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7.1 adaptation and variation

7.1 adaptation and variation. SBI3U Ms. De Sousa. Only the fittest survive…. What does the saying : «  Only the fittest  survive » mean to you ?. Adaptation and variation.

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7.1 adaptation and variation

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  1. 7.1 adaptation and variation SBI3U Ms. De Sousa

  2. Only the fittest survive… Whatdoes the saying: « Onlythe fittest survive » mean to you?

  3. Adaptation and variation • Organismsthat survive environmental challenges are able to pass on theirgenetic information to offspring. • By passing on the genetic information, theirspecies survive. • The varyinginteractions betweenspeciesand the envrionmental changes causes somespecies to go extinctwhileothersthrive.

  4. adaptations • Adaptations can by structural, behavioural or phsyiological. Structural Adaptation: physical features of an organism like the beak on a bird or the fur on a bear. Behavioral Adaptation: Things organisms do to survive. Physiological Adaptation: changes or chemicalreactionsthatoccurwithin an organism.

  5. camouflage • Manyorganisms are able to camouflage and blend in withtheirenvironmentwhichenablesthem to escape predators.

  6. Adaptations and survival • Organismsundergo a variety of adaptations thatenablethem to survive and escape predators. Adaptation: a structure, behaviour or physiologicalprocessthathelps an organism survive and reproduce in a particularenvironment.

  7. Hibernation • Hibernation is a physiological adaptation. • It allowsorganisms to survive in harsh conditions by keeping warm and preservingtheirenergy

  8. mimicry • Mimicry is a form of structural adaptation, where the animal is able to imitatesomethingotherthanwhatitis. • Butterflies use it as a protection mechanism to trick predators into thinking they are an inedible species.

  9. Mimicry The intention of mimicry is to draw attention to yourself. This is usually achieved, through the presence of bright colours.

  10. Check point!!! Clicker questions 1-2

  11. Development of adaptation • Adaptation is due to gradual , accumulative changesthathelps an organism survive and reproduce. • Adaptations are a result of genetic mutations in an organisms’ DNA. • Thesemutations must beheritablein order for the adaptation to persist.

  12. Development of adapations • As a result of the mutations, there are manyvariations thatappear in the population. • Although a mutation maylead to variation, not all variations become an adaptation. Variations: differencesbetweenindividualswhichmaybe structural, functional or physiological.

  13. Development of adaptation • Depending on the environment, certain variations willpersistwhileothers do not. • If the variation enables an organism to survive in an environment, the organismwillpass on the genetic mutation to theiroffspring. • Thosewho survive have a greater chance of passing on theirgenetic information.

  14. Development of adaptations • Although variations may not play a bigroleat one point in time, as the environment changes, that variation maybecomeuseful to an organism’asurvival. • If thatorganism survives, itis able to pass on that trait to the offpsringallowingthem in turn to survive in such an environment.

  15. Variations withinspecies • Althoughorganisms are part of the samespecies, thereisalot of variation. • Humans have a great deal of variation due to the randomcombinations of allelesthatweinheritfromour parents. • The differentcombinations of allelescontribute to the variation in phenotypes of manyspecies.

  16. Mutations leading to genetic variation • Mutations : changes in the geneticmaterial (i.e. DNA) of an organism • The mutation in the nucleotidesequencecreates new versions of alleles. • All mutations happenspontaneouslywhen DNA iscopied in the S phase.

  17. CGA-CCA-ACG-GCG... Amino Acids Produced:Arginine - Proline - Threonine - Alanine ... CGA-CCA-GAA-CGG-CG... Amino Acids Produced:Arginine - Proline - Glutamic Acid - Arginine ...

  18. Mutations leading to variation • Some mutations can alter the shape and function of a cell. • The organism has mechanismsthat are able to getrid of thesemalfunctioningcells. • If the malfunctioningcellis able to bypassthischeckpoint, itproliferates and accumulatedinto a tumor.

  19. Check point!!! Clicker question 3

  20. MUTATIONS AND SELECTIVE ADAVANTAGE • When the environment changes, certain mutations thatwere once unfavorablecannowbefavourable. • Selectiveadvantage: a geneticadvantagethatimproves an organisms’ chance of survival, usualyl in a changingenvironment. • When an organism has a mutation that has a selectiveadvantage, thatorgnaismisfavored in terms of survival and reproduction.

  21. Check point!!! Clicker question 4

  22. Rapid reproduction and selectiveadvantage • Bacteria and viruses tend to have a rapid rate of reproduction. • Due to the rapid reproduction, a mutationthat has a selectiveadvantagecanbespreadinto a population quickly • Thus, whenthereis a change to the environment, a whole population of bacteriamaybe able to survive. • This mayresult in antibioticresistance.

  23. Antibacterialresistance If a bacteriaundergoes a mutation thatallowsit to survive againstbacterialdrugs, itbecomesresistant to the antibiotic. New populations of bateriawillgrow and beressistant to the medication.

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