Answer:
Mechanical barriers — which include the skin , mucous membranes , and fluids such as tears and urine — physically block pathogens from entering the body. Chemical barriers — such as enzymes in sweat , saliva , and semen — kill pathogens on body surfaces.
Lemon juice is 10,000 more acidic than urine
For example: GGATACCTAGGTAAT
Insertion: GGAT<u>G</u>ACCTAGGTAAT
a nucleotide that was not present before is inserted into the original sequence
Substitution: <u>C</u>GATACCTAGGTAAT
the first nucleotide was substituted in for another (C for G)
Frameshift (basically a insertion or deletion, we'll try deletion here): GATACCTAGGTAAT
the first nucleotide was deleted, causing the reading frame to be shifted (instead of GGA as the first codon, we have GAT)
Genetically modified crops are genetically engineered such that a desired trait is enhanced or reproduced to appear in every offspring. Genetically engineered corn has been engineered to resist pests and herbicides; thus, we have more yield and many people especially in the low class society can afford. A disadvantage, yet is still a debate, is that genetically engineered crops such as corn, has toxic effects to internal organs such as our liver, a vital internal organ.