Evolution of Tetrapod Vertebrae
41 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What adaptation do reptiles have to better resist desiccation?

  • Moist skin surface
  • Thin stratum corneum
  • Dense blood vessel network
  • Highly keratinized cells (correct)
  • What is a characteristic feature of the epidermis in reptiles?

  • Horny scales (correct)
  • Feathers
  • Mucus glands
  • Hair follicles
  • What purpose do the granular glands in toads serve?

  • Aid in breeding
  • Assist in locomotion
  • Secrete moisture
  • Defensive secretion (correct)
  • In snakes, what modification do scales on the ventral surface undergo?

    <p>They turn into scutes</p> Signup and view all the answers

    How can the age of turtles be determined?

    <p>Counting ring formations</p> Signup and view all the answers

    What modification is seen in the tails of rattlesnakes?

    <p>Epidermis modification</p> Signup and view all the answers

    Which is NOT a characteristic found in the stratum corneum of reptiles?

    <p>Feathers</p> Signup and view all the answers

    What type of environment does the epidermis of reptiles ultimately adapt to?

    <p>Desert</p> Signup and view all the answers

    What characterizes the notochord in its early development?

    <p>It is mineralized and unsegmented.</p> Signup and view all the answers

    What is one of the primary functions of the vertebral column?

    <p>To provide support and flexibility to the trunk.</p> Signup and view all the answers

    How does the vertebral column provide flexibility?

    <p>Through the intervertebral discs.</p> Signup and view all the answers

    What primarily comprises the notochord?

    <p>Dense fibrous connective tissue.</p> Signup and view all the answers

    Which of the following is NOT a characteristic of the vertebral column?

    <p>Provides a fixed support structure.</p> Signup and view all the answers

    What characterizes the structure of horns?

    <p>They have a bony core covered by skin.</p> Signup and view all the answers

    Which statement accurately describes antlers?

    <p>They have a protective covering called velvet.</p> Signup and view all the answers

    What type of glands aid in heat regulation and are associated with hair?

    <p>Sebaceous glands</p> Signup and view all the answers

    What is a key feature of rhinoceros horns?

    <p>They consist of hairlike keratin fibers woven together.</p> Signup and view all the answers

    Which type of gland secretes cerumen in the outer ear?

    <p>Ceruminous glands</p> Signup and view all the answers

    Which of the following statements about epidermal glands is correct?

    <p>They help protect the skin and its structures.</p> Signup and view all the answers

    What describes the classification of glands based on their structure?

    <p>Simple and compound</p> Signup and view all the answers

    Which type of gland is absent in pangolins and echidnas?

    <p>Sweat glands</p> Signup and view all the answers

    What structure is formed by the left and right laminae of bone in relation to the spinal cord?

    <p>Neural arch</p> Signup and view all the answers

    In which group does the persistence of the notochord occur with no centra developed?

    <p>Chondrostei</p> Signup and view all the answers

    Which cartilage is associated with the notochord and is described as being 'in between'?

    <p>Interdorsal</p> Signup and view all the answers

    What is the significance of the hypocentrum in early vertebrate evolution?

    <p>It cradled the notochord as a U-shaped anterior bone.</p> Signup and view all the answers

    Which group of vertebrates is characterized by having an enlarged pleurocentrum?

    <p>Amniotes</p> Signup and view all the answers

    What feature characterizes the intercentrum in various vertebrate groups?

    <p>It varies in size compared to pleurocentra.</p> Signup and view all the answers

    What distinguishes the Stereospondyli group of vertebrates from their ancestors?

    <p>They exclusively retained intercentrum.</p> Signup and view all the answers

    What cartilage is positioned dorsally and is characterized as 'basic dorsal'?

    <p>Basidorsal</p> Signup and view all the answers

    Which evolutionary lineage is noted for having bones in several segments?

    <p>Rhipidistian</p> Signup and view all the answers

    What is true regarding the cartilages associated with the notochord?

    <p>They provide structural support alongside the notochord.</p> Signup and view all the answers

    What is the primary reason living reptiles such as birds and opossums have more cervical vertebrae than mammals?

    <p>The increased number allows more room for movement.</p> Signup and view all the answers

    Which characteristic is unique to the synsacrum in birds?

    <p>The fusion of various types of vertebrae with the pelvic girdle.</p> Signup and view all the answers

    What distinguishes the vertebrae of mammals from those of reptiles when it comes to mobility?

    <p>Mammals have a flatter surface on their centra.</p> Signup and view all the answers

    How many cervical vertebrae do most mammals have?

    <p>7</p> Signup and view all the answers

    Why might a giraffe have a relatively small number of cervical vertebrae compared to its neck length?

    <p>It has longer vertebrae that compensate for the fewer number.</p> Signup and view all the answers

    What is the significance of stout transverse processes in the sacral vertebrae of bears?

    <p>They support the pelvic girdles during movement.</p> Signup and view all the answers

    Which of the following describes the sacral vertebrae of amphibians?

