Prokaryotes are decomposing bacteria that can be found in air, soil, and water. They replicate their DNA through binary fission and some secrete toxins. Prokaryotes like eubacteria and archaea lack nuclei in their cells and have peptidoglycan in their cell walls. Gram-positive bacteria are generally more resistant to antibiotics than gram-negative bacteria. Prokaryotes can take different shapes and form capsules in harsh conditions.