Effective Answers
It is important to use detail, correct terminology, and grammar to effectively communicate your ideas through writing. In order to demonstrate effective written responses, this page contains actual
errors is a summary and/or listing of errors including style, content, etc.Better answer follows the same form or style of the student's answer but contains revisions/corrections that improves clarity and effectiveness of the answer. The main focus is to correct gross errors in spelling, grammar, punctuation, and terminology.
Preferred answer focuses on detail, terminology, form, and style -- the kind of answer Mrs. Lant would like to see
Original question
Why was it necessary to rinse the outside of the dialysis tubing before placing it in the
distilled water?
Student's answer
B/c it rinses it off and makes it clean so it doesn't contaminate the water
Explanation of errors
The word "it" is used 4 times and stands for 3 different
nouns. There is no period at the end of the sentence. The sentence started
with "B/c," which is appropriate for note-taking, but not for graded, written
answers (the word "because" should be used). Also, the author of the
sentence needed to make clear where the water was that could be contaminated (inside the
beaker, but outside the cell).
Better answer
The water rinses off particles left on the tubing that could contaminate the water in the beaker.
Preferred answer
It is necessary to rinse the dialysis tubing before placing the tubing in the distilled
water to ensure that no starch or dextrose solution remains on the outside. Any
remaining solution could contaminate the water outside the beaker and change
(skew) the lab
results.
Original
question
Osmosis occurred during this experiment. In which direction did it occur and how do
you know?
Student's answer
It went From Outside to inside the cell.
Explanation of errors
Capital letters are used within the sentence. The student's
answer does not explain "It". Also, the student did not answer
the second part of the question, "...how do you know?".
Better answer
Water moved from the outside of the cell to the inside.
Preferred answer
Since the cell was placed in a hypotonic solution, water moved from the outside of the
cell to the inside. Also, the cell expanded as a result of water diffusing
into the cell.
Original
question
Osmosis occured during this experiment. In which direction did it occur and how do
you know?
Student's answer
the iodine went into the cell
Explanation of errors (style, content,
etc.)
The
"t" in "the" is not capitalized; no period at end of sentence.
In the question, it is stated that osmosis occurred. Osmosis is the diffusion of
water; therefore, the question is only asking about the diffusion of water. The
student's answer is not only incomplete (not answering the second half of the question),
but shows lack of understanding of Osmosis, the diffusion of water, not iodine.
Better answer
Water moved from the outside of the cell to the inside.
Preferred answer
Since the cell was placed in a hypotonic solution, water moved from the outside of the
cell to the inside. Also, the cell expanded as a result of water diffusing
into the cell.
Original
question
Intravenous solutions must be prepared so that they are isotonic to red blood cells.
A 0.9 percent salt solution is isotonic to red blood cells. a) Explain what will
happen to a red blood cell placed in a solution of 99.3 percent water and .07 percent
salt.
Student's answer
it will be hypotonic
Explanation of errors
Better answer
The solution is hypotonic to the red blood cell.
Preferred answer
