Answer:
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
Answer: Clostridium botulinium
Explanation:
An anaerobic bacteria is an organism which does not require oxygen for it's survival. It may not survive or die in the presence of oxygen. These bacteria are used for the process of fermentation for the preparation of beverage and dairy products.
Clostridium botulinium is the example of the anaerobic bacteria. It is found in soil or marine environment in the form of spores. This bacteria is rod shaped. It forms the spores when the conditions for survival is poor. It causes a disease called as botulism.
Answer:
False
Explanation:
Scientist believe that the primitive atmosphere lacked free oxygen. Oxygen is a highly reactive molecule that would have made difficult for complex macromolecules to appear and then create life. Rocks from the precambrian period support this theory.
Anaerobic cells appeared first, then photosynthesis appeared filling the atmosphere with oxygen and the aerobic organism develop cellular respiration to obtain energy, a process more efficient than anaerobic respiration.
Answer:
a. Reproduction occurs rapidly
Explanation:
asexual reproduction can occur rapidly, more quickly than sexual reproduction
The DVD experiment worked to prove that spontaneous generation
