Answer: Option A "Choroid plexus".
Explanation:
Cerebrospinal fluid can be defined as the fluid that is found in the brain and spinal cord of human beings. It is a clear and colorless fluid.
The production of cerebrospinal fluid takes place by the specialized ependymal cells that lies in the choroid plexuses which is present in the ventricles of brain.
The amount of cerebrospinal fluid in a day is 500mL. This fluid acts as cushion that protects the brain from mechanical and immunological protection.
Hence, the correction answer is option A
Answer:
Sarcomere
Explanation:
A myofibril or muscle fiber under an electron microscope shows alternate light band and dark bands. These bands give the skeletal muscle and cardiac muscle a striated appearance. The light band is called the I- band or isotropic band, and the dark band is known as A- band or anisotropic band. In the center of the I-band Z-line is present. It is discovered from a German term Zwischenscheibe (between the disc). The portion of myofibril between one Z-line to the next Z-line is called sarcomere.
I think its free nitrogen
