Answer:
The lung
Explanation:
The model of the respiratory system made by Megan consists of two balloons. The first balloon stretched across the bottom of the bottle represents the diaphragm which contracts and relaxes to allow air in and out of the lungs. The balloon inside the bottle represents one lung.
Breathing in causes the balloon inside the bottle to be filled with air. This is preceded by the expansion of the diaphragm which makes the lungs to be filled with air. Breathing out causes a contraction of the diaphragm thus making the lungs to let out air.
Answer:
Si una reacción química libera energía, se llama reacción exotérmica. El ejemplo más común es la combustión, en la cual la energía se manifiesta en forma de calor y luz. Si, por el contrario, la reacción química requiere energía del medio para efectuarse, recibe el nombre de reacción endotérmica.
Answer:
The DNA is cut using special chemicals called restriction enzymes,.
DNA ligase are used to insert genes and other pieces of DNA into plasmids.
Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
- Chemical changes are not reversible.
- They lead to the production of new kinds of matter
- It involves mass changes
- Requires considerable amount of energy
It changes the rate of growth that cells usually undergo.
