Answer: Layer a is 500 million years old.
Explanation:
Trilobite is a member of the group of extinct arthropods found as fossils and they can be identified by the three-lobed as well as three segmented forms. These were the marine animals. These were appeared initially in the Cambrian Period. They used to live 542 million years ago so the fossils can be estimated to be aged of 500 above years old. These animals used to dominate in the sea area.
Addition, you added an extra T between the first A and C
Aerobic cellular respiration uses O2 to break down glucose molecules into Adenonsine Triphosphate. So yes?
A trait is a characteristic, such as color or size, that is inherited by an offspring from its parents. The genes that control a trait come in pairs, one gene from each parent. We represent these gene pairs by writing a combination of two letters. For example, if one parent contributes a gene for blue eyes (c), and other parent contributes a gene for brown eyes(C), then we write the offspring’s eye color trait as Cc. This combination, of the two genes that determine the trait, is called a genotype. If gene pair contains a dominant allele, the the offspring will show this dominant trait