genetics Flashcards
Heredity
the passing on of physical or mental characteristics genetically from one generation to another.
Dominant Trait
In genetics, dominance is the phenomenon of one variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second is recessive.
Recessive Trait
Refers to a trait that is expressed only when the genotype is homozygous; a trait that tends to be masked by other inherited traits, yet persists in a population among heterozygous genotypes.
Genes
A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins. … Every person has two copies of each gene, one inherited from each parent.
Alleles
An allele is one of two, or more, forms of a given gene variant. For example, the ABO blood grouping is controlled by the ABO gene, which has six common alleles. Nearly every living human’s phenotype for the ABO gene is some combination of just these six alleles.
Phenotype
In genetics, the phenotype is the set of observable characteristics or traits of an organism. The term covers the organism’s morphology or physical form and structure, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior.
Genotype
The genotype of an organism is its complete set of genetic material. However, the term is often used to refer to a single gene or set of genes, such as the genotype for eye color. The genes partly determine the observable characteristics of an organism, such as hair color, height, etc.
Probability
Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, 0 indicates impossibility of the event and 1 indicates certainty.
Meiosis
Meiosis is a special type of cell division of germ cells in sexually-reproducing organisms used to produce the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome.
Sex chromosomes
A sex chromosome is a type of chromosome that participates in sex determination. Humans and most other mammals have two sex chromosomes, the X and the Y. Females have two X chromosomes in their cells, while males have both X and a Y chromosomes in their cells.
Pedigree
A pedigree chart is a diagram that shows the occurrence and appearance of phenotypes of a particular gene or organism and its ancestors from one generation to the next, most commonly humans, show dogs, and race horses.
DNA
Deoxyribonucleic acid is a molecule composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. DNA and ribonucleic acid are nucleic acids.
Nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid and ribonucleic acid, both of which are essential biomolecules within all life-forms on Earth.
Mutations
In biology, a mutation is an alteration in the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA.
RNA
Ribonucleic acid is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid are nucleic acids.
