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.
Answer:
A multicellular organism develops from a single cell (the zygote) into a collection of many different cell types, organized into tissues and organs.During development, cells use both intrinsic, or inherited, information and extrinsic signals from neighbors to "decide on" their behavior and identity.
Answer:
a. a disease
Explanation:
Pathogens are disease-causing organisms. For example, some bacteria and viruses are pathogens for different species.
Therefore, a tree with pathogens present is likely to have a disease. Different pathogens affect different trees. Examples include Anthracnose
, which is caused by a fungus
