Question

Assertion: The first seven pairs of ribs are called true ribs.
Reason: These ribs are connected ventrally to the sternum
A. If both assertion and reason are true and the reason is the correct explanation for assertion
B. If both assertion and reason are true but the reason is not the correct explanation for assertion
C. If the assertion is true but the reason is false
D. If both assertion and reason are false

Answer 1

A set of twelve paired bones are known as the ribs. These bones form a cage-like structure to form the rib cage, which has a protective function on the thorax, where many vital organs are situated. The ribs are classified into three types namely true ribs, false ribs, and floating ribs.

Complete answer: The first seven pairs or sets of ribs are known as true ribs. They are called so because it has an attachment to both dorsal and ventral sides. Dorsally it is connected to the vertebrae and ventrally they are connected to the breast bone or the sternum. Thus both the statement, assertion and reason are true and the reason is the correct explanation for the assertion.
Hence, the correct answer is Option A.

Note: The two other types of ribs are known as false and floating ribs. The next five pairs of ribs after the seventh pair are known as the false ribs since they are not directly connected to the sternum, unlike the true ribs. The final two pairs are known as floating ribs, as they have connections only with the vertebrae and not ventrally to the sternum.