University:
Sam Houston State University
Course:
BIOL 1406 | General Biology I
Academic year:

2022
Views:

358

Pages:

14
Author:

SpaceCadet101

The Gene • Component of DNA – deoxyribonucleic acid • Large double stranded polymer of units called nucleotides • Nucleotide –Sugar – deoxyribose –Phosphate group –Nitrogeneous base • adenine guanine • cytosine thymine Transcription of RNA • Bases in DNA code for transcription of RNA • RNA – ribonucleic acid –Also nucleic acid –Single stranded –Uracil instead of thymine –Ribose instead of deoxyribose RNA • Three primary types of RNA • Messenger RNA –Transfers code from DNA to protein synthesis • Transfer RNA –Carries amino acids to the ribosome • Ribosomal RNA –Forms part of the structure of the ribosome Translation of RNA • RNA binds with ribosome • Ribosome is location of protein synthesis • Information on RNA used to generate amino acid sequence in proteins Genetic Code • Each amino acid coded by a three base sequence (codon) • Most amino acids have more than one codon • One codon specifies beginning of a protein • Three codons specify the end of a protein Control of Gene Function • Complete gene is actually a complex of different types of genes (complex called an operon) • Structural genes –Code for actual protein sequence • Regulatory genes –Affect function of the structural genes Interactions Between Genes • Epistasis –Two or more gene pairs (not alleles) in which one gene pair influences expression of another gene pair – may or may not be on homologs • Example: Horned, polled, scurred –Two gene pairs (horned vs polled) (smooth vs scurred) –If horned – scurred vs smooth does not matter –If polled – scurred vs smooth can express Genes and Embryological Development • After union of sperm and egg –Cell division occurs –Early development - all cells are alike –Subsequent development – cells differentiate –Embryological development is genetically controlled Genes and Embryological Development • Lethal genes –Genes which stop development –Many must be received from both parents to cause death –Cause of high percentage of embryonic death Biotechnology • Biotechnology –All technologies that pertain to molecular manipulation of living material –Very difficult word to characterize • Genetic engineering –New methods for modifying the animal genome Microbe Engineering • Recombinant DNA Technology –Segment of DNA removed from species of interest –Segment is inserted into a microorganism –Microorganism makes the product specified by the DNA –DNA is “recombined” into a new location Recombinant DNA • Used for production of: –Bovine growth hormone to increase milk production –Vaccines –Other pharmaceuticals –Bacteria to consume oil spills or other pollutants Transgenesis • Transgenesis –Movement of genes from one species into another –First use – development of mouse with extra genes for growth hormone Genetic Engineering in Plants • Round-up-ready crops –Several crop species have been engineered to be resistant to the herbicide Round-up • Bt crops –Corn and cotton have genes from a microbe that causes them to be resistant to corn borer and boll weevil • Flavr-Savr tomato –Gene altered to lengthen shelf life