Download Open Response Questions – Answers

Name _______________________________________
Biology MCAS Prep
Session 5: Open Response Questions
Date _____________
Today’s class will focus on OPEN RESPONSE QUESTIONS!
Do Now:
1. Write the equation for cellular respiration!
Glucose + Oxygen  Water + Carbon Dioxide + ATP Energy + Heat
2. Write the equation for photosynthesis! (Hint: it is basically the cell respiration equation in reverse.)
Water + Carbon Dioxide + Sunlight Energy  Glucose + Oxygen
3. Of the two processes above, animals only do _____________CELL RESPIRATION________________.
This means that they breathe in ______________OXYGEN____________ and breathe out
_______CARBON DIOXIDE____________.
4. Plants do both of these processes, but they do more _______________PHOTOSYNTHESIS________.
This means that they take in __________CARBON DIOXIDE______________________ and release
________OXYGEN____________.
5. Look at the question on the next page. At first glance, what looks challenging, intimidating,
annoying, or scary about it?
Now, wait for a quick class discussion…
Strategies for doing Open Response Questions:
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Underline key words that help you understand what the question is asking about
Circle the “direction words” that tell you what you need to do (e.g. describe, explain, identify, label)
Look carefully at pictures, diagrams, etc. – annotate these with margin notes if it’s helpful
Make notes or an outline in the test booklet
Answer each part of the question separately (a, b, c, etc.) and completely
When done, read back over the question and your answer to see if you’ve included everything and
been as clear as possible. Add details and explanations!
(Anything else students come up with is good too)
Question 1:
Answer:
Flask 1 – Blue. Level of carbon dioxide would be decreasing. The plant is doing photosynthesis which
uses up carbon dioxide and produces oxygen.
Flask 2 – Yellow. Level of carbon dioxide would be increasing. Fish are doing cell respiration which
releases carbon dioxide, which would turn the water yellow.
Flask 3 – Pale yellow or green (or blue with good reasoning). Fish are releasing carbon dioxide through
cell respiration (which would turn the water yellow) but the plant is absorbing some/all of that carbon
dioxide for photosynthesis, preventing the water from turning as yellow as Flask 2.
Flask 4 – Blue. Nothing is in it to change the carbon dioxide levels.
Question 2:
The drawing below represents an organism that a student observed when examining a
sample of pond water with a light microscope.
The student identified this organism as a prokaryote.
a. Is the student's identification accurate? Explain your answer using information from
the diagram.
b. Identify three similarities between the cells of prokaryotes and eukaryotes.
Answer:
a) No, the student is not correct. The organism is a eukaryote because it has a nucleus.
b) Prokaryotic and eukaryotic cells both have
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cell membranes around the outside
ribosomes for making proteins
cytoplasm filled with water, enzymes, nutrients
DNA (but not necessarily inside a nucleus)
Question 3:
Answer:
a) Molecular evidence means DNA or protein sequences.
Scientists would get the gene or protein sequences from both plants.
They would then compare the nucleotide or amino acid sequences and count the number of
differences between the sequences of the two species.
The more differences, the less closely related two species are. So there must have been many
differences in the gene sequences of these two plants.
b) The two plants evolved similar features because they evolved in the same type of environment.
Natural selection makes populations evolve traits that are helpful for survival in their particular
environment.
Since both plants live in the same environment (desert) the same traits are helpful for them.
c) Specifically, all of their traits relate to conserving water:
 Small leaves prevent too much water from evaporating into the dry desert air
 Prickly spines prevent thirsty animals from chewing on the plants
 Thick fleshy stems can store lots of water