NEET Class neet Answered

(i) Obligate aerobe: These are aerobic bacteria which grow exclusively in the presence of molecular oxygen and fail to survive in its absence, e.g., Bacillus subtilis, Azotobacter.

(ii) Facultative aerobe/anaerobes: These are aerobic bacteria which can also survive in absence of oxygen, e.g., Klebsiella, Pseudomonas.

(iii) Obligate anaerobe: These are anaerobic bacteria which grow and multiply in the absence of free oxygen. They fail to survive under aerobic conditions, e.g., Clostridium botulinum.

(B) Yes, Salmonella typhi is a facultative aerobe.

(C) Red sickness is a form of sickle cell anemia which is an inherited form of anemia.  In sickle cell anemia, the red blood cells become rigid and sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body.