|
|
|
|
|
These Biology Open Response Questions are from previous Science MCAS. The questions were released by the Department of Education.
The first two Open Response Questions do not have sample answers. All others have answers that were graded as 4 Points through 1 Point.
Before writing your answers, do the following:
1) What basic items do I know about the subject of this question - Make a list of words that you might want to use in your answer. Remember, you might not actually use all of these words but it is better to have them in front of you before you start writing.
2) What actual questions are being asked? How many actual answers are required? Underline the actual questions.
3) Without thinking about an actual answer, decide how each answer should begin. For example, if the question asked "How many little pigs did the Big Bad Wolf chase?" Your answer would start "The number of pigs that Big Bad wolf chased was ........."
When you have done #1-3 above, then write your answer to the question. Finally, read your answer to see if a) it makes sense b) it answers all the questions asked
***********************************************************************
Question #1- Examine the following sequences of DNA
W represents a normal strand of DNA. X,Y and Z represent potential mutations of W. Identify the type of mutation for each strand (X,Y,Z). Which mutation has the least effect on the organism? Explain why.
***********************************************************************
Question #2- A scientist observed the following changes that occur to cells of Elodea and to a red blood cell placed in various solutions. The table below shows the observations.
Pick two solutions for Elodea and two solutions for the red blood cells and explain what happened in each case.
|
Pond Water |
Distilled Water |
1% Salt solution |
3% Salt solution |
|
|
Elodea cell |
No Change |
No Change |
Cell shrivels |
Cell shrivels |
|
Red Blood cell |
Cell bursts |
Cell bursts |
No Change |
Cell shrivels |
The following questions contain actual answers given by students (misspelling included) and the number of points that the answers received. Four points is the highest grade given.
Question #3- A friend says that one of the problems with using fossil fuels is that oxygen is used in the combustion reaction. If we keep using fossil fuels, your friend argues, all of earth's oxygen will eventually be gone. Using scientific principles, explain why your friend's statement is incorrect. Be sure to include photosynthesis and the Law of Conservation of Matter in your explanation.
Four Point Answer
He is incorrect because the Law of Conservation of matter says that matter cannot be created or destroyed, only converted. So the amount of oxygen will always be the same. Also, in photosynthesis, plants take in CO2 and release O2. So when fossil fuels are combusted, you get CO2, the plants, in turn, will take that in and release O2 into the atmosphere
Three Point Answer
This person is wrong in their belief that the earth will run out of oxygen. In this process of using fossil fuels, the oxygen is not destroyed. The Law of Conservation of Matter states that matter cannot be created or destroyed by ordinary means. Even though oxygen is used in the combustion process, it is not destroyed because it is matter.
Another reason that the earth won't run out of oxygen is that plants are constantly undergoing photosynthesis. During photosynthesis plants take in carbon dioxide and give off oxygen. Oxygen is constantly being produced by plants and this is why the earth will never run out of it.
Two Point Answer
My friend's statement is incorrect because even though oxygen is used in the combustion reaction, oxygen is always going to be there. It will never go away. There will always be enough oxygen for everyone and everything. One reason for this is photosynthesis, As green plants take in carbon dioxide, they give off oxygen which accounts for some of the available oxygen. So by this explanation, my friend must be wrong.
One Point Answer
When a tree goes through photosynthesis, the waste is oxygen so that the supply would be replenished. The only thing is that if the pollution were to kill the trees we would loose a oxygen supply.
***********************************************************************
Question #4 - Animals and plants in New England adapt to the environmental changes that accompany the transition from summer to fall.
a. Describe two of the environmental changes that accompany the transition from summer to fall in New England.
b. Identify and explain three ways in which living organisms in this ecosystem adapt to these seasonal changes in the environment. Include at least one plant and one animal adaptation.
Four Point Answer-
a) One environmental change is the weather cooling off. The temperature doesn't get as high during the day and it's colder at night. Another change is the sun is not up as long. The days start to get shorter.
b) The birds adapt by going south during the winter months to the
warmer air. Butterflies also do the same thing.
Trees lose their leaves during the winter months so that they don't
have to provide food for the entire tree. Less energy loss. Bears
also go into hibernation for the winter so that they don't have to
find food or bear the cold.
Three Point Answer
a. The environmental changes that accompany the transition from summer to fall is the temperature change. It gets a lot colder in New England and animals have to get bigger coats and get ready to hibernate for the winter. Another is days become shorter. Plants have to drop their leaves in order to save energy in the short sunlight. Animals have to hunt for food and quicker if they are not nocturnal.
b. A tree will drop its leaves to save energy. A squirrel stocks up on food well before the fall and winter comes. And birds will fly south to where it is warm and there is plenty of food.
Two Point Answer-
a. One example would be that that the animals grow a thicker coat of fur. Another example could be that their coats turn a different color to adapt to their environment.
b. During the winter some rabbits fur changes to white so that they blend in with the snow and aren't so easily preyed on. Trees lose their leaves in the fall. And some animals like bears hibernate for the winter
One Point Answer
The leaves start to fall and the temperature drops
**********************************************************************
Question #5 - If you place a wilted lettuce leaf in a pan of tap water for an hour, the lettuce leaf will become crisp again. Explain in detail why this occurs. Be sure to include hypotonic, osmosis, central vacuole, cell wall, and turgor pressure in your explanation.
