High School Biology : Introductory Topics

Study concepts, example questions & explanations for High School Biology

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Example Questions

Example Question #2 : Understanding Requirements For Life And Cell Theory

What determines the primary structure of a protein?

Possible Answers:

The folding of the R groups in the side chains of amino acids

The array of polypeptide chains lying side by side

The sequence of amino acids in a chain

The segments in the polypeptide chain that forms coils

Correct answer:

The sequence of amino acids in a chain

Explanation:

The sequence of amino acids is called a protein's primary structure. Each protein has a unique sequence of amino acids. A difference of just one amino acid in a chain of hundreds can be deadly to the organism. For example, mutation leading to a single amino acid change is responsible for sickle cell anemia.

Example Question #991 : High School Biology

What makes up the tertiary structure of a protein?

Possible Answers:

The folding caused by interactions between R groups of various amino acids in the same polypeptide chain

Disulfide bonds between two valine amino acids

Covalent bonds that occur between R groups with a positive charge and R groups with a negative charge

Carbon bonds between R groups with a positive charge and R groups with a negative charge

Correct answer:

The folding caused by interactions between R groups of various amino acids in the same polypeptide chain

Explanation:

The tertiary structure of a protein is created by various interactions between the R groups in the chain. This makes the protein fold three-dimensionally.

One example would be ionic bonds forming between a positively charged R group and a negatively charged R group. Covalent disulfide bonds will create a tertiary shape between two cysteine amino acids. Hydrophobic R groups will also contribute to the structure, bending toward one another to avoid contact with the aqueous environment.

Example Question #11 : Understanding Requirements For Life And Cell Theory

What forms the quaternary structure of a protein?

Possible Answers:

Coiled proteins attach to each other to form a sheet of protein

Subunits of the protein fit together to make a larger protein complex

The nonpolar attraction between proteins cause them to fit together to make a larger protein complex

A regular pattern of hydrogen bonds between amino acids of different chains

Correct answer:

Subunits of the protein fit together to make a larger protein complex

Explanation:

A quaternary protein structure is made up of two or more polypeptide chains that fit together based on their shape and polarities, like a jigsaw puzzle. The subunits also fit together by forces of attraction between positively charged regions and negatively charged regions. Not all proteins have quaternary structure.

Example Question #12 : Understanding Requirements For Life And Cell Theory

How do amino acids enter the bloodstream from the small intestine?

Possible Answers:

Active transport

Diffusion

Facilitated diffusion

Osmosis

Correct answer:

Active transport

Explanation:

Active transport is used to carry amino acids from the lumen of the small intestine into the blood stream. Active transport requires the use of energy (ATP) in order to transport molecules. In this case, amino acids are large, blulky, and frequently polar. All of these characteristics make them hard to transport across a plasma membrane.

Example Question #13 : Understanding Requirements For Life And Cell Theory

Which of the following is not a type of protein molecule?

Possible Answers:

Keratin

Enzymes

Hormones

Steroids

Correct answer:

Steroids

Explanation:

Steroids are derived from cholesterol, which is a lipid.

Many hormones are are classified as peptide hormones, and are made of protein. Keratin is a hard structural protein found in hair and nails. Enzymes are catalytic proteins that facilitate biochemical reactions in the body.

Example Question #13 : Understanding Requirements For Life And Cell Theory

What happens to the quaternary of a protein when it is heated above 60 degrees Celsius?

Possible Answers:

Condensation occurs

Hydrolyzation occurs

Denaturation occurs

Catalyzation occurs

Correct answer:

Denaturation occurs

Explanation:

When a protein is exposed to extreme conditions, such as high temperature or acidity, the interactions that provide protein structure are disrupted. The result is denaturation, or the loss of structure.

When conditions are returned to optimal levels, the protein can often return to its normal structure and remain functional. Denaturation affects the interactions that give the protein shape, but does not affect the peptide bonds that hold amino acids together.

Example Question #14 : Understanding Requirements For Life And Cell Theory

Which of the following is not a tenet of cell theory?

Possible Answers:

All living organisms are composed of cells

All cells have nuclei which contains the genetic material

Cells are the most basic unit of life

All cells come from preexisting cells

Correct answer:

All cells have nuclei which contains the genetic material

Explanation:

The cell theory has three basic parts: all living things are made of cells, the cell is the smallest unit of life, and all cells come from preexisting cells. Prokaryotic cells are indeed cells and they do not contradict any tenets of the cell theory. However, they do not contain nuclei; rather, their genetic material is contained in the cytoplasm.

Example Question #15 : Understanding Requirements For Life And Cell Theory

Solution A has a pH of 1.  Solution B has a pH of 8.  Relatively speaking, how acidic/basic is solution A?

Possible Answers:

Very basic

Very acidic

Acidic

Neutral

Basic

Correct answer:

Very acidic

Explanation:

The pH of a solution is defined as the the concentration of H+ ions in the solution.  The pH of a solution declines  as H+ concentration increases.  On the pH scale, ranging from 0 to 14, 7 is neutral.  Substances below 7 are more acidic, 0 being the most acidic.  Substances above 7 are more basic, 14 being the most basic. 

Example Question #16 : Understanding Requirements For Life And Cell Theory

Which of the following is not a characteristic of a living organism?

Possible Answers:

Composed of plutonium

Contains DNA

Uses energy

Reproduces

Correct answer:

Composed of plutonium

Explanation:

“Composed of plutonium” is not a characteristic of a living organism. The other three choices are characteristics of living organisms. Organisms use energy in their metabolic processes. Organisms reproduce either asexually or sexually to make offspring for the next generation. Organisms from the simplest prokaryote to the human species contain DNA—the universal genetic code.

Example Question #41 : Attributes Of Life

Which of the following choices forms organs?

Possible Answers:

Cells

Tissues

Organisms

Atoms

Correct answer:

Tissues

Explanation:

The correct order of the level of organization of an individual is as follows: cells, tissue, organs, organ systems, and organism. In other words, tissues form organs. For example, in a human being the order in the musculatory system would be: muscle cell, muscle tissue, bicep muscle, musculatory system, and human being.

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