Ch.22 Echinodermata Flashcards
What is the primary characteristic of echinoderms?
a. Bilateral symmetry
b. Spiny exoskeleton
c. Soft body
d. Internal skeleton
b. Spiny exoskeleton
Why do echinoderms exhibit both radial and bilateral symmetry?
a. They are transitional organisms
b. They evolved from bilateral ancestors but adapted to a sessile lifestyle
c. They have evolved from radial ancestors to become free-moving
d. It allows them to have varied body plans for different environments
b. They evolved from bilateral ancestors but adapted to a sessile lifestyle
Which group of echinoderms lacks an endoskeleton?
a. Asteroidea
b. Echinoidea
c. Crinoidea
d. Holothuroidea
d. Holothuroidea
What is a characteristic feature of class Asteroidea?
a. Long jointed arms
b. Hard exoskeleton
c. Presence of madreporite
d. Water-vascular system with tube feet
d. Water-vascular system with tube feet
Why are crinoids considered to be more primitive in their characteristics than other echinoderms?
a. They lack a water-vascular system
b. They have a sessile lifestyle
c. They have bilateral symmetry
d. They lack madreporite openings
b. They have a sessile lifestyle
How do echinoderms primarily use their water-vascular system?
a. Locomotion and food gathering
b. Respiration and excretion
c. Defense against predators
d. Reproduction and larval development
a. Locomotion and food gathering
What is the main function of tube feet in echinoderms?
a. Gas exchange
b. Capturing prey
c. Movement and locomotion
d. Sensory perception
c. Movement and locomotion
How do sea stars benefit from their regenerative abilities?
a. They can escape from predators easily
b. They can reproduce asexually
c. They can recover from injuries and lost body parts
d. They can adapt to changing environmental conditions
c. They can recover from injuries and lost body parts
How are brittle star arms different from sea star arms?
a. Brittle star arms are shorter and thicker
b. Brittle star arms lack tube feet
c. Brittle star arms are distinct from the central disc
d. Brittle star arms have madreporite openings
c. Brittle star arms are distinct from the central disc
What is the primary difference between regular and irregular sea urchins?
a. Shape and symmetry
b. Size and coloration
c. Presence of spines
d. Feeding habits and habitat
a. Shape and symmetry
What is the function of Aristotle’s lantern in sea urchins?
a. Breathing
b. Feeding
c. Locomotion
d. Sensory perception
b.Feeding
What is a characteristic feature of class Holothuroidea?
a. Presence of a rigid endoskeleton
b. Use of tube feet for movement
c. External symmetry
d. Lack of water-vascular system
b. Use of tube feet for movement
What is the purpose of Cuvierian tubules in holothuroids?
a. Feeding
b. Locomotion
c. Defense against predators
d. Reproduction
c. Defense against predators
