While agriculture is the growing of plants as crops and animals for food, biology is the study of life, which broadly divides into plants and animals, according to Reference.com. The two relate closely and intertwine often. The best agricultural practices make use of lessons learned from biology.
The development of agriculture is vital in human history. It allowed early humans to move from nomadic hunter-gatherers and develop homes in one location. As farmers developed the ability to produce food beyond the needs of their families, agriculture gave others freedom to pursue projects that did not involve gathering food. Reference.com indicates there is an ongoing argument that the development of agricultural practices made civilization possible. As farmers planted crops, they learned biology by observation, in terms of what each crop required to thrive and survive.
From a historical perspective, biology finds its start with the early Greeks. Aristotle used observations and classification of animals. However, it was the microscope's invention during the 16th century that helped to broaden and deepen man's understanding of life, including the study of living cells. While Mendel's study of peas led to the modern study of genetics, this area of biology improved crop yield, making agriculture more efficient.