The appearance of fossils would the the answer.
Although there has been some scientific debate about what fossil strata should mark the beginning of this period, the "International Geological Congress" determined that the Cambrian period was approximately 543 million years ago of which the first appearance in the fossil record of worms that made horizontal burrows was discovered.
The answer is the endogenous opiate.
The human body naturally produces its own opiates like substances and uses them as neurotransmitters. These substances include endorphins, enkephalins, and dynorphin, often collectively known as endogenous opioids. Endogenous opioids modulate our reactions to painful stimuli.
During dormancy, seeds wait until the conditions are optimal for cellular respiration. Modifications would include things such as seeding elongation, germination and hormone regulation
Answer:
Erythrocyte
Explanation:
Erythrocytes, or otherwise called, red-blood cells are responsible for transporting oxygen and carbon dioxide to and from the cells and tissues. The reason for this is because of a protein called hemoglobin. The hemoglobin found in erythrocytes allow for transportation of oxygen + CO2 to and from cells.
I think the answer is A
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