FREE Biology End-of-Course Questions and Answers
Assume a group of scientists has managed to set up an experiment simulating the conditions of early Earth that resulted in a cell with DNA using RNA to produce proteins from amino acids as modern cells do. What conclusion could they draw from this experiment?
Explanation:
The successful simulation of conditions leading to the formation of a cell with DNA using RNA to produce proteins suggests that it is possible for a cell similar to a modern cell to form under the conditions of the experiment. This conclusion implies that the experiment provided valuable insights into the origins of early life on Earth and the potential pathways for the development of cellular structures and functions.
Some proteins catalyze biochemical reactions. If a genetic defect prevented a protein catalyst from being produced, which of the following do you predict would happen in the cell?
Explanation:
Option B is the most likely outcome if a genetic defect prevents a protein catalyst from being produced. Proteins that act as catalysts (enzymes) facilitate biochemical reactions by lowering the activation energy required for the reaction to occur. Without the enzyme, the reaction would proceed much slower or may not occur at all, as the activation energy barrier would be too high for the reaction to proceed efficiently.
Water has a much higher specific heat than most other covalent compounds. What do you predict might happen if water had a low specific heat instead?
Explanation:
Water's high specific heat capacity helps to stabilize temperatures in aquatic environments and regulate the climate on Earth. If water had a low specific heat instead, it would heat up or cool down much more quickly with changes in energy input. This rapid temperature fluctuation could be detrimental to organisms, particularly those sensitive to temperature changes, potentially leading to their death.
In which of the following circumstances would it be most likely for large organic molecules to form during a laboratory experiment?
Explanation:
RNA molecules, particularly ribozymes, can act as catalysts, facilitating chemical reactions necessary for the formation of large organic molecules. If RNA segments capable of catalyzing such reactions formed during a laboratory experiment, they could promote the synthesis of large organic molecules by facilitating the assembly of smaller molecules into larger ones.
To help patients replenish bodily fluids quickly during an illness, doctors need to understand how cells behave in their environment. Doctors have confidence in what they know about how cells behave because
Explanation:
Cell theory, which states that all living organisms are composed of cells, cells are the basic units of structure and function in living organisms, and all cells come from pre-existing cells, has undergone rigorous testing and refinement over centuries. Its principles have been consistently observed and validated through scientific experimentation and observation, leading to confidence in its accuracy among medical professionals.
Based on your knowledge of scientific investigations, which stage of scientific investigation did the invention of the microscope significantly advance?
Explanation:
The invention of the microscope revolutionized the gathering of data for scientific investigations by allowing scientists to observe and study microscopic structures and organisms that were previously invisible to the naked eye. This advancement greatly expanded the scope of scientific inquiry and enabled researchers to gather detailed data about biological, cellular, and molecular phenomena.
Which of the following best describes a result of the polar nature of water molecules?
Explanation:
The polar nature of water molecules allows them to form hydrogen bonds with other polar or charged substances, such as ions. This property enables water to dissolve many ionic compounds, making it an effective solvent for a wide range of substances.
If a company claims that its product has been proven scientifically, which of the following should have taken place if the results are to be considered reliable?
Explanation:
For scientific results to be considered reliable, they should undergo peer review, where other experts in the field critically evaluate the research methodology and findings. Additionally, for validity, the results should be replicable, meaning that other researchers should be able to conduct the same experiment and achieve similar results independently.
Which of the following best describes the difference between the functions of nucleic acids and enzymes?
Explanation:
Option B accurately describes the main differences between nucleic acids and enzymes. Nucleic acids, such as DNA and RNA, carry the genetic information needed for protein synthesis. Enzymes, on the other hand, are proteins that act as biological catalysts, speeding up chemical reactions in living organisms. This explanation succinctly captures the distinct functions of nucleic acids and enzymes in cellular processes.
Which of the following best summarizes why the technological invention of microscopes was important to biology?
Explanation:
The invention of microscopes enabled scientists to observe and study cells, leading to the development of the cell theory, which states that all living organisms are composed of cells, cells are the basic units of structure and function in living organisms, and all cells come from pre-existing cells. This theory revolutionized our understanding of biology and laid the foundation for modern cell biology.
Which of the following best compares the structures of lipids and carbohydrates?
Explanation:
Option B provides an accurate comparison between lipids and carbohydrates. Both lipids and carbohydrates are composed of carbon, hydrogen, and oxygen atoms. However, carbohydrates have repeating structural units (monosaccharides) that form polysaccharides, while lipids do not have such repeating units. This succinctly highlights a key difference in their structural organization.