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!
I’m confused of the question your asking,can you give me more details?
Answer:
This question lacks options, options are:
A) cerebral cortex.
B) basal nuclei.
C) sensory pathways.
D) motor pathways.
E) All of the answers are correct.
The correct answer is E.
Explanation:
The cerebral cortex processes and filters its information before passing the most relevant aspects to other regions of the brain. Some of these brain regions, in turn, send information back to the cortex. These loops, known as 'feedback systems', are considered essential for the functioning of cortical networks and their adaptation to new sensory information. Neural circuits must first assess the importance of incoming sensory information and then refine how it is processed in the future. Positive feedback, triggered with the purpose of amplifying the response to the initial stimulus, can be compared to a chain reaction or a vicious circle. Few are the functions regulated by this mechanism; rather it is triggered in pathological situations. It is the system by means of which the organism very rarely regulates any of the bodily functions under normal conditions, making the initial stimulus to be maintained and even increased. This type of mechanism is predominantly present in pathological situations: Its constitutive elements are: stimulus, receptor, afferent pathway, integrating center, efferent pathway, effector and response. The response does not have the ability to satisfy the initial stimulus.
