<span>There wasn't many vaccinations back in the day and medicine slowly developed through years passing by. Also eras such as the Black plague and others really helped develop medicines and vaccinations moving forward for people to use.
Hope this helps.</span><span />
Answer:
Each cell expresses, or turns on, only a fraction of its genes. The rest of the genes are repressed, or turned off. The process of turning genes on and off is known as gene regulation. ... Gene regulation also allows cells to react quickly to changes in their environments.
Answer:
Improved agricultural practices have led to increased productivity, decreased organic production, increased health risks, increased water pollution, and increased profits.
Explanation:
Since the turn of the 20th century, agriculture has experienced numerous changes and is much different nowadays than it used to be. This has been due to rapid technological development, which has also improved agricultural practices. The improvements have been in every sphere, from the protection of the plants to create more resistant and plants that have higher productivity, better irrigation, mechanization, bioengineering, and at the end of it all it has led to higher profits.
The developments in genetics have led to the creation of plants that are more resistant to diseases and have higher productivity. The pesticides, herbicides, and fungicides have all helped in the protection of the pants and destruction of pests, which further led to an increase in production, but their usage has also led to pollution of the soil and water. Unfortunately, the usage of chamicals has led to increased health risks, and significantly lowering the organic production which was dominating before.
