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Which of the following is an example of a chemical change?

A. Releasing compressed gas to make a bottle-rocket launch

B. Adding water to clay to make slip

C. Crystalizing honey to make candy

D. Including baking soda in a recipe to make it less sour

Answer Explanation:

A chemical change involves a chemical reaction and new substances are produced. When baking soda is added to something sour (acidic) it neutralizes the acid and forms new molecules, in this case carbon dioxide and water. A physical change does not produce new substances. Phase changes such as evaporation and sublimation are physical changes. Changing the ratio of ingredients in a mixture, like adding more water to clay, does not change it chemically, but it can change some of the mixture's physical properties.

Therefore, the Correct Answer is D.

Q #1: Your class is competing with another class to determine who has the best plant color. Your class decides to test a couple of solutions to determine which would be best for overall plant color before competing. Starting with four sets of four plants, the class decides to water each set with a different solution. They water them once a week with 200ml of the following solutions: water, diet soda, 1% bleach solution, and a 1% salt solution. All plants are placed in the window that receives the recommended amount of light. After a month of testing, your class notices that only two plants are alive, but one of those two does not look healthy. Based on these results, which of the following would be a good hypothesis to design the next experiment around?

A. Plants need more than 200 mL of liquid per week.

B. Salt has no impact on plant health.

C. Salt contains useful nutrients for plants.

D. A combination of the solutions tested will produce healthier plants.

Answer Explanation

Since only 2 out of the initial 16 plants survived the whole month, it would be reasonable to test variables that were shared by all the plants. As such, the amount of liquid the plants need would be a good follow-up experiment. It is not specified as to which plants survived, so there is not enough information to think that testing the impact of salt is warranted. Additionally, since almost all the plants died, it is not reasonable to assume that a combination of the solutions would have an impact.
Q #2: Enzymes catalyze biochemical reactions by ________

A. Lowering the potential energy of the products

B. Separating inhibitors from products

C. Forming a complex with the products

D. Lowering the activation energy of the reaction

Answer Explanation

Enzymes act as catalysts for biochemical reactions. A catalyst is not consumed in a reaction, but rather lowers the activation energy for that reaction. The potential energy of the substrate and the product remain the same, but the activation energy-the energy needed to make the reaction progress can be lowered with the help of an enzyme.
Q #3: There are three Insects that are being compared under a microscope. As a scientist, you decide that measuring them would be an important part of recording their data. Which unit of measurement would best for this situation?

A. Centimeters

B. Meters

C. Micrometers

D. Kilometers

Answer Explanation

The best use of the International System of Units (SI) for this situation would be the use of the micrometer as it is the smallest unit of measurement provided and the scientist is using a microscope to view the insects.
Q #4: A group of researchers have conducted a study examining the impact of a new medication on blood pressure. What is the purpose of submitting the study for publication in a peer-reviewed journal?

A. Other scientists can validate or disprove the findings.

B. Publication in a peer-reviewed journal will guarantee acceptance of the study's conclusions.

C. Publication in a peer-reviewed journal is unnecessary for this type of study.

D. Publication in a peer-reviewed journal will lead to the manipulation of the study's results.

Answer Explanation

Other scientists can validate or disprove the findings.

The purpose of submitting a study for publication in a peer-reviewed journal is to have the study’s methodology, results, and conclusions evaluated by other experts in the field.

This process helps to ensure the quality and validity of the research. Choice B.

Publication in a peer-reviewed journal will guarantee acceptance of the study’s conclusions is incorrect because publication in a peer-reviewed journal does not guarantee acceptance of the study’s conclusions.

The study’s findings may still be subject to debate and further research. Choice C.

Publication in a peer-reviewed journal is unnecessary for this type of study is incorrect because publication in a peer-reviewed journal is an important step in the scientific process for all types of studies.

Choice D.

Publication in a peer-reviewed journal will lead to the manipulation of the study’s results is incorrect because the peer-review process is designed to prevent manipulation of results by ensuring that the study meets rigorous standards for quality and validity.
Q #5: What is the role of ribosomes?

A. Make proteins

B. Waste removal

C. Transport

D. Storage

Answer Explanation

A ribosome is a structure of eukaryotic cells that makes proteins.
Q #6: Which of the following are formed when the plasma membrane surrounds a particle outside of the cell?

A. Golgi bodies

B. Rough endoplasmic reticulum

C. Secretory vesicles

D. Endocytic vesicles

Answer Explanation

Endocytosis is a process by which cells absorb larger molecules or even tiny organisms, such as bacteria, that would not be able to pass through the plasma membrane. Endocytic vesicles containing molecules from the extracellular environment often undergo further processing once they enter the cell.
Q #7: Which of these body parts does NOT produce melanin?

A. Hair

B. Nails

C. Skin

D. Iris

Answer Explanation

While melanin can be found in nails, it is not produced there. Melanin is the pigment that provides color to skin, hair, and eyes. Although the specific coloring of one's skin, hair, and eyes are genetically determined. environmental factors such as sun exposure can increase melanin production in the skin to help protect it from damage.
Q #8: Where is the scapula in relation to the olecranon?

A. Distal

B. Lateral

C. Ventral

D. Superior

Answer Explanation

The scapula, commonly known as the shoulder blade, is above the olecranon, commonly known as the elbow. Conversely, the olecranon is distal or inferior to the scapula.
Q #9: Which of the following is NOT true concerning correlation?

A. Correlation can show the relationship between variables.

B. Correlation can show cause and effect.

C. Correlation can show linear relationships.

D. Correlation can show nonlinear relationships.

Answer Explanation

Correlations may be positive or negative and linear or nonlinear. However, correlation does not determine cause and effect. Correlation does not necessarily mean causation.
Q #10: Which of the following statements concerning the states of matter is NOT true?

A. Plasmas are high-temperature collections of ions and free electrons.

B. Solids are the least compressible due to the more rigid positions of the particles.

C. Gases have no definite volume and expand to fill their containers

D. Liquids have no definite shape and no definite volume.

Answer Explanation

Liquids have no definite shape, but they do have a definite volume. While the particles of liquids move more freely than those in solids, they do maintain a definite volume.

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