Genetics & Inheritance Flashcards
Traits
Characteristics or attributes of an organism that are expressed by genes and/or influenced by the environment.
Heredity
The passing of genetic factors from parent to offspring (or from one generation to the next).
Dihybrid cross
is a cross between two different lines/genes that differ in two observed traits.
Phenotype
the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
F1 generation
The parental generation (P) is the first set of parents crossed. The F1 (first filial) generation consists of all the offspring from the parents
Allele
An allele is one of the possible forms of a gene. Most genes have two alleles, a dominant allele and a recessive allele. If an organism is heterozygous for that trait, or possesses one of each allele, then the dominant trait is expressed. A recessive allele is only expressed if an organism is homozygous for that trait, or possesses two recessive alleles. Alleles were first defined by Gregor Mendel in the law of segregation.
Incomplete dominance
Incomplete dominance is when a dominant allele, or form of a gene, does not completely mask the effects of a recessive allele, and the organism’s resulting physical appearance shows a blending of both alleles. It is also called semi-dominance or partial dominance
Monohybrid Cross
A genetic cross between parents that differ in the alleles they possess for one particular gene, one parent having two dominant alleles and the other two recessives. All the offspring have one dominant and one recessive allele for that gene.
Dominant
An allele or a gene that is expressed in an organism’s phenotype, masking the effect of the recessive allele or gene when present.
Independent Assortment
formation of random combinations of chromosomes in meiosis and of genes on different pairs of homologous chromosomes by the passage according to the laws of probability of one of each diploid pair of homologous chromosomes into each gamete independently of each other pair.
Recessive
A recessive trait is a trait that is expressed when an organism has two recessive alleles, or forms of a gene.
Heterozygous
having two different alleles of a particular gene or genes
Genes
The fundamental, physical, and functional unit of heredity
Genotype
The genotype of an organism is the chemical composition of its DNA, which gives rise to the phenotype, or observable traits of an organism. A genotype consists of all the nucleic acids present in a DNA molecule that code for a particular trait.
Law of Segregation
Mendel’s Law of Segregation states that a diploid organism passes a randomly selected allele for a trait to its offspring, such that the offspring receives one allele from each parent.
Co-dominant
Co-dominance is a form of dominance where in the alleles of a gene pair in a heterozygote are fully expressed. This results in offspring with a phenotype that is neither dominant nor recessive. A typical example showing co-dominance is the ABO blood group system.
F2 Generation
The filial generation comprised of offspring(s) resulting from a cross between two individuals from the first filial generation.
Punnett square
A Punnett square is a graphical representation of the possible genotypes of an offspring arising from a particular cross or breeding event.
Sex-Linked
Determined by a gene located in a sex chromosome
Homozygous
Having identical pairs of genes for any given pair of hereditary characteristics
Gamete
Sex cells(ova, sperm)
Genetics
the genetic properties or features of an organism and characteristics.
