BSC 215 Lecture Notes - Lecture 16: Appendicular Skeleton, Axial Skeleton

1. Consider the following eight statements about vertebrae. Which four of the following eight statements are TRUE? Choose all four correct answers.

(a) In Actinopterygii, Chondrichthyes, and some Amphibia (and one unusual taxon of Lepidosauria), the vertebrae have centra which surround the notochord.

(b) Some vertebrae have processes such as spines that function as sites for muscle attachment.

(c) in many vertebrate taxa, the vertebrae are composed of dermal bone.

(d) In tetrapods, the vertebrae have processes called zygapophyses that function as specialized sites for articulation with the ribs.

(e) Vertebrae arise from sclerotome epimere mesoderm.

(f) All extant vertebrate taxa have vertebrae.

(g) Some vertebrae have hemal arches which protect blood vessels (such as the dorsal aorta).

(h) Vertebrae have neural arches which protect the notochord.

2. While walking through the halls of the Biosciences building, you find a single vertebra lying on the floor. You notice that it does not have zygapophyses. It has an amphicoelous centrum, and it has both a neural arch and a hemal arch. This vertebra is completely ossified. Identify to which vertebrate taxon this vertebra belongs, and to which region of the vertebral column.

(a) caudal region - Petromyzontida

(b) thoracic region - Aves

(c) trunk region - Chondrichthyes

(d) trunk region - Actinopterygii

(e) caudal region - Actinopterygii

(f) caudal region - Amphibia

(g) caudal region - Chondrichthyes

3. You are doing a study on the diet of polar bears. While examining the scat (droppings) of a large polar bear, you find a single vertebrae. You need to identify this vertebra to determine what this polar bear has been eating. Polar bears are known to eat mammals, birds, and some fish (Actinopterygii). This vertebra has a heterocoelous centra and it has no articulation sites for ribs. It also has an odontoid process. To which of these three vertebrate taxa, and to which region of the vertebral column does this vertebra belong?

(a) synsacral region - Aves

(b) cervical region - Mammalia

(c) trunk region - Actinopterygii

(d) cervical region - Aves

(e) caudal region - Actinopterygii

(f) thoracic region - Mammalia

4. Which four of the following eight statements about the skeleton are TRUE? (Choose all four correct options.)

(a) Bone is a tissue that is able to withstand large tensile forces but not large compressive forces.

(b) An important role of the vertebral column in actinopterygii and chondrichthyes is to support the body weight.

(c) in amniotes, the ribs consist of two parts, a costal rib (which articulates with a thoracic vertebra) and a sternal rib (which articulates with the sternum). The mobile joints between the costal and sternal rib, as well as between the costal rib and the vertebra and between the sternal rib and the sternum, make the ribcage flexible such that it can expand during breathing.

(d) A vertebral column with procoelous centra would have a greater range of mobility than a vertebral column with acoelous centra.

(e) In all extant vertebrate taxa, the vertebral column provides axial structural support, as well as support for locomotion.

(f) In many mammals, ligaments and muscles attaching to the neural spines of vertebrae help to stabilize the vertebral column and pull it into a stable arch, which helps to efficiently bridge the body weight to the legs.

(g) In tetrapods, the pectoral girdle is firmly fused to the vertebral column to allow for efficient transfer of locomotive forces from the forelimbs to the axial skeleton.

(h) In chondrichthyes, actinopterygii, sarcopterygii, and some tetrapods, the vertebral column acts as a firm but flexible rod on which muscles pull to produce lateral undulations of the body for locomotion.

5. Consider the following eight statements about the form and function of the appendicular skeleton. Which four of the following eight statements are TRUE? (Choose all four correct options.)

(a) In sharks (Chondrichthyes), the pectoral and pelvic fins are mainly used for propulsion - to propel the body forward through the water.

(b) The tips of fins are supported by fin rays, thin rods which support a webbing of skin (and sometimes also connective tissue) - this increases the surface area of the fin

(c) The fleshy fins of sarcopterygii are not very maneuverable, and are used only to stabilize the body by preventing roll, pitch, and yaw when swimming rapidly.

(d) In both actinopterygii and chondrichthyes, the pectoral girdle attaches directly to the back of the skull while the pelvic girdle is embedded in the muscle of the body wall.

(e) In both sharks (Chondrichthyes) and actinopterygii, the pectoral and pelvic fins provide stability while swimming by preventing roll, pitch, and yaw.

(f) In male chondrichthyes, the pelvic fins have special extensions called claspers that are used to transfer sperm to females during copulation for internal fertilization.

(g) Petromyzontida and myxinoidea have paired pectoral and pelvic fins that are used to provide stability while swimming, as well as for steering.

(h) The main functions of girdles are to provide attachment sites for the muscles of the appendages (paired fins or limbs) and to stabilize the appendages.

6. Consider the following statements related to the appendicular skeleton and terrestrial locomotion of tetrapods. Which three of the following six statements are CORRECT? (Choose all three correct options.)

(a) In tetrapods with erect limb posture, the limbs are positioned directly under the body, while in tetrapods with sprawled limb posture, the limbs are positioned to the sides of the body.

(b) In terrestrial tetrapods, the distal ends of the humerus and femur are rotated such that the digits are oriented in line with the direction of travel, increasing both tractive and propulsive forces during terrestrial locomotion.

