1. The cell wall has lignin (hard substance): to prevent the xylem vessel from collapsing and withstand high pressure.
2. The absence of protoplasm (nucleus + cytoplasm) and cross wall: to allow water to move through the lumen easily.
Hope it helped!
Explanation:
it's very reactive which helps to make strong bones
The answer for the above question is Mutation.
Mutations are random spontaneous changes that occur suddenly in the DNA. A single mutation can have a large effect, however in may cases evolutionary changes are based on the accumulation of many mutations. The gene flow is any movement of genes from one generation to another and is an important source of mutation
Five conditions<span> are required in order for a population to remain at </span>Hardy-Weinberg equilibrium<span>: A large breeding population. Random mating. No change in allelic frequency due to mutation.</span>