Genetics and Cell Division Vocabulary Terms

Essential Genetics and Cell Biology Vocabulary

• Alleles: Different forms of a gene.
• Cell Cycle: The series of events that take place in a cell leading to its division and duplication (replication) that produces two daughter cells.
• Chromosome: A structure of DNA, protein, and RNA found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements, and other nucleotide sequences.
• Codominance: A phenomenon in which a single gene has more than one dominant allele.
• Cytokinesis: The process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells.
• Dominant Allele: A genetic trait that always shows or is expressed.
• Fertilization: The fusion of gametes to initiate the development of a new individual organism.
• Gamete: A reproductive cell or sex cell that contains the haploid set of chromosomes, e.g., a spermatozoon or sperm cell (male reproductive cell) and an egg cell or ovum (female reproductive cell).
• Gene: A segment of DNA (on a specific site on a specific chromosome) that controls the physical and inheritable traits or phenotype of an organism (e.g., eye color).
• Genetics: The study of heredity.
• Genotype: Its genetic makeup, or allele combinations.
• Haploid / Diploid: The number of chromosomes in a gamete of an organism, symbolized by n.
• Heredity: The passing of physical characteristics from parents to offspring. There are also inherited traits: physical characteristics that can be passed down from parent to child and are determined by one or many genes (e.g., eye, hair, and skin color, height, etc.).
• Hybrid / Heterozygous: Has two different alleles for a trait (one dominant and one recessive).
• Interphase: The phase of the cell cycle in which the cell spends the majority of its time and performs the majority of its purposes, including preparation for cell division.
• Meiosis: A special type of cell division necessary for sexual reproduction in eukaryotes, such as animals, plants, and fungi.
• Mitosis: A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
• Phenotype: Its physical appearance, or visible traits.
• Probability: A measure of the likelihood that a statement or a theoretical expectation is correct.
• Punnett Square: A diagram that is used to predict an outcome of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach, and is used by biologists to determine the probability of an offspring having a particular genotype.
• Purebred / Homozygous: Has two identical alleles for a trait (both dominant or both recessive).
• Recessive Allele: A genetic trait that is hidden whenever a dominant allele is present.
• Replication: The process by which a cell makes a copy of its DNA in its nucleus.
• Trait: Characteristics or attributes of an organism that are expressed by genes and/or influenced by the environment.