Food takes about 6 to 8 hours to completely pass through the digestive tract.
Answer:
C
Explanation:
During their development, many organisms look similar, suggesting that very different organisms may have a common ancestor. - Think of the human fetal neural / spine development which mirrors other species.
I would say energy myself, and this is because energy plays a key role in all of these. With trophic levels energy is being transferred amongst the levels. Food chain's is a map of how the energy is passed along the chain. Food web is a web of how energy is transferred, and this is why I would say energy is a keyword.
<span>is absorption of nutrients and minerals from food.</span>
Only a fraction of the energy<span> available at one trophic </span>level<span>is </span>transferred to the next<span> trophic </span>level<span>; the fractions can vary between 1-15%, with an average value of 10%. Typically the numbers and biomass of organisms decreases as one ascends the </span>food chain<span>.</span>
