1. Question: Explain the classification of animals based on their body symmetry and provide examples for each type.
Answer: Animals can be classified into three categories based on their body symmetry: radial symmetry, bilateral symmetry, and asymmetry. Radially symmetrical animals, such as jellyfish, have body parts arranged around a central axis. Bilaterally symmetrical animals, such as humans, have a distinct right and left side that mirror each other. Asymmetrical animals, such as sponges, lack any specific symmetry.
2. Question: Discuss the characteristics and examples of animals belonging to the phylum Porifera.
Answer: Porifera, commonly known as sponges, are multicellular organisms that lack true tissues and organs. They have a porous body structure with numerous tiny pores called ostia. Sponges obtain food by filter feeding and have specialized cells called choanocytes that help in capturing food particles. Examples of Porifera include the common bath sponge (Spongilla) and the barrel sponge (Xestospongia).
3. Question: Describe the distinguishing features and examples of animals belonging to the phylum Cnidaria.
Answer: Cnidaria includes animals like jellyfish, sea anemones, and coral. They possess specialized cells called cnidocytes that contain stinging structures called nematocysts. These nematocysts are used for capturing prey and defense. Cnidarians exhibit radial symmetry and have a sac-like body plan with a central digestive cavity called the gastrovascular cavity.
4. Question: Explain the characteristics and examples of animals belonging to the phylum Platyhelminthes.
Answer: Platyhelminthes, also known as flatworms, are soft-bodied, bilaterally symmetrical animals. They have a flattened body shape and lack a body cavity. Flatworms exhibit various adaptations such as cephalization (concentration of sensory organs in the head region) and regeneration ability. Examples of Platyhelminthes include tapeworms, planarians, and flukes.
5. Question: Discuss the characteristics and examples of animals belonging to the phylum Annelida.
Answer: Annelids are segmented worms that exhibit bilateral symmetry and have a true body cavity called a coelom. They possess numerous segments along their body, which aids in locomotion. Annelids have a closed circulatory system and a well-developed nervous system. Examples of Annelida include earthworms, leeches, and marine polychaetes.
6. Question: Describe the distinguishing features and examples of animals belonging to the phylum Mollusca.
Answer: Mollusca includes animals like snails, clams, and octopuses. They have a soft body, often protected by a hard shell. Mollusks exhibit bilateral symmetry and possess a muscular foot for locomotion. They also have a specialized feeding structure called a radula. Mollusks have a well-developed circulatory system and a mantle that secretes the shell.
7. Question: Explain the characteristics and examples of animals belonging to the phylum Arthropoda.
Answer: Arthropods are the largest phylum in the animal kingdom and include insects, spiders, crustaceans, and millipedes. They have a segmented body, jointed appendages, and an exoskeleton made of chitin. Arthropods exhibit bilateral symmetry and have specialized respiratory structures such as tracheae or gills. They also possess compound eyes and undergo metamorphosis during their life cycle.
8. Question: Discuss the distinguishing features and examples of animals belonging to the phylum Echinodermata.
Answer: Echinoderms, such as starfish, sea urchins, and sea cucumbers, exhibit radial symmetry as adults. They have a unique water vascular system that aids in locomotion, feeding, and gas exchange. Echinoderms possess a calcareous endoskeleton and tube feet for movement. They also have the ability to regenerate lost body parts.
9. Question: Describe the characteristics and examples of animals belonging to the phylum Chordata.
Answer: Chordates are characterized by the presence of a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some point in their life cycle. They exhibit bilateral symmetry and possess a well-developed endoskeleton. Chordates are divided into three subphyla: Urochordata (tunicates), Cephalochordata (lancelets), and Vertebrata (vertebrates).
10. Question: Explain the distinguishing features and examples of animals belonging to the subphylum Vertebrata.
Answer: Vertebrates are chordates that possess a vertebral column, which provides structural support and protects the spinal cord. They exhibit bilateral symmetry and have a well-developed nervous system. Vertebrates also possess complex organ systems, including a closed circulatory system and a well-developed brain. Examples of vertebrates include fishes, amphibians, reptiles, birds, and mammals.