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Genetics and DNA vocabulary words

Written for biology students studying heredity and molecular genetics, this list collects the terms most often used to explain how traits pass from parents to offspring and how DNA carries that information. Review it before a unit test or use it to make sense of textbook diagrams on replication and inheritance.

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Genetics and DNA vocabulary words

Word	Meaning	In a sentence
genenoun	A unit of hereditary material, made of DNA, that determines a particular trait in an organism.	A single gene can determine whether a pea plant produces smooth or wrinkled seeds.
DNAabbreviation	The molecule inside cells that carries the genetic instructions used to build and maintain living organisms.	Scientists compared DNA samples to confirm the identity of the remains.
RNAabbreviation	Ribonucleic acid, a molecule in cells that helps carry genetic instructions and build proteins.	Messenger RNA carries genetic instructions from DNA to the cell's protein-making machinery.
chromosomenoun	A thread-like structure of tightly coiled DNA that carries genes and passes hereditary information to offspring.	Humans typically have forty-six chromosomes arranged in twenty-three pairs within each cell.
allelenoun	One of two or more alternative forms of a gene that occupy the same position on a chromosome.	A child may inherit one allele for eye color from each parent.
genotypenoun	The specific genetic makeup of an individual organism, as distinct from its observable traits.	Two plants can have the same genotype but look different because of their environment.
phenotypenoun	The observable physical or biochemical characteristics of an organism, resulting from its genes and environment.	Eye color is one visible phenotype determined by a combination of several genes.
hereditynoun	The passing of physical or mental traits from parents to their offspring through genes.	Heredity explains why the twins share the same curly hair and dimples.
traitnoun	A distinguishing quality or characteristic belonging to a person, animal, or thing.	Patience is a trait that makes her an excellent teacher.
mutationnoun	A permanent change in an organism's genetic material that can be passed on to offspring.	A random mutation gave the beetle population a slightly darker shell color.
dominantadjective	Having the most power, control, or influence over others in a group, situation, or system.	The dominant wolf in the pack ate first and decided where the group traveled.
recessiveadjective	In genetics, describing a gene or trait that is expressed only when no dominant version of the gene is present.	Blue eyes are a recessive trait, so both parents must carry the gene for a child to have them.
genomenoun	The complete set of genetic material present in an organism.	Scientists mapped the entire human genome to identify genes linked to disease.
nucleotidenoun	A basic building block of DNA and RNA, made of a sugar, a phosphate group, and a nitrogen base.	Each nucleotide pairs with a specific partner to form the double helix of DNA.
replicationnoun	The process of copying or reproducing something exactly, especially in science or research.	Scientists rely on replication of experiments to confirm that results are reliable.
transcriptionnoun	A written or typed version of spoken words, produced by listening to and recording what was said.	The court reporter produced a full transcription of the witness's testimony within a day.
translationnoun	A piece of writing or speech that has been converted from one language into another.	The publisher commissioned a new translation of the ancient Greek epic.
proteinnoun	A nutrient made of amino acids that builds and repairs body tissue and supports muscle growth.	Eggs, chicken, and beans are all good sources of protein for a balanced diet.
gametenoun	A mature reproductive cell, such as a sperm or egg, that unites with another to form a new organism.	In humans, the male gamete is the sperm and the female gamete is the egg.
zygotenoun	The single cell formed when a sperm cell and an egg cell fuse during fertilization.	Within hours of fertilization, the zygote begins dividing rapidly to form an embryo.
pedigreenoun	The recorded ancestry of a person or animal, especially one showing distinguished or purebred lineage.	The show dog's pedigree traced back five generations of championship winners.
inheritancenoun	Money, property, or a title received from someone after their death, or a trait passed down biologically.	She used her small inheritance from her grandmother to pay off her student loans.
genetic codenoun	The set of rules by which information in DNA is translated into proteins.	Scientists cracked the genetic code to understand how DNA sequences produce specific proteins.
base pairnoun	Two complementary nucleotide bases, such as adenine and thymine, joined together in a DNA or RNA molecule.	A single mutation changed one base pair in the gene, altering the protein it produced.
chromatidnoun	One of the two identical strands formed when a chromosome duplicates before cell division.	Each replicated chromosome consists of two sister chromatids joined at the centromere.
offspringnoun	The young or children produced by a person, animal, or plant.	The lioness fiercely protected her offspring from the approaching hyenas.
hybridnoun	The offspring produced by crossing two different species, varieties, or breeds.	The mule is a hybrid produced by crossing a female horse with a male donkey.
carriernoun	A person, company, or vehicle that transports goods, passengers, or information from place to place.	The airline is one of the largest carriers operating international flights.

How DNA replication works

DNA replication is the process by which a cell copies its DNA before dividing, so each new cell gets a complete set of instructions. Nucleotides pair up to form the double helix, and replication relies on that base-pairing to build an accurate copy. Understanding replication also helps explain transcription and translation, the steps that turn DNA instructions into proteins.

Dominant and recessive traits

A dominant allele shows its effect even when only one copy is present, while a recessive allele only shows up when two copies are inherited. Genotype refers to the genetic makeup an organism carries, while phenotype is the trait you can actually observe, like eye color. These words help describe why a trait might skip a generation.

Frequently asked questions

What is the difference between genotype and phenotype?

Genotype is the genetic information an organism carries, while phenotype is the observable trait that genotype produces.

What is heredity?

Heredity is the passing of traits from parents to offspring through genes.