1.
Which statement best describes the relationship that exists among proteins, DNA, and cells?
Correct Answer
D. Cells contain DNA, which controls the production of proteins.
Explanation
Cells contain DNA, which controls the production of proteins. This statement accurately describes the relationship among proteins, DNA, and cells. DNA serves as the genetic material in cells and contains the instructions for making proteins. Proteins are the building blocks of cells and perform various functions within the cell. The DNA in cells controls the production of proteins by providing the necessary genetic information. Therefore, the statement correctly explains the relationship between proteins, DNA, and cells.
2.
Which type of molecule do whales use for energy storage and insulation?
Correct Answer
B. Fat
Explanation
Whales use fat molecules for energy storage and insulation. Fat is an efficient form of energy storage because it contains more than twice the amount of energy per gram compared to carbohydrates like glucose or starch. Additionally, the high concentration of fat in whale blubber provides insulation, helping them to maintain their body temperature in cold water.
3.
Some microorganisms, such as yeast, produce energy in an oxygen-free environments through the process of ___.
Correct Answer
C. Anaerobic respiration
Explanation
Anaerobic respiration is the process through which microorganisms, such as yeast, produce energy in the absence of oxygen. This process involves the breakdown of glucose into simpler compounds, such as ethanol or lactic acid, and releases a small amount of energy. Unlike aerobic respiration, which occurs in the presence of oxygen and produces a larger amount of energy, anaerobic respiration is a less efficient process.
4.
Which statement correctly identifies the cells?
Correct Answer
A. Cell 1 is prokaryotic; cell 2 is eukaryotic.
Explanation
Cell 1 is identified as prokaryotic because prokaryotic cells are characterized by the absence of a nucleus and other membrane-bound organelles. Cell 2 is identified as eukaryotic because eukaryotic cells have a nucleus and other membrane-bound organelles. This answer correctly identifies the characteristics of both cell types.
5.
Antibodies are composed primarily of amino acids. In which class of biomolecules would antibodies belong?
Correct Answer
A. Proteins
Explanation
Antibodies are composed primarily of amino acids, which are the building blocks of proteins. Proteins are a class of biomolecules that play a crucial role in various biological processes, including immune responses. Antibodies are specific proteins produced by the immune system to target and neutralize foreign substances, such as bacteria or viruses. Therefore, antibodies belong to the class of biomolecules known as proteins.
6.
Proteins are synthesized in which organelle?
Correct Answer
A. 3
Explanation
Proteins are synthesized in the ribosomes, which are located in the cytoplasm of the cell. The ribosomes are responsible for reading the genetic information stored in DNA and using it to assemble amino acids into proteins. Therefore, option 3 is the correct answer as it represents the ribosomes, the organelle where protein synthesis occurs.
7.
In a typical animal cell, which component contains the greatest amount of water?
Correct Answer
A. Cytoplasm
Explanation
The cytoplasm contains the greatest amount of water in a typical animal cell. Cytoplasm is a gel-like substance that fills the cell and contains various organelles, such as ribosomes and the nucleus. It is composed mostly of water, along with proteins, salts, and other molecules. The high water content of the cytoplasm helps to maintain the cell's shape and allows for the movement of molecules within the cell.
8.
The diagram shows a section of a cell membrane that includes a channel protein. The function of this protein is to __.
Correct Answer
A. Allow certain substances to enter or leave the cell
Explanation
The channel protein in the cell membrane is responsible for allowing certain substances to enter or leave the cell. This protein acts as a gate, selectively allowing specific molecules to pass through the cell membrane while blocking others. By regulating the movement of substances, the channel protein helps maintain the cell's internal environment and allows the cell to communicate with its surroundings.
9.
This diagram shows a plant cell. Which structure is found in a plant cell but is absent in an animal cell?
Correct Answer
A. 4
Explanation
The correct answer is 4 because it is the only option that indicates a structure that is found in a plant cell but is absent in an animal cell.
10.
A freshwater plant is placed in a container of saltwater. What will most likely happen to the cells of the plant?
Correct Answer
C. They will shrink because water will move out of them.
Explanation
When a freshwater plant is placed in a container of saltwater, the concentration of salt outside the plant cells is higher than inside the cells. This creates a hypertonic environment, causing water to move out of the plant cells through osmosis. As a result, the cells will lose water and shrink, leading to their shrinkage.