- What is the primary characteristic of sponges in the class Demospongiae?
- A) They have calcareous spicules.
- B) They have siliceous spicules and a fibrous skeleton.
- C) They lack spicules.
- D) They have organic spicules.
- Answer: B) They have siliceous spicules and a fibrous skeleton.
- Demospongiae sponges are commonly known for their:
- A) Glass-like structure
- B) Spongy texture
- C) Calcium carbonate composition
- D) Bright colors
- Answer: B) Spongy texture.
- Which type of body plan is predominantly found in Demospongiae sponges?
- A) Asconoid
- B) Syconoid
- C) Leuconoid
- D) Both A and B
- Answer: C) Leuconoid.
- What type of spicules do Demospongiae sponges possess?
- A) Siliceous spicules only
- B) Calcitic spicules
- C) Siliceous spicules, often reinforced with spongin
- D) Organic spicules only
- Answer: C) Siliceous spicules, often reinforced with spongin.
- Where are Demospongiae sponges primarily found?
- A) Freshwater habitats
- B) Terrestrial environments
- C) Marine and freshwater environments
- D) Intertidal zones only
- Answer: C) Marine and freshwater environments.
- Which of the following is a common characteristic of Demospongiae sponges?
- A) They are exclusively marine.
- B) They can have both hard and soft bodies.
- C) They lack a true cellular organization.
- D) They do not filter feed.
- Answer: B) They can have both hard and soft bodies.
- Demospongiae sponges typically reproduce through which method?
- A) Asexual reproduction only
- B) Sexual reproduction only
- C) Both asexual and sexual reproduction
- D) Budding only
- Answer: C) Both asexual and sexual reproduction.
- What is the ecological role of Demospongiae sponges in aquatic environments?
- A) Primary producers
- B) Filter feeders
- C) Predators
- D) Decomposers
- Answer: B) Filter feeders.
- Demospongiae sponges are characterized by their:
- A) High metabolic rates
- B) Unique canal systems
- C) Simple body structure
- D) Ability to photosynthesize
- Answer: B) Unique canal systems.
- What type of feeding mechanism do Demospongiae sponges utilize?
- A) Absorption
- B) Filter feeding
- C) Photosynthesis
- D) Predation
- Answer: B) Filter feeding.
- Which of the following best describes the physical structure of Demospongiae sponges?
- A) Gelatinous and soft
- B) Rigid and hard
- C) Flexible and leathery
- D) Hard and calcareous
- Answer: C) Flexible and leathery.
- Demospongiae sponges can be found at what depths in the ocean?
- A) Less than 10 meters
- B) 10 to 100 meters
- C) 100 to 1000 meters
- D) They can be found at all depths, including deep-sea habitats.
- Answer: D) They can be found at all depths, including deep-sea habitats.
- Which of the following is NOT a characteristic of Demospongiae sponges?
- A) Siliceous spicules
- B) Presence of oscula
- C) Complex canal systems
- D) Ability to photosynthesize
- Answer: D) Ability to photosynthesize.
- What larval stage do Demospongiae sponges undergo?
- A) Planula
- B) Parenchymella
- C) Trochophore
- D) Veliger
- Answer: A) Planula.
- Which of the following is a genus of sponges in the class Demospongiae?
- A) Clathrina
- B) Spongilla
- C) Euplectella
- D) Oscillatoria
- Answer: B) Spongilla.
- What is the primary mode of locomotion for Demospongiae sponges?
- A) Swimming
- B) Crawling
- C) They are sessile (non-moving).
- D) Burrowing
- Answer: C) They are sessile (non-moving).
- Which type of skeleton do Demospongiae sponges have?
- A) Calcareous skeleton
- B) Siliceous skeleton
- C) Organic skeleton
- D) No skeleton
- Answer: B) Siliceous skeleton.
- Demospongiae sponges are known for their:
- A) Rapid growth
- B) Long lifespan
- C) Bright coloration
- D) Ability to regenerate quickly
- Answer: B) Long lifespan.
- What is the role of the mesohyl in Demospongiae sponges?
- A) Water circulation
- B) Nutrient transport and structural support
- C) Gas exchange
- D) All of the above
- Answer: B) Nutrient transport and structural support.
- Which ecological role do Demospongiae sponges fulfill?
- A) Primary consumers
- B) Secondary producers
- C) Decomposers
- D) Filter feeders and habitat providers
- Answer: D) Filter feeders and habitat providers.
- What is a common method of asexual reproduction in Demospongiae sponges?
- A) Budding
- B) Fission
- C) Fragmentation
- D) All of the above
- Answer: D) All of the above.
- Which of the following is a significant aspect of the biology of Demospongiae sponges?
- A) They are strictly freshwater species.
- B) They possess true tissues.
- C) They can survive in extreme temperatures.
- D) They have a unique reproductive cycle.
- Answer: D) They have a unique reproductive cycle.
- What is the primary threat to Demospongiae sponges in their natural habitat?
- A) Pollution
- B) Overfishing
- C) Habitat destruction
- D) All of the above
- Answer: D) All of the above.
- Demospongiae sponges can be found in which marine environments?
- A) Coral reefs
- B) Deep-sea habitats
- C) Intertidal zones
- D) All of the above
- Answer: D) All of the above.
- What structure is responsible for water entry in Demospongiae sponges?
- A) Osculum
- B) Ostia
- C) Spongocoel
- D) Choanocytes
- Answer: B) Ostia.
- Which of the following feeding mechanisms is NOT utilized by Demospongiae sponges?
- A) Filter feeding
- B) Active predation
- C) Absorption
- D) Both A and C
- Answer: B) Active predation.
- What is the main component of the skeleton in many Demospongiae sponges?
- A) Calcium carbonate
- B) Silica
- C) Keratin
- D) Chitin
- Answer: B) Silica.
- Demospongiae sponges are characterized by their:
- A) High diversity
- B) Low diversity
- C) Ability to thrive only in shallow waters
- D) Absence of pores
- Answer: A) High diversity.
- Which of the following features helps Demospongiae sponges adapt to different environments?
- A) Ability to photosynthesize
- B) Versatile body forms
- C) Rapid reproductive rates
- D) Both B and C
- Answer: D) Both B and C.
- What is the primary function of choanocytes in Demospongiae sponges?
- A) To provide structural support
- B) To aid in reproduction
- C) To facilitate water flow and filter feeding
- D) To assist in locomotion
- Answer: C) To facilitate water flow and filter feeding.