Four Point Answer
If a wilted leaf is placed in a pan of water for an hour, it will become crispy again. The leaf is wilted because it has no water in it. When the leaf is placed in water the process of osmosis takes place in which the water moves from the pan into the leaf. The water is a hypotonic solution and wants to move into a hypertonic solution which is the leaf. The water is allowed through by the cell wall and then stored in the central vacuole When the central vacuoles are filled up they stretch out by force of water. These vacuoles then press against the cell wall creating a pressure that is called turgor pressure. This turgor pressure is then what causes the wilted plant to become crisp again.
Three Point Answer (there were some lousy diagrams with this answer)
Wilted cells lack water creates hypotonic cells water enters the cells by osmosis. The central vacuole is filled and the cell wall becomes crisp again.
To explain how the lettuce crisps, the state of the wilted cell must be explained. When a plant has wilted it means that there is not enough in the central vacuole and thus, the cell wall is not taught but flaccid
When it is place in the pan of water, water rushes into the cell by osmosis because the cell is hypertonic and the water is hypotonic. The water enters the central vacuole and enlarges it. This makes the cell wall tight and crispy.
Two Point Answer
Hypotonic means that the lettuce had less concentration of solutes and more concentration of water which means eventually the water will move into the cell. The water will move into the cells by osmosis. The cell is also surrounded by its cell wall. The cytoplasm and plasma forces themselves against the cell wall making it stiff. That is how the lettuce regains to be crisp again.
One Point Answer
When placed in a pan of water for an hour, a wilted lettuce leaf will become crisp again because of osmosis The water enters the cell wall through the central vacuole. It causes the wilted piece of lettuce to gradually become crisp again.
************************************************************************
Question #6 - Study the diagram below. It represents a container that is divided by a semi-permeable membrane. A different solution in its initial state is shown on each side of the membrane.
a) Describe which molecule(s) will move through the membrane and which molecule(s) will not
b) Describe the relative rates at which the molecule(s) will move across the membrane
c) Describe in which direction the molecule(s) will move
d) Describe how long the molecule(s) will continue to move
Four Point Answer
a) Substances A and B will move through the membrane because they have small molecules. Substance C is a larger molecule and will not be able to diffuse though the semi-permeable membrane.
b) Substance A will be able to diffuse through the membrane faster than substance B because it is a smaller molecule.
c) Substance A will diffuse from side 2 to side 1 because side 2 has a higher concentration of substance A. Substance B will diffuse from side 1 to side 2 because there are no molecules of substance B on side 2. Therefore side 1 has a higher concentration.
d) The molecules of substance A and B will continue to diffuse through the membrane until they reach equilibrium, an equal amount of each substance on each side of the membrane. They will continue to move across but equal amounts will diffuse in both directions in order to maintain equilibrium.
Three Point Answer
a) Molecules of substance A and B will move through.
b) The molecules of substance A will move the fastest because they are the smallest. The next fastest are molecules of substance B.
c) Molecules of substance A will move to side1. Molecules of substance B will move to side 2.
d) The molecules will continue to move until there is a balance between both sides
Two Point Answer
a) The molecules that will move across the membrane are substance A and B but C will not.
b) Substance A will move across the membrane quickly but because it is larger, substance B will move relatively slowly.
c) Side 1's molecules will move into side 2.
d) They will move until all the molecules on side I have reached side II
One Point Answer
a) Substance A and B will fit.
b) Relatively fast
c) Both in opposite directions
d) Until all the same are together.
***********************************************************************
Question #7 - Potato plants can be grown from potato seeds that form from the flowers that bloom on the potato stems. Potato plants can also be grown from pieces of potato that grow sprouts.
a) Explain what the difference is in the genotype and phenotype of the plants grown from these two different reproductive processes.
b) Give one advantage of each process
Four point answer
A. If a potato plant is grown from potato seeds that form from the flowers that bloom on potato stems, this plant would have a different genotype and possibly phenotype that of the "parent" plant. This is because pollen from another plant would help form the seeds and so the genetic makeup of the plants formed from seeds would be different. If a potato is grown from pieces of potato that grow sprouts, it will have the same genotype of phenotype of the original potato did because it produced asexually, there is only one parent.
B. An advantage to growing a potato from seeds is that the potatoes will have a lot of variation. One advantage to growing a potato from a potato plant that has grown sprouts is if the potato was large chances are the new ones would be too.
Three point answer
A. The potatoes grown from seeds will all have different genotypes and phenotypes. The potatoes grown from sprouts will have the same phenotypes and genotypes as the potato that the sprouts came from.
B. An advantage to growing the sprouts is any desired characteristics of the potato that the sprouts came from will be in the new potatoes. The advantage to growing the potatoes from seeds is a variety of different plants will be produced and the desired ones can be kept.
Two point answer
A.The genotype differences is that the potato grown from potatoes with sprouts will have identical genotypes as its "parent" and the potato grown from the seed may have a different genotype that its "parent" potato
B. The advantage of growing a potato form a sprout is that it will grow faster than if you started from a seed. The advantage of growing a potato form a seed is that you can plant it whenever you want.
One point answer
A. With the potato grown from seed, it will have the genes of both the plants that pollinated the flower. The potato grown from sprouts will contain the exact genes of the first potato.
B. The advantage of growing the potatoes form seed is that if the genes from one of the parents was defective, it may become a recessive gene and not effect this generation. The plant grown from sprouts will take less time to bloom and sprout because it doesn't need time to germinate.
|
|
|
|
|