestive tract?

Snails (Mollusca) have an alimentary canal, allowing for a more complex digestive system with specialized regions for processing food.

Do centipedes (Myriapoda) have a gastrovascular cavity or alimentary canal as a digestive tract?

Centipedes (Myriapoda) have an alimentary canal, which allows for efficient digestion and nutrient absorption.

Do shrimp (Crustacea) have a gastrovascular cavity or alimentary canal as a digestive tract?

Shrimp (Crustacea) have an alimentary canal that features a complete digestive system adapted for processing various foods.

Do locusts (Insecta) have a gastrovascular cavity or alimentary canal as a digestive tract?

Locusts (Insecta) have an alimentary canal, which includes specialized regions for digestion and nutrient absorption.

Do Cnidaria display metamerism?

No, Cnidaria do not display metamerism; they have a simple body plan without segmented structures.

Do Planaria (Platyhelminthes) display metamerism?

No, Planaria (Platyhelminthes) do not display metamerism; they are acoelomate and do not have a segmented body.

Do earthworms (Annelida) display metamerism?

Yes, earthworms (Annelida) display metamerism; their bodies are segmented, allowing for specialized functions in each segment.

Do snails (Mollusca) display metamerism?

No, snails (Mollusca) do not display metamerism; they have a unsegmented body plan without visible segmentation.

Do centipedes (Myriapoda) display metamerism?

Yes, centipedes (Myriapoda) display metamerism; their bodies consist of multiple segments, each with a pair of legs.

Do shrimp (Crustacea) display metamerism?

Yes, shrimp (Crustacea) display a form of metamerism, as their bodies are segmented into distinct regions like the cephalothorax and abdomen.

Do locusts (Insecta) display metamerism?

Yes, locusts (Insecta) display metamerism; their bodies are segmented into distinct regions including the head, thorax, and abdomen.

Do Cnidaria display tagmosis?

No, Cnidaria do not exhibit tagmosis; their body structure is not organized into specialized regions or segments.

Do Planaria (Platyhelminthes) display tagmosis?

Yes, Planaria (Platyhelminthes) demonstrate simple tagmosis, characterized by minimal specialization with a basic head and body region.

Do earthworms (Annelida) display tagmosis?

No, earthworms (Annelida) do not exhibit tagmosis; their body segments are uniform and lack distinct specialized regions.

Do snails (Mollusca) display tagmosis?

No, snails (Mollusca) do not show tagmosis; their body plan is not divided into specialized functional regions.

Do centipedes (Myriapoda) display tagmosis?

Yes, centipedes (Myriapoda) exhibit tagmosis, with a clear division into a head region and a segmented trunk.

Do shrimp (Crustacea) display tagmosis?

Yes, shrimp (Crustacea) display tagmosis, having distinct body regions such as the cephalothorax and abdomen that serve specific functions.

Do locusts (Insecta) display tagmosis?

Yes, locusts (Insecta) show tagmosis through their distinct body regions: head, thorax, and abdomen that fulfill specialized roles.

What distinguishes Eumetazoa?

Eumetazoa are characterized by having true tissues, organized into distinct layers (ectoderm, mesoderm, endoderm), and exhibit bilateral or radial symmetry.

What are the key characteristics of Cnidaria?

Cnidaria are distinguished by their radial symmetry, presence of cnidocytes (stinging cells), and a body plan consisting of a polyp or medusa form.

What defines Bilateria?

Bilateria are characterized by bilateral symmetry, a distinct head region (cephalization), and typically exhibit three germ layers (ectoderm, mesoderm, endoderm).

What are the main features of Lophotrochozoa?

Lophotrochozoa are characterized by having a lophophore feeding structure or a trochophore larval stage; this group includes diverse animals such as annelids and mollusks.

What distinguishes Platyhelminthes?

Platyhelminthes (flatworms) are acoelomate, bilaterally symmetrical, and have a flattened body structure lacking specialized respiratory and circulatory systems.

What are the characteristics of Mollusca?

Mollusca are characterized by a coelom, a segmented body plan with a muscular foot, a visceral mass, and typically a calcium carbonate shell.

What defines Annelida?

Triploblastic bilaterian coelomates. Leeches and earthworms

What distinguishes Ecdysozoa?

Ecdysozoa are characterized by the presence of a cuticle that is molted or shed (ecdysis) during growth, including groups such as arthropods and nematodes.

What are the key features of Arthropoda?

Arthropoda are characterized by an exoskeleton made of chitin, jointed appendages, and a segmented body divided into distinct regions (head, thorax, abdomen).

What distinguishes Myriapoda?

Myriapoda are characterized by having numerous body segments, each with one or two pairs of legs, and include millipedes and centipedes.

What are the main features of Crustacea?

Crustacea are distinguished by having a chitinous exoskeleton, two pairs of antennae, and typically a division of the body into a cephalothorax and abdomen.

What defines Insecta?

Insecta are characterized by having three main body parts (head, thorax, abdomen), three pairs of legs, and usually one or two pairs of wings.

What are cnidocytes?

Cnidocytes are specialized cells found in Cnidaria, containing nematocysts (stinging structures) used for defense and capturing prey.

What does the phylum Platyhelminthes include?

The phylum Platyhelminthes includes free-living species (turbellarians) and parasitic forms such as flukes (Trematoda) and tapeworms (Cestoda).

What is the pharynx in planarians?

The pharynx in planarians is a muscular tube that can extend out of the body to suck in food and is often located mid-ventrally.

What is the function of the ciliated epidermis in planarians?

The ciliated epidermis in planarians aids in movement and locomotion by allowing for gliding over surfaces through coordinated ciliary beating.

What are dorsoventral muscles in planarians?

Dorsoventral muscles in planarians run from the dorsal to the ventral side and assist in flattening and bending the body for movement.

What are diverticula in the digestive system of planarians?

Diverticula are branches of the intestine in planarians that increase the surface area for nutrient absorption and distribution throughout the body.