Chapter 39

The vertebrate skin consists of an (a) outer epidermis and inner hypodermis (b) outer epidermis and inner endoskeleton (c) outer endodermis and inner epidermis (d) outer epidermis and inner dermis (e) outer subcutaneous layer and inner dermis.

Cells actively divide in (a) stratum basale (b) stratum corneum (c) stratum dermis (d) the layer with cells that contain keratin (e) two of the preceding answers are correct.

An endoskeleton (a) is typically composed of dead tissue (b) is characterized by fluid in a closed compartment (c) is typical of echinoderms (d) is typical of arthropods (e) requires the animal to molt.

Which of the following is not part of the axial skeleton? (a) skull (b) vertebral column (c) pelvic girdle (d) rib cage (e) sternum.

The thin outer shell of a long bone is made of (a) compact bone (b) spongy bone (c) epiphyses (d) cartilage (e) mainly chondrocytes.

Which of the following connects bones to one another? (a) tendons (b) ligaments (c) osteoclasts (d) synovial membranes (e) smooth fibers.

In endochondral bone development, (a) osteoclasts produce bone (b) joints connect fibers (c) the skeleton consists of cartilage (d) bones develop from cartilage templates (e) bones form in noncartilage connective tissue.

An energy storage compound that can be stockpiled in muscle cells for short- term use is (a) creatine phosphate (b) ADP (c) troponin (d) myosin (e) myoglobin.

Myosin binds to actin, forming a cross bridge. What happens next? (a) acetylcholine is released (b) calcium ions stimulate exposure of active sites (c) filaments slide past one another, and the muscle fiber shortens (d) myosin is activated (e) \(P_{i}\) is released, and the cross bridge flexes.

Calcium ions are released from the sarcoplasmic reticulum. What happens next? (a) acetylcholine is released (b) active sites on the actin filaments are exposed (c) filaments slide past one another, and the muscle fiber shortens (d) myosin is activated (e) \(P_{i}\) is released, and the cross bridge flexes.

When skeletal muscle is stimulated by a series of closely timed separate stimuli, (a) it responds with a smooth, sustained contraction called tetanus (b) a simple twitch occurs (c) white fibers respond (d) red fibers respond (e) muscle tone occurs.

Glycogen is (a) produced by actin (b) depleted within l second of strenuous activity (c) a form of long-term energy storage (d) synthesized when cross bridges form (e) depleted before creatine phosphate reserves are used.

Insect flight muscles (a) work best at low temperature (b) have a very high metabolic rate (c) do not create much lift (d) evolved after bird wings (e) are always attached directly to the wing and make up the bulk of the wing.

Which of the following pairs of systems function together most closely? (a) integumentary and skeletal (b) integumentary and cardiovascular (c) muscular and epithelial (d) skeletal and muscular (e) epithelial and muscular.