How many nucleotides make up a signal codon?

How and why organisms are hierarchically classifies

Tay-sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large, complex, undigested lipids. which cellular organelle must be involved in this condition?

Dna in the nucleus carries the genetic code for making proteins in ribosomes. the diagram shows a model of dna. which part of the dna molecule codes for the amino acid sequence in the protein? a) sugar b) phosphate c) deoxyribosed) nitrogen bases