Reproduction, Heredity, Variety in fitness of population, and variety in characters among the population are all four conditions for natural selection.
Answer:
The correct option is A.
A. blocking transmission of impulses from the spinal cord to thalamus
Explanation:
Local anesthetics, like lidocaine and novocaine, reduce the perception of pain by blocking transmission of impulses from the spinal cord to thalamus because local anesthetics they first bind to ion channel in the nerve cell and then inhibit function of the ion channel present in the membrane of nerve cell known as sodium channel. This later cause blockage of nerve impulses at the site where the injection was given from the spinal cord.