    <p>They only have one transverse process.</p> Signup and view all the answers

    How many fused sacrals and caudals do armadillos have in their synsacrum?

    <p>Up to 13</p> Signup and view all the answers

    What feature limits the flexibility of the avian backbone caudal to the neck?

    <p>The rigidity of the synsacrum.</p> Signup and view all the answers

    Which of the following mammals is an exception to the typical number of cervical vertebrae?

    <p>Manatee, which has 6.</p> Signup and view all the answers

    Study Notes

    Sarcopterygians

    • Dipnoans, chondrostei, and coelacanth develop no centra.
    • Notochord is present and unconstricted.
    • Notochord sheath contains little cartilage or bone.
    • Basidorsal, basiventral, interdorsal, and intervertebral cartilages associated with the notochord.

    Evolution of Tetrapod Vertebrae

    • Rhipidistians and early labyrinthodonts consisted of several bones per segment.
    • Hypocentrum is a median, U-shaped anterior bone that cradled the notochord.
    • Pleurocentra are small wedges of bone overlying the notochord dorsolaterally.
    • Laminate of bone, lateral to the spinal cord, collectively form a neural arch.

    Rhachitomi

    • Large intercentrum and a small pleurocentrum.
    • Considered to be the ancestor.

    Stereospondyli

    • Retained only the intercentrum.
    • Older descendants

    Embolomeri

    • Increased size of pleurocentrum to the size of the intercentrum.
    • Dual centra are seen.

    Amniotes

    • Enlarged pleurocentrum to near or complete exclusion of the intercentrum.
    • Intercentrum is eliminated.

    Integumental Adaptations

    • Show advanced integumental adaptations to the terrestrial environment.
    • Cells are more highly keratinized.
    • Integument is modified into horny scales in snakes and lizards.

    Epidermis of Reptiles

    • Ultimate adaptation of craniate skin for surviving in an arid environment.
    • Horny scales, scutes, beaks, rattles, claws, plaques and spiny crests are found in the stratum corneum.

    Granular Glands

    • Present in toads.
    • Secrete irritating alkaloids substances which are defensive in nature.

    Keratin

    • Aquatic urodeles have thin desiccation-impending stratum of cornified cells.

    Horns

    • Permanent.
    • Have bone inside then covered by the skin.
    • Not shed.
    • Surrounding the bony core is a highly keratinized layer of epidermis.

    Antlers

    • Not present throughout the year.
    • Shed during non-breeding season.
    • Develop a protective covering of skin - velvet.

    Mucous Glands

    • Lost significance due to the cornification of skin.
    • Absent in tetrapods except in mammals.

    Sebaceous Glands

    • Associated with hair.
    • Present when there are hairs and sebum is exuded into hair follicles.
    • Aid in heat regulation.
    • Ceruminous glands secrete cerumen (wax) in the outer ear.
    • Ceruminous glands give off scents.
    • Meibomian glands assist in lubrication of the conjunctiva of the eye.

    Sudoriferous or Sweat Glands

    • Present in furry animals in areas like the feet, lips, and the sides of the head.
    • Absent in pangolins, sirenians, cetaceans, and echidnas.

    Vertebral Column

    • Segmented, more or less flexible, arched rod flanked by axial musculature.
    • Function: Suspends the trunk, holds the trunk in either upright or transverse position.
    • The mineralization of the notochord.

    Cervical Vertebrae

    • Increased number of cervical vertebrae allows for more movement.
    • Commonly 12.
    • Can reach 25 in swans.

    Transverse Processes

    • Living reptiles, most birds, and opossums have 2 transverse processes.
    • Most mammals have 3 to 5 (ankylosed).
    • Perissodactyls can have up to 8.
    • Edentates can have up to 13.

    Synsacrum

    • Special type of vertebra.
    • Fusion of the last thoracic, all lumbars, sacrals and the first few caudals with the pelvic girdle.
    • Provides rigid brace for the stance of birds.
    • Little flexibility in the avian backbone caudal to the neck.

    Sacral Vertebrae

    • Bears hold stout transverse processes to bear the thrust of the pelvic girdles.

    Caudal Vertebrae

    • Early tetrapods usually had 50 or more.
    • Amphibians have only 1 transverse process in the sacral vertebra.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Description

    Explore the complex evolution of tetrapod vertebrae, including the characteristics of early groups like sarcopterygians, Rhachitomi, and Stereospondyli. This quiz covers key anatomical features, bone structures, and the progression towards modern vertebrate forms. Test your understanding of these critical evolutionary developments.

    More Like This

    Evolution of Amphibians and Tetrapods Quiz
    5 questions
    Amniotes Evolution Quiz
    5 questions

    Amniotes Evolution Quiz

    TrustworthyBurgundy7411 avatar
    TrustworthyBurgundy7411
    Evolution of Fish to Tetrapods Quiz
    40 questions
    Use Quizgecko on...
    Browser
    Browser