1. What is the purpose of the periosteum, the tough outer layer of bone?

A. Produces red blood cells
B. Provides protection and nourishment to bone
C. Forms the joint surface
D. Stores minerals

Correct answer: B

Rationale: The correct answer is B: 'Provides protection and nourishment to bone.' The periosteum is a tough outer layer of bone that serves multiple functions. It provides protection by acting as a barrier against infections and injuries. Additionally, the periosteum contains blood vessels that supply nutrients to the bone cells, aiding in bone growth, repair, and maintenance. While red blood cells are produced in the bone marrow, not in the periosteum, the periosteum's primary role is to support the overall health and integrity of the bone structure.

2. Two identical balls, one made of clay and the other made of steel, are dropped from the same height. Which ball reaches the ground first, neglecting air resistance?

A. The clay ball due to its lower density
B. The steel ball due to its higher density
C. Both balls reach the ground simultaneously
D. It depends on the initial velocities of the balls

Correct answer: C

Rationale: In a vacuum (neglecting air resistance), the acceleration due to gravity is constant for all objects regardless of their mass or composition. This means both balls will experience the same acceleration and reach the ground at the same time.

3. Which of the following sentences uses figurative language?

A. The scientist conducted an experiment.
B. The child ran like a cheetah.
C. The book contained many pages.
D. The teacher explained the concept clearly.

Correct answer: B

Rationale: This sentence uses a simile, comparing the child's speed to a cheetah's.

4. The basic unit of communication in the nervous system is called a:

A. Neuron
B. Astrocyte
C. Neurotransmitter
D. Synapse

Correct answer: A

Rationale: The basic unit of communication in the nervous system is a neuron. Neurons are specialized cells that transmit information through electrical and chemical signals. They form complex networks to relay messages throughout the body. Astrocytes are support cells that help maintain the environment around neurons. Neurotransmitters are chemicals that transmit signals between neurons at synapses. A synapse is a junction between two neurons where communication occurs. However, the primary unit responsible for communication in the nervous system is the neuron, making it the correct answer.

5. What is the SI unit of measurement for work?

A. Newton-meter (NÂ·m)
B. Joule (J)
C. Watt (W)
D. Meter per second (m/s)

Correct answer: b

Rationale: Work is measured in Joules (J) in the SI unit system.

6. What is the scientific term for a broken bone?

A. Osteoporosis
B. Fracture
C. Sprain
D. Dislocation

Correct answer: B

Rationale: The correct answer is B: 'Fracture.' A fracture is the scientific term used to describe a broken bone. Osteoporosis (A) is a condition where bones become weak and brittle, increasing the risk of fractures. A sprain (C) is an injury to a ligament, not a bone. A dislocation (D) occurs when the bones in a joint are forced out of their normal position, but it is not the term for a broken bone.