The main difference between homologous structures and vestigial structures is that homologous structures are the similar anatomical structures inherited from a common ancestor whereas vestigial structures are the anatomical structures which have reduced their size as they are no longer used.
Epithelial tissue is composed of the innervated and avascular layer of cells which are tightly packed. It forms the outermost layer of the body and protects the internal layers and organs.
This tissue can be classified into different categories based on the shape of its cell, and the total number of the layers.
The epithelial tissue with only one layers is known as the simple epithelial tissue.
The epithelial cells that are thin, flat, and scaly are known as the squamous cells.
While the cubodial cells are round or square in shape.
Hence, the given blanks can be filled with classified, simple, squamous, and square.
<span>C. Cells, Tissues, Organs, Organ Systems
The answer is C. Cells are the fundamental unit of life. Without them, life would not possibly exist. Well that is according to the cell theory, which states that cells are the basic unit of life, cells came from pre-existing cells and cells make up living organisms.
</span>
Answer:
Charles Darwin was best known in the 19th century
Explanation: