False. Their exoskeletons are made of silica.
Answer:
science is different from many other ways of learning because of the way it is done. Science relies on testing ideas with evidence gathered from the natural world.
Hope this helps
Answer:
Environmental factors such as diet, temperature, oxygen levels, humidity, light cycles, and the presence of mutagens can all impact which of an animal's genes are expressed, which ultimately affects the animal's phenotype.
Explanation:
The changes that occur in body size, proportions, and skeletal maturity during the middle childhood include; Bones continues to strengthen and broaden, permanent teeth replace the primary teeth, normally a third of school age children suffer from malocclusions, making braces common by the end of elementary school. Additionally, the children's growth is slow and regular though large individual and ethics variations exists in the physical growth. <span />