Answer:
Organism.
Explanation:
The cell is the smallest form of life. Cells work together to form tissues, tissues work together to form organs, and organs work together to create an organ system, and organ systems work together to create organisms. I believe "organism" includes all of these other levels.
I think the enzyme photolyase is activated by light and can repair thymine dimers caused by UV radiation. Exposure to UV radiation is the main factor that causes skin cells to become cancer cells. These enzymes are involved in the repair of ultraviolet light-induced DNA damage when activated by light absorption.
Answer:
They have helical thickening of lignin in their walls to prevent collapse
Explanation:
the primary function of Xylem and its conducting vessels tracheids is to provide support and tranport water and minerals in plants.
Xylem vessels have layers of dead materials in the walls called LIGNIN. Lignin is a polymer; a very strong, hard materials that stop water passage through it,because it contains dead cells,
Therefore the presence of deposit of these strong impermeable, ligified walls in its walls prevent its collapse during mass flow of water of transpiration pull.
I think it is A to, since the tissues are the closet thing to cell, which microscopic anatomy studies.
