SCIENCE 2 TEST
Directions
This booklet contains Science 2 (Earth Science and Biology) test. There are 25 questions in
Earth Science and 25 questions in Biology. This test measures skills and abilities highly
related to course works completed in Grades 1, 2, and 3 STEM schools.
The questions in the test are numbered, and the suggested answers for each question are
lettered (A, B, C, and D). On the answer document, the rows of ovals are numbered to match
the questions, and the ovals in each row are lettered to correspond to the suggested answers.
For each question, first decide which answer is best. Next, locate on the answer document the
row of ovals numbered the same as the question. Then, locate the oval in that row lettered the
same as your answer. Finally, fill in the oval completely. Use a soft lead pencil and make
your marks heavy and black (see below an example). DO NOT USE A PEN.
A
B C D
Mark only one answer to each question. If you change your mind about an answer, erase your
first mark thoroughly before marking your new answer. For each question, make certain that
you mark in the row of ovals with the same number as the question.
Only responses marked on your answer document will be scored. Your score on each test will
be based only on the number of questions you answer correctly during the time allowed for
that test. You will NOT be penalized for guessing. IT IS TO YOUR ADVANTAGE TO
ANSWER EVERY QUESTION EVEN IF YOU MUST GUESS.
If you finish a test before time is called for that test, you should use the time remaining to
reconsider questions you are uncertain about in that test.
Lay your pencil down immediately when time is called at the end of the test. You may NOT
for any reason fill in or alter ovals for the test after time is called for that test. To do so will
disqualify you from the examination. Do not fold or tear the pages of your test booklet.
DO NOT OPEN THIS BOOKLET UNTIL TOLD TO DO SO.
Page 1 (Biology)
Biology Test
25 Questions – 45 Minutes
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Passage I
Urease is an enzyme used by plants to break down urea (a nitrogen-containing compound)
into carbon dioxide and ammonia. Plants need nitrogen to grow and can obtain it from
ammonia, but not from urea. In soybean plants there are 2 different kinds of urease, one
produced in the seeds and the other produced in the leaves of the plant. Mutations in the
chromosomes of the soybean can stop production of either enzyme. In the following
experiments, 3 types of soybean plants were used: normal soybeans and 2 mutant strains, 1
lacking the seed urease (Strain 1) and 1 lacking the leaf urease (Strain 2).
Experiment 1
Separate areas in a field were planted with normal, Strain 1, and Strain 2 soybeans. All types
of soybeans appeared to grow, flower, and produce seeds equally well. There were no
externally detectable differences among the strains.
Experiment 2
Small pieces of plant tissue of equal weight were obtained from each type of soybean plant
and separately placed on media in culture dishes. Tissue growing in this way will become an
unorganized clump of cells referred to as callus. To provide a controlled nitrogen source, half
the tissue samples of each type were placed on media containing urea, and the other half of
the samples were placed on media containing ammonia. After 30 days, the weight gain for
each of the callus samples was determined. Results are shown in the table below.
Plant type
Normal
Strain 1
Strain 2
Weight gain (mg)
Urea
Ammonia
150
180
155
160
50
170
Question numbers 1 to 5 are related to this Passage I.
1. Which of the following not describes the role of urease in the plants grown in the field?
A. Urease activity in leaves is not essential for soybean growth.
B. Urease activity in seeds is not essential for soybean growth.
C. Urease breaks down into carbon dioxide and ammonia.
D. Urease is essential to the growth of soybeans.
Page 2 (Biology)
2. Which of the nitrogen sources in Experiment 2 served as the control group?
A. Urea, because it cannot be used by Strain 2.
B. Urea, because it can be broken down by urease.
C. Ammonia, because it will inhibit the effects of urease.
D. Ammonia, because all 3 strains of soybeans can use it.
3. Mutant strains are most useful in experiments like those in the passage because they:
A. Can be modified to suit almost any type of research.
B. Differ from normal strains in unknown, unpredictable ways.
C. Provide a natural, noninvasive way to vary a characteristic.
D. May produce unexpected results.
4. In studying the metabolic needs of the soybean strains, Experiment 2 was probably more
accurate than Experiment 1 because in Experiment 2 the:
A. Nitrogen source in the media were more controlled.
B. Nutrients in the soil could not be measured.
C. Nutrients in the soil were more controlled.
D. Callus was much different from the plants.
5. Suppose a third strain were found that was unable to produce either form of urease. If this
strain were subjected to the same procedures as those in the passage, what would be the
expected results?
