Bacterium -

Certain bacteria in soil convert atmospheric nitrogen into a form plants can use to grow.

Common forms include cocci (spherical), bacilli (rod-shaped), and spirilla (spiral). bacterium

Bacteria are microscopic, single-celled organisms that exist in virtually every environment on Earth, from deep-sea vents to the human digestive tract. They are , meaning they lack a nucleus and membrane-bound organelles. While often associated with disease, the vast majority of bacteria are either harmless or essential to life. 1. Structure and Classification Certain bacteria in soil convert atmospheric nitrogen into

Scientists use a Gram stain to classify them. Gram-positive bacteria have a thick peptidoglycan layer that retains purple dye, while Gram-negative bacteria have a thinner layer and an outer membrane, appearing pink. and spirilla (spiral). Bacteria are microscopic

Bacteria play a critical role in maintaining the planet's balance: