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.
Answer:
the first wave of extinction may be related to rapid cooling at the end of the Ordovician Period, and the second phase is widely regarded as having been caused by the sea-level fall associated with the glaciation.
Water enters the soil in a process called infiltration, and then moves downward through the soil in a process called percolation.
Answer and explanation;
Nucleus; houses a cell's DNA and its processes include protein, replication and packaging for cell division. It is also the site for transcription.
Cytosol; coordinates a responsible to the environment, metabolism and motor proteins.
Endomembrane system; includes the nuclear envelope (surrounds nucleus), rough and smooth ER, golgi body, lysosomes?vacuoles, peroxisome and plasma membrane.
Semiautonomous organelles; mitochondria (animals) and chloroplast (plants) which provide energy for the cell.