Fossilized non-seed vascular plants from the Devonian period have been identified.
<span>The Devonian is an early period and conformity of the Paleozoic Epoch forming from the edge of the Silurian Era.</span>
Answer:
1A - Respiratory = trachea, lungs... however both arteries and veins move oxygen around the body, and are therefore valid answers
1B - Skeletal = bones
1C - Muscular = muscles
1D - Digestive = stomach, large/small intestine
1E - Circulatory = heart, veins and arteries
2. Cellular respiration is the conversion of sugar into energy the cell uses to function via various chemical reactions. Digestion is an example of this. Stomach acid breaks down food into sugars that cells break down further into energy to keep you alive
3. Bones contain bone marrow deep inside of them which is responsible for the creation of red blood cells. Your lungs can move air all they want but would be useless without red blood cells to take the oxygen to cells and take the CO2 away from them.
Answer:
D
Explanation:
If a group of organs working together is called an organ system, and there are about 11 major body systems including the nervous system, the nervour system must be an organ system.