You are given a sample of plant tissue and asked to identify the type of tissue and its location in the plant. Using your microscope, you notice two distinct layers of cells. One layer contains cells that are tightly compacted together while the other layer has loosely arranged cells. The cells in both layers contain many chloroplasts. Based on this information, you determine the tissue is

Question

A.  mesophyll tissue from a leaf.
B.  ground tissue from a stem.
C.  vascular tissue from a leaf.
D.  mesophyll tissue from a stem.
E.  vascular tissue from a root.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

Gather Content
· What do you already know about  the shape, characteristics, and arrangement of plant cells? How does it relate to the question?

Consider Possibilities
· What other information is related to the question? Which information is most useful?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  mesophyll tissue from a leaf.

Clarify Question
· What is the key concept addressed by the question?
        o Plant tissue can be specifically identified by using a microscope and examining the shape, characteristics, and placement of cells.
· What type of thinking is required?
        Apply, because you must remember what you know about plant tissues, and then apply it to an unknown sample
· What key words does the question contain and what do they mean?
        o Chloroplast, which is the organelle in which photosynthesis occurs.
        o Loosely arranged cells, which can have a spongy appearance andin plants can refer to a specific mesophyll.
        o Compacted cells, which can refer to a specific type of mesophyll.

Gather Content
· What do you already know about  the shape, characteristics, and arrangement of plant cells? How does it relate to the question?
        o Mesophyll tissue has spongy and a compact (palisade) layers in eudicots.
        o Chloroplasts are found throughout the mesophyll.

Consider Possibilities
· What other information is related to the question? Which information is most useful?
        o Vascular tissue would have bundles of xylem and phloem, and would not have chloroplasts.
        o Ground tissue would have parenchyma, sclerenchyma, and collenchyma

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o To answer this question, you need to recall the cellular characteristics of each of the major tissue types of a plant.
        o Focusing on the presence of chloroplasts, as well as the spongy and compacted cell layers, leads to only one conclusion
        o The presence of the spongy and compact layers with chloroplasts is sufficient to determine this is mesophyll.

Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
· Apply level:
        o This question asked you to identify cells in plant tissue.  Answering this question correctly depended on your ability to use your knowledge of cells and tissues in a new situation.  If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you remember that mesophyll has spongy and compact layers, or thatchloroplasts are plentiful in mesophyll? Did you have trouble extending your knowledge of plant tissues to determine the correct answer?