Invertebrates and Porifera: Sponges

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Questions and Answers

What method do earthworms use to exchange gases?

Through their mouth

Through their gills

Through their lungs

Through mucus-covered skin (correct)

Which of the following is a feature of all mollusks?

They all possess a radula

They all have an external shell

They all live in water

They have a mantle that may produce a shell (correct)

Which classification applies to snails and slugs?

Bivalves

Cephalopods

Annelids

Gastropods (correct)

How do bivalves primarily acquire food?

By filter feeding Signup and view all the answers

What system do cephalopods have that differentiates them from many other mollusks?

Closed circulatory system Signup and view all the answers

Which of the following structures is NOT associated with earthworms?

Mantle Signup and view all the answers

What distinguishes annelids from mollusks?

Annelids are segmented worms Signup and view all the answers

Which feature helps gastropods move?

Mucus trail Signup and view all the answers

What percentage of the animal kingdom consists of invertebrates?

97% Signup and view all the answers

Which of the following characteristics is NOT true for sponges?

They have a complex nervous system. Signup and view all the answers

What is the function of the nematocysts found in cnidarians?

To sting and capture prey. Signup and view all the answers

What characteristic is unique to arthropods?

They possess a hard exoskeleton. Signup and view all the answers

Which of the following correctly describes the life cycle of an insect that undergoes complete metamorphosis?

Egg, Larva, Pupa, Adult Signup and view all the answers

How do most sponges reproduce?

Through asexual budding and sexual reproduction. Signup and view all the answers

Which body part is not found in arachnids?

Antennae Signup and view all the answers

Which body form of cnidarians is typically free-swimming?

Medusa Signup and view all the answers

In which group do centipedes and millipedes belong?

Myriapods Signup and view all the answers

What determines the classification of sponges into different classes?

The type of spicule they have. Signup and view all the answers

Which term best describes how sponges obtain food?

By filtering water via pores. Signup and view all the answers

How many pairs of legs do arachnids have?

Four Signup and view all the answers

What is the main function of the hard, spiny covering of a starfish?

Protection Signup and view all the answers

What is the primary method by which polyps of cnidarians reproduce asexually?

Budding Signup and view all the answers

Which statement about crustaceans is true?

They typically possess two pairs of antennae. Signup and view all the answers

What is a key characteristic of insects that allows them to thrive in diverse environments?

Three-part body structure. Signup and view all the answers

What characteristic is shared by both sea anemones and hydras?

They spend their entire life as polyps. Signup and view all the answers

Which feature distinguishes roundworms from flatworms?

Rounded bodies with a digestive tract that has both a mouth and an anus. Signup and view all the answers

How do jellyfish primarily reproduce?

Sexually to produce polyps. Signup and view all the answers

What is true about segmented worms?

Each segment possesses independent organs. Signup and view all the answers

What is a defining characteristic of flatworms like planaria?

They have a head and tail with bilateral symmetry. Signup and view all the answers

Which of the following is a common characteristic of earthworms?

They have more than 100 body segments. Signup and view all the answers

What distinguishes the feeding habits of nematodes like heartworm from other types of worms?

They can be decomposers, predators, or parasites. Signup and view all the answers

What is a notable fact about sea anemones?

They have soft tube-like bodies with tentacles. Signup and view all the answers

Study Notes

Invertebrates

Invertebrates are animals without backbones.
97% of the animal kingdom consists of invertebrates.
They live in various environments, including ponds, oceans, and other water sources.
Some invertebrates have exoskeletons, which are hard outer coverings that protect the animal's body and provide shape.

Porifera: Sponges

Sponges live in water; most are found in the ocean.
They resemble plants but are animals.
Sponges are sessile, meaning they remain fixed in one place.
Their bodies have many pores, and their skeletons are made of spiky fibers (spicules) or rubbery spongin.
Sponges are categorized by the type of spicule they possess; there are approximately 5,000 identified species.
Water flows through sponge pores, aided by flagella, which helps them capture food.
Sponges reproduce asexually through budding or gemules. Gemules are structures that allow a new sponge to grow from pieces of an established one.
Most sponges that reproduce sexually are hermaphrodites.
Sperm released into water flows into another sponge, where fertilization occurs, enabling larva development inside the sponge.
The larva is released and settles at the bottom, eventually growing into an adult sponge.

Cnidaria: Corals, Hydras, and Jellyfish

The name Cnidaria originates from the Greek word for nettle.
All cnidarians have stinging cells called nematocysts in their tentacles, which surround their mouths.
Cnidarians are more complex than sponges, possessing complex tissues, a digestive tract, and a nervous system.
They exist in two forms: polyp and medusa.
Polyps are typically sessile and vase-shaped.
Medusae are free-swimming and bell-shaped.
Cnidarians reproduce both asexually (budding) and sexually.

Sea Anemones and Corals

Sea anemones and corals are polyps throughout their entire life cycle.
They look similar to brightly colored flowers.
They live in colonies.
Their bodies are soft and tube-like, with a single opening and numerous tentacles.

