Which type of bone, found in the wrist and ankle, is approximately as long as it is wide and is responsible for providing stability and support to the joints?

Correct Answer: B

Rationale: Short bones, like the carpals (wrist) and tarsals (ankle), are roughly equal in length and width, providing stability and support to joints while allowing some movement. Long bones are in limbs, irregular bones have complex shapes, and flat bones are protective, making 'Short bone' the correct answer.

Correct Answer: B

Rationale: When muscle fibers contract, sarcomeres (the units between Z-lines) shorten as actin and myosin filaments slide past each other, per the sliding filament theory. This reduces sarcomere length, contracting the muscle, making 'Sarcomeres shorten' the correct answer.

Correct Answer: A

Rationale: Bones require protection and nutrition to stay healthy. Wearing a helmet (Choice A) prevents skull fractures during activities like biking. Other correct options from the document include wearing pads, using sports equipment, avoiding trampolines, eating calcium-rich foods, and being active. Sitting all day, eating candy, and skipping exercise weaken bones, making 'wear a helmet' a representative correct choice.

Correct Answer: D

Rationale: Bones are classified by shape: long (e.g., femur), short (e.g., carpals), flat (e.g., scapula), irregular (e.g., vertebrae), and sometimes sesamoid (round, e.g., patella). 'Square,' 'cubed,' and 'triangular' are not standard categories; 'round' aligns with sesamoid bones, making 'long, short, flat, irregular and round' the most accurate.

Correct Answer: C

Rationale: The diaphysis, or shaft, of a long bone is primarily compact bone, providing strength and support. Spongy bone is in the epiphyses, hyaline cartilage covers joint surfaces, and fibrous tissue forms membranes like the periosteum, making 'compact bone' the correct answer.