(c) Tetrapods with digitigrade foot posture have relatively longer limbs than tetrapods with plantigrade foot posture, such that they have a greater stride length.

(d) When terrestrial tetrapods are walking or running, the recovery stroke of the limbs involves the limb touching the ground while the propulsive stroke of the limbs involves the limb being lifted and moving from posterior to anterior.

(e) In tetrapods with sprawled limb posture, the dorsal elements of the pectoral girdle (such as the scapula) are much larger than the ventral elements of the pectoral girdle (such as the clavicle and corocoid).

(f) When walking or running, tetrapods with erect limb posture use an overarm swing for the recovery stroke, which is relatively slow.

7. You are walking along the beach and find a skeleton in the sand. You notice that the pelvic girdle is not fused to the vertebral column while the pectoral girdle is fused to the skull. The distal ends of the appendages have fin rays. It appears that all muscles controlling the appendages were located within the body wall, not within the appendages. To which vertebrate taxon does this skeleton belong?

(a) Sarcopterygii

(b) Lepidosauria

(c) Elasmobranchii

(d) Amphibia

(e) Actinopterygii

(f) Petromyzontida

8. Your neighbour finds a skeleton while cleaning out the pond in her backyard, and she asks you to identify it. You notice that the vertebrae have zygapophyses and that the centra of the vertebrae are procoelous. The ribs are quite short, and articulate with the vertebrae but not with the sternum. The pelvic and pectoral girdles appear robust and highly ossified, and the pectoral girdle has enlarged ventral elements but relatively small dorsal elements. The appendages each have five digits. Identify this skeleton for your neighbour, and describe to her as much as you can about its style of locomotion, based on this information about its axial and appendicular skeleton. (Choose all three correct options.)

(a) This skeleton is most likely from an amphibian.

(b) This skeleton is most likely from a sarcopterygian.

(c) This skeleton is most likely from a lizard (Lepidosauria).

(d) This animal most likely had sprawled limb posture.

(e) This animal most likely could not support its own body weight using its appendages, and so would not have been capable of terrestrial locomotion.

(f) This animal probably walked with lateral undulations of the body, using the feet as pivot points.

(g) This animal most likely walked with a recovery stroke that used an energetically efficient pendulum-like swing.

(h) This skeleton is most likely from a crocodilian (Archosauria).

Mutants and mutant genes, 5 points You are studying a gene in chickens named “boneless”, named after its mutant phenotype. The wild type boneless gene encodes a protein that is 400 amino acids long. When a chicken lacks a wild type copy of the gene (in other words, when both of its copies are the boneless mutant version), it grows as a jiggly blob with eyes floating on top.

(A) The wild type function of the boneless gene is most likely to make ________________.

(B)To detect where boneless is expressed during embryogenesis you decide to perform an in situ hybridization experiment with a fluorescently labeled probe. To make this probe, what would you use as the template? Circle your answer and explain in one sentence why your answer is the better of the two choices.

(1) genomic DNA of boneless, which includes 4 exons and 3 introns (2) cDNA of boneless

(C) Given the phenotype of boneless, what can you conclude about the kind of gene that boneless encodes: (circle the correct answer)

(1) it must be a transcription factor (e.g. like pax6) (2) it must be a receptor (e.g. like the insulin receptor) (3) it must encode a calcium channel protein for strong bones (4) it must encode a microRNA gene (5) it must encode a housekeeping gene (6) nothing can be concluded about what kind of product this gene encodes based its mutant phenotype

(D) Although flies do not have bones, you discover that flies have a homolog of boneless called “puddle”. What must be true about puddle?

(1) flies don’t need bones, therefore they have a puddle gene (2) flies lack bones because they lack boneless (3) the puddle gene makes flies boneless (4) puddle and boneless are sequences that arose from a common ancestral gene

1

The Romans created which of the following innovations in architecture that allowed them to build structures higher and stronger than any civilization before them?

2

A dome is an arch rotated 360 degrees.

True
False

3

Vaulted arches are:

4

Frank Gehry's design for Disney Hall in downtown Los Angeles employs the visual language of architecture. This means that the undulating curvilinear lines of the shapes which comprise the outside of the concert hall can convey the function of the hall.

Disney Hall is a performing art space for music and Gehry's curvilinear shapes could be interpreted as creating a feeling of music-like rhythm.

True
False

5

Which of the following relates to "green architecture"?

6

An example of "green architecture" is the Busnell House in California.

Which of the following is a reason why this house is considered "green architecture"?

7

Skeleton-and-skin architecture was used on the Seagram Building in NYC.

This building also represents the International Style; a style of architecture that emphasized an elaborate system of embelished organic designs and curvilinear forms.

True
False

8

The Geodesic Domes designed by Buckminster Fuller are based on the way honeybees construct honeycombs.

True
False

9

An example of the visual language of architecture is Santiago Calatrava's Path station at Ground Zero, which is designed like the skeleton of a bird. The Path station will be a new hub for the downtown area of Wall Street, where Ground Zero is located. Thus, the bird shape can convey both flight and hope for the memorial site at Ground Zero.

True
False

10

New technologies like CATIA computer software designed for the aerospace industry has allowed architects like Santiago Calatrava and Frank Gehry to make shapes that have curvilinear lines and twist and turn in space.

True
False