They are mobile structures, found externally in cells of various living beings. Eyelashes are short and may be related to locomotion and the removal of impurities. In cells lining the human trachea, for example, the ciliary beats push impurities from the inspired air, work facilitated by mixing with mucus that, produced by the trachea cells, lubricates and protects the trachea.

Let us now briefly describe two important diseases related to the action of “defective” genes. Phenylketonuria Phenylketonuria (PKU) is a genetic disease due to the action of a recessive gene that manifests in homozygosis, affecting approximately 1 in 12,000 newborns in Brazil.

New research suggests that mammals may be more genetically similar to their parents than to their mothers, although we inherit equal amounts of genetic mutations from each parent. The University of North Carolina (UNC) study found that the influence of mutant genes coming from the father is greater than the mutant genes from the mother.

The propagation velocity of nerve stimuli in the membrane of a neuron ranges from 10cm / s to 1m / s. Such speeds, however, are insufficient to coordinate the actions of large animals. In a giraffe, for example, a pulse traveling at a speed of 1m / s would take between three and four seconds to travel the distance from the hind paw to the brain.

Bateson and Punnet's pea flower color described another case of gene interaction by analyzing flower color inheritance in pea plants. The flowers on these plants may be white or purple in color. Crossing two white flowering plants of different origins, they obtained in F 1 only purple flowering plants.

It is not known exactly who invented the microscope but it is well known that after this invention, around the beginning of the seventeenth century, our perception of the world was very different. Many attribute the invention of this instrument to Galileo, but it was Leeuwenhoek who really perfected the instrument and used it in the observation of living beings.