A. Callus would not grow on urea or on ammonia; the plant would not grow in the field.
B. Callus would not grow on urea but would grow on ammonia; the plant would grow in
the field.
C. Callus would not grow on urea but would grow on ammonia; the plant would not
grow in the field.
D. Callus would grow on urea and on ammonia; the plant would grow in the field.
Page 3 (Biology)
Passage IV
In the 1940s, scientists thought all genetic material was contained in structures called
chromosomes and that chromosomes had been found only in the nucleus of a cell (not in the
cytoplasm):
Chromosomes are composed of 2 types of molecules, proteins and deoxyribonucleic acid
(DNA). Proteins are composed of subunits called amino acids. DNA consists of chains of
subunits called nucleotides. The parts of that responsible for the transmission of genetic
information are called genes.
Two scientists in the 1940s debate whether genes are made of proteins or DNA.
Protein Hypothesis
Genes are made only of proteins. Proteins make up 50% or more of a cell’s dry weight. Cells
contain 20 different amino acids that can be arranged in a virtually infinite number of ways to
make different proteins. The number and arrangement of different amino acids within a
protein form the codes that contain hereditary information. In contrast, only 4 different
nucleotides make up the DNA found in cells, and they are believed to form chains only in
certain ratios. As a result, the number of different combinations that DNA can carry is much
smaller than the number that proteins can carry.
DNA Hypothesis
Genes are made only of DNA. DNA is found exclusively in the cell’s nucleus, whereas
proteins are found throughout the nucleus and cytoplasm. Additionally, the amount of protein
in a cell varies from cell type to cell type, even within the same animal. Though DNA is less
abundant than proteins, the amount is consistent from cell type to cell type within the same
animal, except for the gametes (the reproductive cells). Gametes have half the amount of as
other cells in the body. Gametes also have half the typical number of chromosomes. Thus, the
amount of DNA in cell is correlated with the number of chromosomes in the cell. No such
correlation is found for proteins.
Question numbers 13 to 19 are related to this Passage IV.
13. Which of the following statements is most consistent with the DNA Hypothesis? The
amount of DNA will generally increase from cell type to cell type as the number of:
A. Amino acids in the nucleus increases from cell type to cell type.
B. Amino acids in the nucleus increases from cell type to cell type.
C. Chromosomes in the nucleus increases from cell type to cell type.
D. Chromosomes in the nucleus increases from cell type to cell type.
Page 4 (Biology)
14. By referring to the observation that DNA is found exclusively in the nucleus while
proteins are found throughout the cell, the scientist supporting the DNA Hypothesis implies
that genes are made only of DNA because which of the following are also found only in the
nucleus?
A. Chromosomes
B. Gametes
C. Vitamins
D. Fatty acids
15. According to the passage, a difference between DNA and proteins is that both types of
molecules:
A. Proteins are found only in gametes while DNA is not.
B. Proteins and DNA are abundant in the cytoplasm.
C. Proteins contain 20 different amino acids while DNA contain 4 types of nucleotides.
D. Protein contain nitrogen base while DNA contain peptides.
16. According to the Protein Hypothesis, which of the following observations provides the
strongest evidence that genes are composed of proteins?
A. Proteins composed of 20 amino acids.
B. Protein is composed of smaller subunits than are DNA.
C. Proteins are abundant in the nucleus only.
D. The concentration of proteins is generally consistent from cell to cell.
17. Mitochondria are organelles located in the cytoplasm that are responsible for energy
transformation in a cell. After the 1940s, it was observed that mitochondria contain their own
genes. This observation contradicts evidence stated in which hypothesis?
A. The Protein Hypothesis, because if genes are made of proteins, the observation would
show that proteins are present inside the nucleus.
B. The DNA Hypothesis, because if genes are made of DNA, the observation would
show that DNA is present outside the nucleus.
C. The DNA Hypothesis, because if genes are made of DNA, the observation would
show that DNA is present inside the nucleus.
D. The Protein Hypothesis, because if genes are made of proteins, the observation would
show that proteins are present outside the nucleus.
Page 5 (Biology)
18. The scientist who describes the DNA Hypothesis implies that the Protein Hypothesis is
weakened by which of the following observations?
A. Proteins are found only in the nucleus.
B. Protein molecules are composed of many subunits.
C. For a man, the amount of protein in different types of cells is not the same.
D. For a man, the amount of protein in the gametes is half that found in other types of
cells.
19. Which of the following illustrations of a portion of a protein molecule is consistent with
the description in the passage?
A.
B.
C.
D.
END OF SCIENCE 2 TEST
STOP!
Page 6 (Biology)