<span>Silicon dioxide
forms the cell walls of diatoms. These diatoms are a group of algae.
Phytoplanktons are the most common types of diatoms that are unicellular. These
organisms can form colonies in the shapes of filaments or ribbons, fans,
zigzags, and stars that are perfect for monitoring environmental conditions,
particularly water quality in the past and present. </span>
They study the human body
Cell Theory #1Cells are the basic structure and function of a living thingCell Theory #2All organisms (living things) are made out of cellsCell Theory #3<span>only existing cells can make new cells</span>
An enzyme works like a key to a lock. If it finds the right thing it can work.
Hope it helps.
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.