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• Genetics is the branch of biology that studies heredity and variation.
• Heredity is the transmission of traits from one generation to another, from parents to offspring.
• Variation is any difference existing between individuals of the same species.
• A gene is the basic physical and functional unit of heredity.
• Genes are made up of DNA.
• A chromosome is a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
• A genome is the complete set of genes or genetic material present in a cell or organism.
• Deoxyribonucleic acid is the hereditary material in humans and almost all other organisms.
• An allele is a variant form of a given gene.
• Phenotype is the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
• Genotype is the set of genes in our DNA which is responsible for a particular trait.
• Homozygous refers to a particular gene that has identical alleles.
• Heterozygous refers to having inherited different forms of a particular gene from each parent.
• Dominant Trait is an inherited characteristic that appears in an offspring if it is contributed from a parent through a dominant allele.
• Recessive Trait is a trait that is expressed when an organism has two recessive alleles, or forms of a gene.
• Gene Expression is the process by which information from a gene is used in the synthesis of a functional gene product.
• Gregor Mendel, known as the "father of modern genetics," was born in Austria in 1822.
• Gregor Mendel, a monk, discovered the basic principles of heredity through experiments in his monastery's garden.
• Gregor Mendel's experiments showed that the inheritance of certain traits in pea plants follows particular patterns, subsequently becoming the foundation of modern genetics and leading to the study of heredity.
• Offspring that are hybrid for a trait will have only the dominant trait in the phenotype.
• Offspring inherit one genetic allele from each parent when sex cells unite in fertilization.
• Crossing a heterozygous tall plant with a heterozygous tall plant results in 100% heterozygous offspring.
• Mendel grew over 10,000 pea plants, keeping track of progeny number and type.
• In garden peas, round peas are dominant to wrinkled peas.
• Mendel's work and his Laws of Inheritance were not appreciated in his time.
• Mendel's experimental results were understood only after the rediscovery of his Laws in 1900.
• Each inherited trait is defined by a gene pair.
• Parental genes are randomly separated to the sex cells so that sex cells contain only one gene of the pair.
• If a homozygous dominant and a homozygous recessive are crossed, the genotype and phenotype of the offspring are unknown.
• In a cross of parents that are pure for contrasting traits, only one form of the trait will appear in the next generation.
• Tall plants are dominant to short plants in the garden pea plant.
• If the parent expressing the dominant trait is heterozygous, there is a 75% chance that an offspring will show at least one of the recessive characteristics.
• If the parent expressing the dominant trait is homozygous, one of the offspring will show the recessive characteristics.
• Genes for different traits are sorted separately from one another so that the inheritance of one trait is not dependent on the inheritance of another.
• Heredity is the transmission of traits from one generation to another.
• Gene is the basic physical and functional unit of heredity.
• Chromosome is a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information.
• Genome is the complete set of genes or genetic material present in a cell or organism.
• Allele is a variant form of a given gene.
• Mutation is the alteration of the nucleotide sequence of the genome of an organism.