Answer:
4. The suspected causative agent must be isolated from the diseased host and grown in pure culture
Explanation:
Robert Koch (1843-1910) was one of the most important bacteriologists of all time. Famous for discovering the tuberculosis bacillus (precisely on March 24, such as today, in 1882), he also discovered the cholera bacillus and is considered the founder of bacteriology. He worked on the isolation of infectious agents and reinfections from pure cultures, experiences from which he established the "Koch Postulates".
These postulates have been taken as a reference that describes the etiology of all the causative agents of an infectious disease, although they were originally used to describe only the tuberculosis bacillus. They are the following:
1- The agent must be present in each case of the disease and absent in the healthy.
2- The agent should not appear in other diseases.
3- The agent must be isolated in a pure culture from the lesions of the disease.
4- The agent has to cause the disease in an animal that can be inoculated
Definite volume is doesn’t possess a definite volume so therefore the answer is c
ocean - Large bodies of water
current flowing towards equator carry cold water from poles
current flowing away from equator carry warm water from poles
Ex - Humidity
Think of blood as a gas/ fuel for the car ( your body). If there is no fuel, there's no movement (dead) so when the fuel tank is damaged the car won't function properly.
So if the heart becomes damaged, or weakened it would start making blood clots and damage the organs that need blood to function properly. The circulatory system wouldn't function properly and because other organs depend on the circulatory system it would cause a chain reaction, affecting other body systems. <span />
