A baby's immune system is not fully developed until he/she is about six months-old. In the meantime, pregnant mothers pass immunoglobulin antibodies from their bloodstream, through the placenta, and to the fetus. These antibodies are an essential part of the fetus's immune system. They identify and bind to harmful substances, such as bacteria, viruses, and fungi that enter the body. This triggers other immune cells to destroy the foreign substance.
The nervous system consist of the brain spinal cord and the brain .
Answer:
A zygote can end up with one fewer chromosome than normal because one of the fertilizing gametes was missing a chromosome. This deletion, called nondisjunction, happened while the gamete was forming.
Explanation:
The proteins are called Histone proteins. Chromosomal DNA is packaged such that the strands of DNA are wound around histone proteins and fold into complex ways to form chromosomes. The histone proteins are positively charged proteins that strongly adhere to negatively charged DNA and form complexes called nucleosomes. Each nucleosome is composed of double-helical DNA wrapped.
