Abnormalities of companion animals : analysis of heritability / C.W. Foley, J.F. Lasley, G.D. Osweiler.

  • Foley, C. W.
Date:
1979
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Abnormalities of companion animals : analysis of heritability / C.W. Foley, J.F. Lasley, G.D. Osweiler. Source: Wellcome Collection.

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    12 I • INTRODUCTION I—A nucleotide Fig. 1.7. This illustrates how the DNA molecule exactly duplicates itself. The double-stranded DNA separates into two single strands which then assemble other parts to form two double-stranded DNA molecules that are exact duplicates of each other. ribosomal RNA (rRNA). These three RNA molecules are different in struc¬ ture and probably perform separate functions in assembling proteins in the cytoplasm. Another major function of the DNA molecule is to direct the synthesis of specific proteins by ribosomes in the cytoplasm of the cell. The DNA molecule sends the code to the ribosomes by means of mRNA for building a specific protein. Proteins differ from each other in the kind, number, and arrangement of the 20 amino acids found in natural proteins. Single- stranded mRNA transmits the code received from the DNA molecule in the nucleus for building proteins to the ribosomes in groups of three con¬ secutive bases known as triplets, or codons. A codon such as UUG, for ex¬ ample, specifies a particular amino acid, whereas another codon such as