Science Final Term Exam Std. V 2023-2024

Skeleton and Joints

• The human skeleton consists of 206 bones, providing structure and support.
• Joints are the connections between two bones; they allow for movement and flexibility.
• The cranium protects the brain, forming the upper part of the skull.
• Major joint types include ball and socket (e.g., shoulder and hip) and hinge joints (e.g., elbow and knee).

Simple Machines

• A lever is a rigid bar that pivots around a point known as the fulcrum.
• First-class levers have the fulcrum located between the effort and load (e.g., the neck).
• Second-class levers have the load positioned between the fulcrum and the effort (e.g., a wheelbarrow).
• Simple machines, like levers and pulleys, reduce the amount of effort needed to perform work.

Types of Pulleys

• Fixed pulleys do not move and change the direction of the force applied.
• Movable pulleys provide a mechanical advantage by reducing the effort needed to lift a load.

Functions of the Skeletal System

• The skeletal system serves two primary functions: providing support to the body and protecting vital organs.
• It also facilitates movement in conjunction with muscles.

True or False Statements

• Important statements about human anatomy and simple machines include:
  • The knee joint is not a ball and socket joint; it is a hinge joint.
  • A wheelbarrow exemplifies a second-class lever.
  • Ribs are indeed part of the axial skeleton, which provides structure to the torso.

Examples and Applications

• A wedge, a type of simple machine, is used to split or cut objects.
• The action of the biceps lifting the forearm exemplifies a first-class lever in human physiology.
• Simple machines ease work efforts by allowing a smaller input force to generate a larger output force.