Chapter Seven Vocabulary Test
COMMENT(S):
I received a 100% on the Chapter Seven vocabulary quiz, indicating my mastery of the important terms associated with transport in multicellular plants.
I received a 100% on the Chapter Seven vocabulary quiz, indicating my mastery of the important terms associated with transport in multicellular plants.
Chapter Seven Test
COMMENT(S):
My lack of extensive knowledge surrounding the structure and function of xylem vessels and phloem sieve tubes cost me 7 points of the last question. Upon receiving my test, I went back to my textbook and review this portion of the chapter and learned that although there are several similarities between translocation in the xylem and phloem, there are certain differences that result in their dissimilar structures. Xylem vessels have lignified cell walls, because this means that cells can be dead (entirely empty) which allows water to flow unimpeded. The strength of these walls also provides the xylem with the ability to withstand high tension inside its tubes and prevent buckling. Phloem sieve tubes have living membranes which control the entry or loss of solutes such as sucrose, preventing any leaking. Sieve tubes also possess a thin layer of cytoplasm and have no nuclei to reduce resistance to flow and prevent the loss of the steep, positive pressure gradient.
My lack of extensive knowledge surrounding the structure and function of xylem vessels and phloem sieve tubes cost me 7 points of the last question. Upon receiving my test, I went back to my textbook and review this portion of the chapter and learned that although there are several similarities between translocation in the xylem and phloem, there are certain differences that result in their dissimilar structures. Xylem vessels have lignified cell walls, because this means that cells can be dead (entirely empty) which allows water to flow unimpeded. The strength of these walls also provides the xylem with the ability to withstand high tension inside its tubes and prevent buckling. Phloem sieve tubes have living membranes which control the entry or loss of solutes such as sucrose, preventing any leaking. Sieve tubes also possess a thin layer of cytoplasm and have no nuclei to reduce resistance to flow and prevent the loss of the steep, positive pressure gradient.