Types of Variation in Genetics

The organism's genetic makeup

The organism's observable traits

A characteristic of an organism (like eye color)

The link between genetic makeup and observable traits is often complex.

A simple relationship between genotype and phenotype, where one allele masks the effect of another.

New gene combinations are one source of variation, but the ultimate source comes from genetic changes.

A genetic disorder causing excessive tissue growth along nerves, potentially leading to blindness.

A genetic situation where the heterozygous phenotype is intermediate between the two homozygous phenotypes.

Genes located close together on the same chromosome that tend to be inherited together.

Genes on different chromosomes or far apart on the same chromosome segregate independently during gamete formation.

One gene affecting many traits.

Interaction between genes where one gene affects the expression of another gene.

Traits that vary continuously over a range of values rather than in distinct categories.

A trait determined by the interaction of multiple genes.

The connection between an organism's genetic makeup (genotype) and its observable traits (phenotype) is often complex.

Phenotype is influenced by the environment.

Height is a phenotype, meaning that it's a trait that can be observed and is influenced by both genetics and environment.

A change in a single DNA nucleotide base pair. A substitution can result in a silent (same amino acid), or missense (different amino acid) mutation.

A point mutation that results in the same amino acid being produced.

A point mutation that results in a different amino acid being produced, possibly changing protein function.

Mutations like point mutations, errors in repair, damage from radiation, or unequal crossing over, are fundamental to generating genetic variation.

Mixing of existing genes during reproduction, like genetic shuffling, leads to new combinations of traits.

A mutation that causes a premature stop codon, interrupting protein synthesis.

A change in a single nucleotide base pair in DNA.

A type of point mutation where one nucleotide is replaced with another.

A type of point mutation where nucleotides are added or removed from the DNA sequence.

A mutation that shifts the reading frame of the genetic code, altering all subsequent codons.

Changes in large segments of chromosomes, such as deletions, duplications, inversions, and translocations.

Loss of a segment of DNA from a chromosome.

A segment of DNA is copied and inserted into the chromosome.

A segment of DNA is reversed.

A segment of DNA from one chromosome is moved to another.

Failure of chromosomes to separate properly during cell division.

A genetic disorder caused by the presence of an extra copy of chromosome 21.