Q1. Which of the following phyla includes organisms characterized by radial symmetry and often possess tentacles armed with stinging cells?
a) Porifera
b) Cnidaria
c) Platyhelminthes
d) Annelida
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Correct Answer: b) Cnidaria
Explanation: Cnidarians, such as jellyfish and corals, exhibit radial symmetry and possess specialized stinging cells called cnidocytes. These organisms typically have tentacles surrounding a central mouth, used for feeding and defense.
Q2. Organisms belonging to the phylum Porifera are commonly known as:
a) Flatworms
b) Sponges
c) Roundworms
d) Cnidarians
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Correct Answer: b) Sponges
Explanation: Porifera is the phylum of sponges, which are multicellular organisms characterized by a porous body structure. Sponges are filter feeders, drawing in water through pores and capturing food particles within their bodies.
Q3. Which phylum includes organisms known for their segmented bodies and bristly appendages called setae?
a) Arthropoda
b) Mollusca
c) Echinodermata
d) Chordata
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Correct Answer: a) Arthropoda
Explanation: Arthropods, such as insects, spiders, and crustaceans, are characterized by their segmented bodies, jointed appendages, and exoskeletons made of chitin. Many arthropods also possess specialized structures called setae for locomotion and sensory functions.
Q4. The phylum Mollusca includes organisms with which of the following features?
a) Segmented bodies and jointed appendages
b) Radial symmetry and tentacles
c) Soft bodies and often possess a hard shell
d) Spiny skin and water vascular system
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Correct Answer: c) Soft bodies and often possess a hard shell
Explanation: Mollusks are soft-bodied animals that often possess a hard external shell for protection. Examples of mollusks include snails, clams, octopuses, and squids.
Q5. Which of the following phyla is characterized by organisms with a segmented body and a notochord at some stage of their development?
a) Annelida
b) Cnidaria
c) Echinodermata
d) Chordata
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Correct Answer: d) Chordata
Explanation: Chordates are characterized by the presence of a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some stage of their development. This phylum includes vertebrates and some invertebrate groups.
Q6. Members of the phylum Echinodermata are characterized by which of the following features?
a) Segmented bodies and jointed appendages
b) Exoskeleton made of chitin
c) Radial symmetry and a water vascular system
d) Soft bodies and often possess a hard shell
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Correct Answer: c) Radial symmetry and a water vascular system
Explanation: Echinoderms, such as starfish and sea urchins, exhibit radial symmetry and possess a unique water vascular system used for locomotion, feeding, and gas exchange.
Q7. Organisms belonging to the phylum Platyhelminthes are commonly known as:
a) Roundworms
b) Flatworms
c) Segmented worms
d) Bivalves
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Correct Answer: b) Flatworms
Explanation: Platyhelminthes, or flatworms, are a group of bilaterally symmetric organisms with flat, ribbon-like bodies. They include parasitic flatworms like tapeworms and free-living flatworms like planarians.
Q8. The phylum Nematoda includes organisms commonly known as:
a) Roundworms
b) Flatworms
c) Segmented worms
d) Bivalves
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Correct Answer: a) Roundworms
Explanation: Nematodes, or roundworms, are unsegmented worms with cylindrical bodies. They are found in diverse habitats, including soil, water, and as parasites of plants and animals.
Q9. Members of the phylum Annelida are characterized by which of the following features?
a) Segmented bodies and jointed appendages
b) Radial symmetry and tentacles
c) Soft bodies and often possess a hard shell
d) Metamorphosis and a notochord
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Correct Answer: a) Segmented bodies and jointed appendages
Explanation: Annelids are segmented worms with bodies composed of repeating units called segments. They often possess bristly appendages called setae for locomotion and sensory functions.
Q10. The phylum Arthropoda includes organisms characterized by which of the following features?
a) Soft bodies and often possess a hard shell
b) Radial symmetry and a water vascular system
c) Segmented bodies and jointed appendages
d) Metamorphosis and a notochord
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Correct Answer: c) Segmented bodies and jointed appendages
Explanation: Arthropods are characterized by their segmented bodies, jointed appendages, and exoskeletons made of chitin. This diverse phylum includes insects, arachnids, crustaceans, and myriapods.