The tissue that consists of a single layer of elongated (tall) cells whose nuclei are usually at about the same level, near the basement membrane, is epithelium.

The tissue that consists of a single layer of elongated (tall) cells whose nuclei are usually at about the same level, near the basement membrane, is simple columnar epithelium.

1. Identify the type of tissue: The question describes a tissue with a single layer of elongated cells.
2. Determine the cell shape: The cells are elongated (tall), which indicates they are columnar.
3. Check the arrangement of nuclei: The nuclei are at the same level, near the basement membrane, which is characteristic of simple columnar epithelium.
4. Confirm the type of epithelium: Since it is a single layer of cells, it is classified as "simple" epithelium. Combining this with the columnar shape, the tissue is identified as simple columnar epithelium.

The tissue you're referring to is called "Simple Columnar Epithelium". This type of tissue is made up of a single layer of tall, cylindrical cells, with the nuclei typically located near the basement membrane. It is commonly found in areas of the body where absorption and secretion occur, such as the lining of the stomach and intestines.