Chapter 32, Problem 18A

Summary Introduction

Introduction:

Bone and cartilages are types of connective tissue. The skeleton system of the human body is made up of bones of different shapes and sizes. Long bones are present in arms and legs. Wrist bones are short bones. Skull is made up of flat bones. Vertebrae and facial bones are irregular bones.

Answer to Problem 18A

Correct answer:

The correct answer is option (a) production of vitamin D.

Explanation of Solution

Explanation/justification for the correct answer:

Option (a) production of vitamin D. vitamin D in the human body is produced by the skin. When the skin gets an ultraviolet ray from the sun, the cholesterol present in the skin is converted into vitamin D. So, the production of vitamin D cannot be a function of bone.

Explanation for incorrect answer:

Option (b) internal support. Bones in the human body forms the whole skeleton system which provides support to the whole body of a human. Long bone in the human body provides supports and bears all the weight of the body.

Option (c) protection of internal organs. Bones in the human body protect internal organs. Ribs in the body protect the lungs and heart in the human body. Skull protects the brain in the human body.

Option (d) storage of calcium. Bones are made up of calcium. Bone contains 50 percent minerals out of which 64 percent is calcium. Calcium hardens the framework and provides support to the bones.

Conclusion

Skin produces vitamin D in presence of ultraviolet rays from the sun. Hence the production of vitamin D cannot be a function of bone. So, option (a) is a correct answer.