Nitrogen-fixing bacteria are microorganisms present in the soil or in plant roots that change nitrogen gases from the atmosphere into solid nitrogen compounds that plants can use in the soil.
Microscopes made it possible to learn more about single-celled organisms.
The correct answer is B. It has made tetanus a rare disease in the United States. As with other vaccination programs, Tetanus vaccine has had a high success rate in preventing the disease among vaccinated people. Reinforcing the value of vaccines in preventing serious disease.
The answer is b because gametes are sex cells so they allow them to reproduce
