Scientific Investigation
A scientist thinks that people who exercise for an hour every day may have lower cholesterol levels than people who don't exercise.
What is this statement?
A. A law
B. A hypothesis
C. An observation
D. A conclusion
Hypothesis
Which of the following is a chemical reaction?
A. Breaking a glass pane
B. Freezing water
C. Digestion of food
D. Cutting down a tree
Digestion of food
Who first used the term "cell" after observing structures in cork?
A. Robert Brown
B. Robert Hooke
C. Anton van Leeuwenhoek
D. Rudolf Virchow
Robert Hooke
Essential amino acids cannot be produced by the human body.
Which biomolecule provides essential amino acids in our diet?
A. Proteins
B. Fats
C. Carbohydrates
D. Disaccharides
Proteins
A white blood cell surrounds a bacterium and pinches off a vacuole containing the bacterium.
What process is occurring?
A. Exocytosis
B. Diffusion
C. Endocytosis
D. Osmosis
Endocytosis
A scientist measures cholesterol levels in people who exercise and people who do not exercise.
What type of variable is cholesterol level?
A. Independent variable
B. Controlled variable
C. Dependent variable
D. Qualitative variable
Dependent variable
Which equation correctly represents the balanced reaction between iron and oxygen?
A. 4Fe + 3O₂ → 2Fe₂O₃
B. 3Fe + 4O₂ → 2Fe₂O₃
C. 2Fe + 4O₂ → 3Fe₂O₃
D. 3Fe + 3O₂ → 4Fe₂O₃
4Fe + 3O₂ → 2Fe₂O₃
Who was the first person to observe living cells in a drop of pond water?
A. Robert Hooke
B. Zacharias Janssen
C. Anton van Leeuwenhoek
D. Theodor Schwann
Anton van Leeuwenhoek
Which is a major difference between DNA and RNA?
A. DNA is usually single stranded while RNA is usually double stranded.
B. RNA contains uracil while DNA contains thymine.
C. DNA contains uracil while RNA contains thymine.
D. RNA does not contain cytosine.
RNA contains uracil while DNA contains thymine.
Different types of white blood cells recognize different foreign particles because their receptors are:
A. The same for all cells
B. Specific for particular cells
C. Never found on cells
D. Identical to DNA
Specific for particular cells
Jon wants to study how the amount of folic acid affects DNA formation in microbes.
Which correctly identifies the variables?
A. Folic acid = dependent; DNA synthesized = independent
B. Folic acid = independent; DNA synthesized = dependent
C. Both are independent
D. Both are dependent
Folic acid is independent; DNA synthesized is dependent
Which compound is inorganic?
A. C₆H₁₂O₆
B. KH₂PO₄
C. CH₃COOH
D. C₂H₆
KH₂PO₄
A model of a plant cell, animal cell, and bacterial cell must include which structure besides the cytoplasm and cell membrane?
A. Nucleus
B. Golgi apparatus
C. Chloroplast
D. Ribosome
Ribosome
A scientist discovers genetic material containing RNA but no DNA.
What is the specimen most likely to be?
A. Plant
B. Fungus
C. Bacterium
D. Virus
Virus
Which tissue supports the framework of the liver, while epithelial tissue helps protect and line surfaces?
A. Connective tissue and epithelial tissue
B. Nervous tissue and muscle tissue
C. Muscle tissue and connective tissue
D. Epithelial tissue and nervous tissue
Connective tissue and epithelial tissue
Which four are unavoidable limitations when conducting medical research with human subjects?
A. Trials may be difficult or impossible to repeat on the same subjects.
B. Subjects may report an inaccurate medical history.
C. It can be difficult to control all possible variables.
D. It is impossible to develop testable questions about humans.
E. Ethical and privacy concerns must be considered.
Answer: A, B, C, E
Match each formula with its correct description:
Descriptions:
A. Element
B. Organic compound
C. Inorganic elemental molecule
D. Inorganic compound
Which organelle is primarily responsible for producing usable energy from food in cells?
A. Chloroplast
B. Mitochondrion
C. Nucleus
D. Ribosome
Mitochondrion
Why can a thyroid hormone affect heart cells but not necessarily every cell in the body?
A. Heart cells have specific receptors for the hormone.
B. Heart cells contain different genetic material.
C. All cells produce the same hormones.
D. Only heart cells contain DNA.
Heart cells have specific receptors for the hormone.
Place the steps for producing the protein pepsinogen in the correct order.
Answer:
1 → 2 → 3 → 4 → 5
A colorimeter consistently gives a reading that is five points lower than the actual value. A second colorimeter gives the correct reading consistently.
Which statements are correct?
A. The first colorimeter is reliable but not valid.
B. The second colorimeter is valid and reliable.
C. Both colorimeters are reliable and valid.
D. The first colorimeter should be used without repeating the experiment.
Answer: A and B
A student observes that two clear liquids are mixed together. The mixture becomes cloudy and a solid forms.
What is the best evidence that a chemical reaction occurred?
A. The liquids were both clear.
B. The temperature stayed the same.
C. A new substance formed.
D. The liquids were mixed together.
A new substance formed.
Which statement best describes the difference between mitochondria and chloroplasts?
A. Mitochondria make food while chloroplasts digest food.
B. Mitochondria produce energy from food, while chloroplasts use sunlight to make food.
C. Both organelles perform photosynthesis.
D. Chloroplasts are found in animal cells while mitochondria are found only in plants.
Mitochondria produce energy from food, while chloroplasts use sunlight to make food.
Which statement best explains how DNA and RNA differ?
A. DNA contains uracil and RNA contains thymine.
B. DNA is usually double stranded and contains thymine, while RNA is usually single stranded and contains uracil.
C. DNA and RNA contain exactly the same bases.
D. RNA contains no genetic information.
DNA is usually double stranded and contains thymine, while RNA is usually single stranded and contains uracil.
Sienna wants to determine whether plants grow toward light. She develops a hypothesis, places one plant near a window and another in a dark room with a small opening, and records the direction of growth over six weeks.
Which sequence correctly represents the scientific process?
A. Hypothesis → Experiment → Observation/Data Collection → Conclusion
B. Experiment → Hypothesis → Conclusion → Observation
C. Observation → Conclusion → Hypothesis → Experiment
D. Conclusion → Experiment → Hypothesis → Observation
Hypothesis → Experiment → Observation/Data Collection → Conclusion