- What is the primary characteristic of sponges in the class Calcarea?
- A) They have siliceous spicules.
- B) They have calcium carbonate spicules.
- C) They lack spicules.
- D) They have organic spicules.
- Answer: B) They have calcium carbonate spicules.
- Which of the following habitats do Calcarea sponges primarily occupy?
- A) Freshwater
- B) Marine
- C) Terrestrial
- D) Brackish water
- Answer: B) Marine.
- What type of body plan is commonly found in Calcarea sponges?
- A) Asconoid
- B) Syconoid
- C) Leuconoid
- D) Both A and B
- Answer: D) Both A and B.
- What is the main composition of the spicules in Calcarea sponges?
- A) Silica
- B) Calcium carbonate
- C) Chitin
- D) Protein
- Answer: B) Calcium carbonate.
- Which of the following is a genus of sponges found in the class Calcarea?
- A) Chlamydomonas
- B) Clathrina
- C) Oscillatoria
- D) Amoeba
- Answer: B) Clathrina.
- Calcarea sponges are known for their ability to reproduce in which of the following ways?
- A) Only sexually
- B) Only asexually
- C) Both sexually and asexually
- D) Neither sexually nor asexually
- Answer: C) Both sexually and asexually.
- What is the primary role of choanocytes in Calcarea sponges?
- A) Structural support
- B) Food digestion
- C) Water circulation and filtering
- D) Reproduction
- Answer: C) Water circulation and filtering.
- Which feature distinguishes Calcarea sponges from other sponge classes?
- A) Presence of oscula
- B) Presence of calcium carbonate spicules
- C) Presence of siliceous spicules
- D) Presence of flagellated cells
- Answer: B) Presence of calcium carbonate spicules.
- What is the typical size range of Calcarea sponges?
- A) 1 mm to 10 cm
- B) 1 cm to 1 m
- C) 1 m to 5 m
- D) Over 5 m
- Answer: A) 1 mm to 10 cm.
- What is the ecological role of Calcarea sponges in marine environments?
- A) Predators
- B) Decomposers
- C) Primary producers
- D) Filter feeders
- Answer: D) Filter feeders.
- How do Calcarea sponges primarily obtain their food?
- A) Photosynthesis
- B) Filter feeding
- C) Predation
- D) Absorption through the skin
- Answer: B) Filter feeding.
- Which of the following structures is involved in water flow in Calcarea sponges?
- A) Osculum
- B) Spongocoel
- C) Pores
- D) All of the above
- Answer: D) All of the above.
- What type of symmetry do Calcarea sponges exhibit?
- A) Bilateral symmetry
- B) Radial symmetry
- C) Asymmetry
- D) None of the above
- Answer: B) Radial symmetry.
- What is the larval stage of Calcarea sponges called?
- A) Planula
- B) Trochophore
- C) Parenchymella
- D) Veliger
- Answer: C) Parenchymella.
- Which of the following is a characteristic feature of the class Calcarea?
- A) They are always brightly colored.
- B) They possess a spongin skeleton.
- C) They have small, tubular bodies.
- D) They can form large colonies.
- Answer: C) They have small, tubular bodies.
- What structure do Calcarea sponges use for excretion?
- A) Flagella
- B) Pores
- C) Osculum
- D) Choanocytes
- Answer: C) Osculum.
- Calcarea sponges typically have which of the following features?
- A) High reproductive rates
- B) Low metabolic rates
- C) Thick walls
- D) Complex canal systems
- Answer: B) Low metabolic rates.
- Which of the following is a function of the mesohyl in Calcarea sponges?
- A) Water circulation
- B) Nutrient transport
- C) Structural support
- D) All of the above
- Answer: D) All of the above.
- What is the habitat preference of Calcarea sponges?
- A) Deep sea environments
- B) Freshwater habitats
- C) Coastal marine waters
- D) Intertidal zones
- Answer: C) Coastal marine waters.
- Which of the following is true about Calcarea sponges?
- A) They are exclusively freshwater species.
- B) They can be both solitary and colonial.
- C) They lack any form of sexual reproduction.
- D) They are the largest sponges.
- Answer: B) They can be both solitary and colonial.
- In terms of biodiversity, Calcarea sponges are considered to be:
- A) Highly diverse
- B) Moderately diverse
- C) Low diversity
- D) Non-diverse
- Answer: C) Low diversity.
- What is a common predator of Calcarea sponges?
- A) Sea turtles
- B) Fish
- C) Sea stars
- D) Crabs
- Answer: C) Sea stars.
- How do Calcarea sponges respond to environmental changes?
- A) They remain unchanged.
- B) They can adapt quickly.
- C) They are sensitive and may decline in number.
- D) They migrate to new areas.
- Answer: C) They are sensitive and may decline in number.
- Which of the following reproductive strategies is common in Calcarea sponges?
- A) Budding
- B) Fission
- C) Fragmentation
- D) All of the above
- Answer: D) All of the above.
- What is the main threat to Calcarea sponges in their natural habitats?
- A) Climate change
- B) Overfishing
- C) Habitat destruction
- D) All of the above
- Answer: D) All of the above.
- Calcarea sponges are primarily found in which type of water?
- A) Saline
- B) Freshwater
- C) Brackish
- D) Ice-cold
- Answer: A) Saline.
- Which characteristic makes Calcarea sponges unique among other sponge classes?
- A) Presence of spongin
- B) Presence of a hard skeleton
- C) Presence of organic spicules
- D) Presence of siliceous spicules
- Answer: B) Presence of a hard skeleton.
- What is the typical coloration of Calcarea sponges?
- A) Bright red
- B) Muted colors
- C) Bioluminescent
- D) Green
- Answer: B) Muted colors.
- Which type of canal system is NOT found in Calcarea sponges?
- A) Asconoid
- B) Syconoid
- C) Leuconoid
- D) None of the above
- Answer: C) Leuconoid.
- What role do spicules play in Calcarea sponges?
- A) Protection and support
- B) Digestion
- C) Reproduction
- D) Locomotion
- Answer: A) Protection and support.