Concept explainers
Introduction: Endoskeleton is the internal tough framework of the animal’s body. Endoskeleton provides rigidity and shape to the body and it cannot be seen from outside, because endoskeleton is covered by various kinds of tissues and organs.
Answer to Problem 1TYU
Correct answer: An endoskeleton is found observed in echinoderms and vertebrates. Hence, the correct answer is the option (c).
Explanation of Solution
Reason for correct answer:
Echinoderms and vertebrates have their skeleton inside their body thus the skeleton is known as endoskeleton. In echinoderms, epidermis covers their internal skeleton, which is made up of calcareous plates and spines and is embedded in the body wall. Vertebrate’s endoskeleton is made up of bones, which gives strength and protection to the vertebrates and also transmit muscle forces.
Option (c) is given as “is found mainly in echinoderms and vertebrates”.
In echinoderms and vertebrates, an endoskeleton is found. Hence, the correct answer is the option (c).
Reasons for incorrect answers:
Option (a) is given as, “is typically composed of dead tissue”.
Endoskeleton is made up of living tissues, which get bigger along with the animal growth. Hence, option (a) is incorrect.
Option (b) is given as, “is characterized by fluid in a closed compartment”.
Endoskeleton is not characterized by fluid in a closed compartment because it consists of calcareous bones and cartilage. Hence, option (b) is incorrect.
Option (d) is given as, “is typical of echinoderms and arthropods”.
Yes, in echinoderms, endoskeleton is a characteristic feature, but in arthropods, in spite of endoskeleton, the exoskeleton, of cuticle layer, is present which is made up of nonliving material, chitin. Hence, option (d) is incorrect.
Option (e) is given as, “requires the animal to molt”.
Molting is required in the animals, which have an exoskeleton, and to accommodate growth, animals shed off their exoskeleton and replace it with the new exoskeleton. Hence, option (e) is incorrect.
Hence, the options (a), (b), (d), and (e) are incorrect.
Endoskeleton is the internal framework of body and primarily found in echinoderms and vertebrates.
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Chapter 40 Solutions
BIOLOGY W/MINDLINK AND MINDTAP
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