Diversity of Animals

<p>They lack defined tissue organization. (B)</p> Signup and view all the answers

<p>Multicellular organization (B)</p> Signup and view all the answers

<p>Pattern of embryonic development (B)</p> Signup and view all the answers

<p>Asymmetrical (A)</p> Signup and view all the answers

<p>Metazoans (C)</p> Signup and view all the answers

<p>Asymmetry (C)</p> Signup and view all the answers

<p>Can be divided into mirror-image halves (D)</p> Signup and view all the answers

<p>Protostomes (B)</p> Signup and view all the answers

<p>Their internal organs can evolve more complex shapes. (C)</p> Signup and view all the answers

<p>It allows for independent movement of internal organs. (D)</p> Signup and view all the answers

<p>Concentration of nervous tissue at one end (B)</p> Signup and view all the answers

<p>The division of body plans into repetitive segments (A)</p> Signup and view all the answers

<p>Earthworms (B)</p> Signup and view all the answers

<p>Radial symmetry (C)</p> Signup and view all the answers

<p>It aids in gas exchange through diffusion. (D)</p> Signup and view all the answers

<p>Cnidocyte (D)</p> Signup and view all the answers

<p>They exhibit bilateral symmetry. (C)</p> Signup and view all the answers

<p>They rely on diffusion for gas exchange. (B)</p> Signup and view all the answers

<p>Internal fertilization (B)</p> Signup and view all the answers

<p>They provide habitat for commercially fished species. (C)</p> Signup and view all the answers

<p>They possess a complete digestive system. (C)</p> Signup and view all the answers

<p>Independent segment movement (C)</p> Signup and view all the answers

<p>Internal skeleton composed of collagen and siliceous structures (D)</p> Signup and view all the answers

<p>No definite symmetry (B)</p> Signup and view all the answers

<p>Expansion and reorganization of the brain (C)</p> Signup and view all the answers

<p>Choanocytes (C)</p> Signup and view all the answers

<p>They encompass more than 9,000 species. (C)</p> Signup and view all the answers

<p>From legged gaits to specialized locomotion like bipedalism (D)</p> Signup and view all the answers

<p>They remove excess nitrogen from the environment. (C)</p> Signup and view all the answers

Organisms that lack defined tissues and organs. Cells are specialized but not organized into tissues.

Animals with defined tissues and organs. They have a higher level of organization.

Animals that exhibit no symmetry, meaning they lack any plane of division that creates mirror images.

Animals that can be divided into equal halves along multiple planes passing through a central axis.

Animals that can be divided into equal halves along only one plane, resulting in distinct left and right sides.

Animals without a body cavity. Their internal space is filled with tissue.

Animals with a body cavity that is not entirely lined by mesoderm.

Animals with a body cavity that is fully lined by mesoderm.

A digestive system with a single opening serving as both mouth and anus. Example: Flatworms.

A digestive system with separate openings for mouth and anus. Example: Humans.

A fluid-filled body cavity that provides structure and protection for internal organs. Example: Earthworms.

The evolutionary trend of concentrating nervous tissue at one end of an organism, forming a head with sensory organs. Example: Cephalopods

Segmentation allows for specialized sections of an organism, enabling redundancy of organ systems and efficient, independent movement for each segment.

The evolution of neurons in metazoans enabled electrical signaling. This led to the development of more complex nervous structures in later animals.

The development of ciliated epithelia, contractile muscles, and a more complex nerve net occurred as animals transitioned to a mobile lifestyle and larger food sources.

The internal skeleton of sponges is composed of collagen and siliceous structures.

Sponges are sessile, lacking a nervous system, and mainly aquatic filter feeders.

Sponges have a collection of specialized cells like choanocytes, pinacocytes, amoebocytes, and lophocytes, loosely arranged in a gelatinous matrix called mesohyl or mesenchyme.

Sponges play a crucial role in the nutrient cycle of coral reefs by removing excess nitrogen. They are also used in various industries for their skeleton's unique properties.

Cnidarians, including corals, hydras, jellyfish, and sea anemones, are characterized by their radial symmetry, specialized cells for stinging (nematocysts), and a generally marine lifestyle.

Cnidarians have radial symmetry, where body parts radiate from a central mouth, resembling a wheel or star.

Cnidarians have a gastrovascular cavity (GVC) that functions in digestion, excretion, and respiration. Food enters and waste exits through the same opening.

Cnidarians have specialized stinging cells called cnidocytes that contain nematocysts, which are stinging capsules.

Cnidarians lack internal organs such as a heart, brain, or lungs. Digestion occurs inside the gastrovascular cavity, nutrients are distributed by cells, and gas exchange is through diffusion.

Flatworms are triploblastic, have bilateral symmetry, and are acoelomate (lacking a body cavity) They have a single internal space, the digestive cavity.

Flatworms have a nervous system with ganglia and nerve cords. They have a simple excretory system with flame cells.

Flatworms lack specialized respiratory, circulatory, and skeletal systems.

Flatworms are monoecious (hermaphroditic) and have well-developed reproductive systems. They reproduce internally, and their development can be direct or involve multiple hosts.