It has two layers.
Hope I could help :)
Answer: 1000 nm
Explanation:
Bacteria are the type of biological cell. They constitute a large domain as they are found every where on the earth.
These are few micrometer in length which means 200-700nm . It depends on the type of the bacterial cell. The bacteria are the first organism that appeared on earth.
They are found in water, on land, desert, hydro thermal vent, snow et cetera. These are variable in shape.
The correct answer is B. Pinna because auris externa is the external portion of the ear, which is called auricle ( also known as pinna ).
* Hopefully this helps:) Mark me the brainliest:)!!
<em>∞ 234483279c20∞</em>