Identifying the Substance of Genes

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Gene Noun

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[jeen]

Back

Gene

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A segment of DNA that is a chemical factor determining traits passed from one generation to the next.

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Example: This image shows that a gene is a specific section of a DNA molecule, which is tightly coiled into a chromosome found inside a cell's nucleus.

Front

Transformation Noun

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[trans-for-mey-shuhn]

Back

Transformation

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The process where one strain of bacteria is genetically changed by incorporating a gene or genes from another strain.

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Example: This diagram shows a bacterium taking in a new piece of DNA, called a plasmid. This process of absorbing foreign genetic material is called transformation.

Front

Enzyme Noun

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[en-zahym]

Back

Enzyme

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A type of protein that acts as a catalyst to speed up specific biochemical reactions, such as breaking down molecules.

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Example: An enzyme has an active site that fits a specific substrate. It changes the substrate into products and then releases them, remaining unchanged to repeat the process.

Front

DNA (Deoxyribonucleic acid) Noun

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[dee-ok-see-rahy-boh-noo-klee-ik as-id]

Back

DNA (Deoxyribonucleic acid)

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The nucleic acid molecule that stores and transmits the genetic information from one generation of an organism to the next.

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Example: This diagram shows DNA's double helix structure, with a sugar-phosphate backbone and rungs made of paired nitrogenous bases: A with T, and G with C.

Front

Virus Noun

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[vahy-ruhs]

Back

Virus

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A tiny, nonliving infectious particle that replicates inside the living cells of other organisms by injecting its genetic material.

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Example: This diagram shows the parts of a virus, including the viral genome, which is the genetic material (genes) that allows the virus to replicate.

Front

Bacteriophage Noun

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[bak-teer-ee-oh-feyj]

Back

Bacteriophage

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A specialized type of virus that specifically infects, replicates within, and often destroys bacterial cells.

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Example: This diagram shows a bacteriophage, a virus that infects bacteria, with its DNA genetic material stored inside a protein head (capsid).

Front

Radioactive Isotope Noun

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[rey-dee-oh-ak-tiv ahy-suh-tohp]

Back

Radioactive Isotope

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An unstable form of a chemical element that releases radiation and can be used as a marker to track molecules.

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Example: This diagram shows isotopes of hydrogen, which have the same number of protons but different numbers of neutrons, changing their mass number.

Front

Heredity Noun

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[huh-red-i-tee]

Back

Heredity

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The biological process responsible for passing genetic information and traits from one generation of an organism to the next.

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Example: This pedigree chart shows how genetic traits are passed from parents to their children over generations, which is the definition of heredity.

Front

Gene Expression Noun

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[jeen ik-spresh-uhn]

Back

Gene Expression

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The process by which the genetic information stored in DNA is used to synthesize a functional gene product, like a protein.

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Example: This diagram shows how a gene's instructions in DNA are first copied into mRNA (transcription) and then used to build a protein (translation).

Front

Nucleic Acid Noun

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[noo-klee-ik as-id]

Back

Nucleic Acid

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A class of essential macromolecules, including DNA and RNA, that carry and transmit genetic information in all living cells.

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Example: This diagram shows the double helix structure of DNA, a type of nucleic acid, identifying its sugar-phosphate backbone and the four nitrogenous bases (A, T, C, G).