In: Science

Submitted By ColoredBeautiful
Words 379
Pages 2
1. In directional selection the distribution of phenotypes forms a bell curve selection against one of the extreme phenotypes causes the distribution to move in one direction to the other. An example might be plants whose flower color is determined by incomplete form population the mean phenotype will be shifted toward white flowers. In disruptive selection the average phenotype is selected against the produces a two-humped bell type curve and the greater distribution is split between the two phenotype extremes.
2. Antibiotic resistant bacteria existed before humans made antibiotics because antibiotics existed before humans made them an example is penicillin which is produced from an antibiotic made by a mold. The mold makes that antibiotic to kill bacteria that would complete for the material the mold gets more its nutrition from that way there were some penicillin resistant bacteria before humans developed it. When non-resistant bacteria are exposed to antibiotic most of them die however because of the bacteria may have a resistance to the antibiotic the bacteria selection the ones that do not have a mutation that helps them to survive die. The ones that do survive and pass on the mutation to the next generation the same process occurs if those bacteria are exposed to a different antibiotic which is how some strains of bacteria become milt-antibiotic resistant.
3. Vertebrates are known to be animals with backbones the following are the evolutionary changes of the vertebrates. Jams – fish before sucked and rubbed on their prey but now. They already have jaws that enable them to more efficacious in getting their prey. Lungs and Limbs – Animals on the sea need to adopt when they look for their preys on land in turn they had evolved to acquiring lungs for breathing and limbs for moving’s. Endothermy – Endo meaning internal and therm meaning temperature this gave…...

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