A.

Muscular dystrophy

Progressive degeneration of skeletal muscle mostly due to genetic disorder is muscular dystrophy.

Tetany is muscular spasm due to low calcium in body fluid.

Myasthenia gravis is an anto immume disorder leading to paralysis of skeletal muscles.

Botulism is rare and dangerous type of food poisoning caused by bacterium Clostridium Botulinum. 

C.

There are seven pairs of vertebrosternal, three pairs of vertebrochondral and two pairs of vertebral ribs.

Among the given options, option 3 is the correct option.

Vertebrosternal ribs are true ribs, dorsally they are attached to the thoracic vertebrae and ventrally connected to the sternum with the help of hyaline cartilage. First seven pairs of ribs are called true ribs.

8th, 9th and 10th pairs of ribs do not articulate directly with the sternum but join the seventh ribs with the help of hyaline cartilage. These are vertebrochondral or false ribs.

Last 2 pairs (11 & 12) of ribs are not connected ventrally and are therefore, called floating ribs.

Only first seven pairs of ribs are ventrally connected to the sternum.

A.

dense regular connective tissue-

Fibres and fibroblasts are compactly packed in the dense connective tissues. Orientation of fibres show a regular or irregular pattern and are called dense regular and dense irregular tissues. In the dense regular connective tissues, the collagen fibres are present in rows between many parallel bundles of fibres. Tendons, which attach skeletal muscles to bones and ligaments which attach one bone to another are exam pies of this tissue.