Cyanobacteria were very simple organisms and performed were an role in changing Earth's early atmosphere. They carried out photosynthesis to produce the materials they needed to grow. In this process, they release Oxygen which is needed to sustain life on Earth for Humans and other organisms.
<span>The central nervous system
consists of the two major structures: the </span><span>brain <span>and </span></span>spinal cord. The brain is encased in the skull, and protected by the
cranium.[7]<span> <span>The spinal
cord is continuous with the brain and lies </span></span><span>caudally <span>to the
brain and is protected by the </span></span>vertebra. These are
connected by nerve to send signals. So a tract is not part of the central
nervous system.
Answer: This statement ("antibiotics kill bacteria so they must kill healthy human cells too and they must be avoided at all costs!") is wrong and can be proven to be so in the following explanation about the mode of actions of antibiotics.
Explanation:
Antibiotics are drugs which are used for the treatment of diseases caused by bacteria microorganisms. According to their mode of action, they can either be bactericidal or bacteriostatic.
Bacteriostatic antibiotics work by binding to enzymes needed by bacteria to build proteins essential for their own growth and reproduction. Atypical example is the antibiotics, sulfonamide. This drug acts by inhibiting a critical enzyme called dihydropteroate synthase which are specific to the metabolic pathway of the bacteria cells for the synthesis of folic acid. This causes the bacteria to stop growing. Together with the actions of the immune system, the bacteriostatic actions of the antibiotics can effectively stop am infection without affecting the host cells.
