Optic components: cornea, lens, vitreous body, and the aqueous body b. Not an optic component of the eye: retina 87. Glaucoma is a state of elevated pressure within the eye that occurs when ___ is obstructed so that the _____ is not reabsorbed as fast as it is secreted. a. Occurs when the scleral venous sinus is obstructed so the aqueous humor is not reabsorbed as fast as it is secreted.
Substitution mutation. Definition. A type of point mutation in which a single nucleotide is substituted with (or exchanged for) a different nucleotide that may result in an altered sequence of amino acid during translation, which may render the newly synthesized protein ineffective. Supplement.
  A mutation is a permanent change in the DNA sequence of a gene.   There are two ways in which a DNA mutation can occur:   1) Mutations can be inherited.This means â¦ that if a parent has a mutation in his or her DNA, then the mutation is passed on to his or her children.   2) Mutations can be acquired.or example, this can happen during crossover during the formation of gametes. Substitution mutations happen when one nucleotide (the smallest unit of DNA) is replaced by another. These are caused by a number of chemicals that look like something in between both of those nucleotides.