Activities

1. Define system (in relation to Science).
   
   
2. Identify an organ in the digestive system and explain its role in the digestion process.

3. Describe how two simple machines work together to function a complex machine.
   
   
4. Describe the relationship between the Sun and the Earth in the solar system.

5. Describe how two of the body’s systems work together to sustain life in a human.
   
   
6. Describe how the processes related to the water cycle function together to recycle water naturally on Earth.

Answer Key/Rubric

1. A system is a set of connected things or parts forming a complex whole.
   
   
2. Acceptable responses may include, but are not limited to:

• Stomach: holds food, secretes enzymes which further break down food
• Small intestines: breaks down food even more using enzymes secreted by the pancreas and bile from the liver
• Large intestines: passes waste from the digestive process for elimination through the colon

3. Acceptable responses must include: identification of two simple machines, description of how these work together to make a complex machine
   Sample response: A wheelbarrow is made up of a wheel and axel and a lever. The lever decreases the force required to lift the load which the wheelbarrow is transporting. The wheel/axel system allows the load to be moved with less force than would be required to manually carry it.

4. Acceptable responses may include, but are not limited to:

• The Earth revolves around the Sun
• The Sun provides warmth for the Earth
• The Sun provides energy needed for plants to grow, which provides food for other living organisms
• The Sun provides natural light in the day time

5. Acceptable responses must include: reference to two body systems and how they interact to maintain life
   Sample response: The circulatory system controls the blood flow in our body, and the respiratory system involves breathing and delivers oxygen to our bodies.  They work together because the lungs (respiratory system) oxygenate the blood, which travels throughout the body providing cells with oxygen needed to sustain life.  The circulatory system, powered by the heart, is responsible for allowing this transport to occur.

6. Sample response: The sun evaporates water, turning from a liquid to a gas. As the water vapor cools, it condenses to form clouds. When the clouds are saturated, they form precipitation, in which moisture is transported to the surface of the Earth in forms such as rain, hail, sleet, or snow.  When it precipitates, water accumulates in rivers, lakes, oceans, puddles, etc. and the process repeats itself. These processes naturally maintain and recycle the supply of water we have on Earth.