Hydras

Hydras inhabit freshwater environments.
They remain in the polyp stage throughout their life cycle.
Hydras feature tentacles for capturing food.
They are mobile.
Hydras are small animals.
They reproduce asexually through budding.

Jellyfish

Jellyfish predominantly exist as medusae throughout their lives.
They swim freely in the water.
Jellyfish catch smaller animals (like shrimp, fish) using their tentacles.
Reproduction is a two-stage process: they first reproduce sexually to create polyps, and then asexually to produce new medusae.

Platyhelminthes: Flatworms

Flatworms are characterized by their flattened bodies, presence of a head and tail, and bilateral symmetry.
Flatworms search for food using their long, flattened bodies.
Some flatworms are free-living, such as Planaria.
Tapeworms are parasitic flatworms.
Each segment of a tapeworm (proglottid) contains reproductive organs, and when fertilized eggs fill a segment, it detaches and exits the host's waste.
Tapeworms can contain tens of thousands of eggs in a single segment.
They lack a digestive system, obtaining nutrients from the host's intestines.

Nematoda: Roundworms

Roundworms have rounded, tube-like bodies.
Their digestive tract has both a mouth and an anus.
They live in damp environments or inside humans and other animals.
Some roundworms are heartworms, passed to their host through mosquito bites.
They can also cause other illnesses to both humans and other animals.
Roundworms can be decomposer worms, predatory worms, or parasitic worms.
There are billions of roundworms in just one acre of soil.

Annelida: Segmented Worms

Annelids include earthworms, leeches, and marine worms.
Their bodies are divided into repeating segments.
Each segment contains nerve cells, blood vessels, and part of their digestive tract.
They have a closed circulatory system and a complete digestive system with two openings.
Earthworms have more than 100 body segments and use external bristles (setae) and muscles for locomotion.
They consume organic matter in the soil.
They exchange gases (CO2 and O2) through their mucus-covered skin.

Mollusca: Snails, Slugs, Clams, and Squid

Mollusks possess a soft body often covered in a hard shell.
They have a rough tongue called a radula and a muscular foot, as well as a mantle that produces the shell.
Aquatic mollusks use gills for gas exchange, while land mollusks have lungs.
Snails have one shell, while clams have two shells held together by a hinge.

Gastropod Mollusks: Slugs and Snails

Most gastropods have one shell.
They live in water or on land.
Gastropods move by gliding their muscular feet along a mucus trail.

Bivalve Mollusks: Clams and Other Two-Shelled Shellfish

Bivalves have two shells.
Large muscles open and close the halves of the two shells.
Bivalves are water animals that filter feed.
They use gills to remove food from water.

Cephalopod Mollusks: Octopus and Squid

Cephalopods lack an external shell.
Their foot is divided into tentacles with suckers.
They move by squeezing water through a funnel-like siphon.
They have a closed circulatory system with blood vessels.

Arthropoda: Insects, Spiders, Millipedes, and Crustaceans

Arthropods are invertebrates with jointed appendages (like legs and claws), antennae, and a hard exoskeleton.
They have bilateral symmetry.
There are over a million species of arthropods.
Arthropods molt, or shed their exoskeleton, as they grow, allowing their bodies to continue growing.

Insects: Characteristics and Metamorphosis

Insects have three body parts: head, thorax, and abdomen.
The head has antennae and eyes.
The thorax has legs and wings.
Reproductive organs are located in the abdomen.
Insects have an open circulatory system.
Oxygen enters through the insect's body.
Insects can undergo complete metamorphosis (egg, larva, pupa, adult), or incomplete metamorphosis (egg, nymph, adult).

Arachnids: Spiders, Scorpions, Ticks, and Mites

Arachnids have two main body parts: a cephalothorax and an abdomen.
The thorax has four pairs of jointed legs; arachnids do not have antennae.
Arachnids have special mouthparts, such as fangs.
Spiders kill more insect pests than any other animal.

Myriapods: Centipedes and Millipedes

Centipedes use their many legs to run away from enemies.
They have one pair of jointed legs on each segment.
Centipedes are predators.
Millipedes have two pairs of jointed legs on each segment.
Millipedes roll up their bodies when threatened.
They are herbivores.

Crustaceans: Shrimp, Crabs, Crayfish, and Lobsters

Crustaceans are mostly aquatic (in water) and have gills.
They have two pairs of antennae, three types of chewing appendages, and five pairs of legs.

Echinodermata: Starfish and Sea Urchins

Echinoderms have tiny tube feet and body parts arranged around a central area.
Starfish have five arms but no head.
The hard, spiny covering of starfish and sea urchins provides protection.
Sea urchins have spines covering their bodies.
Echinoderms exhibit radial symmetry.
They can be filter feeders, predators, or eat rotting materials.
They have a water vascular system for movement and consumption of food.
Some echinoderms can reproduce by regeneration from lost body parts.

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Description

Explore the fascinating world of invertebrates, which make up a significant portion of the animal kingdom. This quiz focuses on sponges, their unique characteristics, habitats, and reproductive methods. Dive into the details of this intriguing class of animals!