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Mendel and the Gene Idea Chromosomal Basis of Inheritance - Coggle Diagram
Mendel and the Gene Idea Chromosomal Basis of Inheritance
Mendel
"Father of Genetics" studied inheritance traits in pea plants
Character
vs
Trait
character is an observable heritable feature that may vary among individuals whereas trait is one of two or more detectable variants in a genetic character
True Breeding
Referring to organisms that produce offspring of the same variety over many generations of self-pollination
hybridization
In genetics, the mating, or crossing, of two true-breeding varieties
P
generation = parental
F1
generation = first filial
F2
generation = second filial
Law of Segregation
dominant allele
An allele that is fully expressed in the phenotype of a heterozygote
recessive allele
An allele whose phenotypic effect is not observed in a heterozygote
Important Vocabulary
homozygote
An organism that has a pair of identical alleles for a gene
homozygous
Having two identical alleles for a given gene
heterozygote
An organism that has two different alleles for a gene
heterozygous
Having two different alleles for a given gene
phenotype
The observable physical and physiological traits of an organism, which are determined by its genetic makeup
genotype
The genetic makeup, or set of alleles, of an organism
Law of Independent Assortment
monohybrid
An organism that is heterozygous with respect to a single gene of interest. All the offspring from a cross between parents homozygous for different alleles are monohybrids. For example, parents of genotypes AA and aa produce a monohybrid of genotype Aa
dihybrid
An organism that is heterozygous with respect to two genes of interest. All the offspring from a cross between parents doubly homozygous for different alleles are dihybrids. For example, parents of genotypes AABB and aabb produce a dihybrid of genotype AaBb
complete dominance
phenotypes of the heterozygote and dominant homozygote are indistinguishable
incomplete dominance
phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele
Chromosomal Basis of Inheritance
A basic principle in biology stating that genes are located at specific positions (loci) on chromosomes and that the behavior of chromosomes during meiosis accounts for inheritance patterns
The chromosomal basis of Mendel’s laws
sex-linked gene
A gene located on either sex chromosome. Most sex-linked genes are on the X chromosome and show distinctive patterns of inheritance; there are very few genes on the Y chromosome
X-linked gene
A gene located on the X chromosome; such genes show a distinctive pattern of inheritance
linked genes
Genes located close enough together on a chromosome that they tend to be inherited together
genetic recombination
General term for the production of offspring with combinations of traits that differ from those found in either parent
crossing over
The reciprocal exchange of genetic material between nonsister chromatids during prophase I of meiosis.
Abnormal Chromosome numbers
nondisjunction
An error in meiosis or mitosis in which members of a pair of homologous chromosomes or a pair of sister chromatids fail to separate properly from each other
aneuploidy
chromosomal aberration in which one or more chromosomes are present in extra copies or are deficient in number
monosomic
Referring to a diploid cell that has only one copy of a particular chromosome instead of the normal two
trisomic
Referring to a diploid cell that has three copies of a particular chromosome instead of the normal two
polyploidy
chromosomal alteration in which the organism possesses more than two complete chromosome sets. It is the result of an accident of cell division
Alternations in Chromosomal Structure
