Meninges refers to the three layes of membranes surrounding the brain and spinal cord of the mammals. The inflammation of these protective membranes of the brain and the spinal cord caused by the infection of bacteria, virus or other microorganisms is called the meningitis.
A laboratory test to identify or rule out meningitis is the analysis if the cerebrospinal fluid (CSF) by lumbar puncture. CSF is a colorless fluid filling the ventricles of the brain and the central canal of the spinal cord. Lumbar puncture is a techinque of isolating the CSF from the sac sround the spinal cord using a needle under a local anesthetic. The sample is then analysed for the opening pressure which is normally between 6 and 18 cm of water in a patient who is not infected with meningitis. Also, the levels of glucose in CSF is above 40% of that in blood in non-infected persons. If lactate levels are less than 35mg/dl, this will also rule out meningitis.
Answer:
<u><em>The correct option is C) genetic variation</em></u>
Explanation:
Genetic variation can be described as the differences present in the genetic material i.e DNA of organisms present in a population. Genetic diversity allows organisms of a species to better adapt to an environment. A population in which the genetic variability is scarce might become wiped out by a disease or an invading predator.
As the birds show different variations hence the term that best described them is genetic variation.
