Question

What connects the two hemispheres of the brain?
A. Grey Matter
B. Corpus callosum
C. White matter
D. Thalamus

Answer 1

Hint: The cerebrum is that portion of the brain that consists of two hemispheres. It is the main part of the forebrain or prosencephalon and also forms the major part of the brain. It contains many lobes and is associated with many functions such as coordination of motor areas, memory, and communications, etc.

Complete answer:
Now we shall note down some important points about the cerebrum:
The cerebrum forms the major part of the human brain.
It consists of two distinct regions- The cerebral cortex (appearing grey in color) and the inner cerebral white matter.
The cerebral cortex contains a number of folds on the surface. The folds are known as gyri or convolutions. The deepest grooves between such folds are known as fissures, and shallower grooves between folds are termed sulci. The most prominent of these is the longitudinal fissure that divides the cerebrum into left and right hemispheres. The two parts are interconnected with each other with CORPUS CALLOSUM.
A large number of neurons (the cell bodies of neurons) are concentrated in the cortex region that gives the grey color to it (GREY MATTER).
The fibers of the tracts (the axons of the neurons) are myelinated which gives a whitish appearance to the inner part of the cerebrum (WHITE MATTER).
The cerebral cortex contains motor areas, sensory areas, and some large regions that are neither completely sensory nor motor. Such regions are known as Association regions that are responsible for intersensory associations, memory, and communications.
The cerebrum wraps around a structure called the thalamus which is often regarded as the relay center of the brain. It is the major coordinating center for motor and sensory signaling.

Note:
Only the cell bodies of the various neurons are concentrated in the cerebral cortex region. The axons of those cell bodies are in the white matter regions. Some of the neurons have their cell bodies in the brain but their axons are long and may pass down into the vertebral column or spinal cord.