8th Grade Science Part 1-1 - The Human Body

Explanation
The correct answer is 206. This is because an adult human body typically has 206 bones. These bones make up the skeletal system, providing support, protection, and allowing for movement.

Explanation
Skeleton functions include shape and support, as it provides the framework for the body and helps maintain its shape. The skeleton also plays a crucial role in protection, as it surrounds vital organs such as the brain, heart, and lungs, shielding them from potential injuries.

Explanation
Cartilage is the correct answer because it is a smooth, shiny, and flexible connective tissue that covers the ends of bones in joints. It provides support, cushioning, and reduces friction between bones during movement. Unlike bones, cartilage does not contain blood vessels, which contributes to its shiny appearance. Additionally, cartilage is not made of plastic, salt, or blood, making them incorrect options.

Explanation
Bones are indeed alive as they contain living cells and require a blood supply to provide them with oxygen and nutrients. The cells within bones are responsible for their growth, repair, and remodeling. Additionally, bones play a crucial role in supporting the body, protecting organs, and producing blood cells. Therefore, it is accurate to say that bones are alive.

Explanation
Ossification refers to the natural process of bone formation and hardening that occurs as a person ages. It involves the deposition of calcium and other minerals in the bone matrix, making the bones stronger and more rigid. This process is essential for maintaining the structural integrity and strength of the skeletal system. As individuals grow older, ossification helps prevent bone loss and maintain overall bone health.

Explanation
Osteoporosis is a disease of the bone that weakens the bone structure and makes them more prone to fractures. It is not a skin disease or something that is not important. Osteoporosis is a significant health concern as it can lead to severe complications and decreased quality of life for individuals affected by it.

Explanation
The given answer lists the three types of joints correctly. Hinge joints, such as the knee and elbow, allow movement in only one direction, like the opening and closing of a door. Pivot joints, like the joint between the skull and spine, enable rotation or twisting movements. Ball and socket joints, found in the hip and shoulder, allow for a wide range of motion in multiple directions, including rotation and circumduction. The answer does not include the "stick joint" because it is not a recognized type of joint in human anatomy.