ffi % % 0uestions Write your answers 0n a separate sheet of paper. Compare your cladogram with others in the class. Will

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1 I ffi w Cladistics is ne way scientists classify rganisms. A cladgram shws the nature f evlutinary relatinships that may have ccurred, similar t a family tree. Yu will make a cladgram in this activity. Prcedure 0uestins Part I Display yur set f hardware rganisms and match each ne t the rganisms listed n yur Hardware Write yur answers 0n a separate sheet f paper. Cmpare yur cladgram with thers in the class. Will all crrect cladgrams be the same? Why r why nt? )rganism Key actiuity sheet. Make sure yu have all the rganisms Iisted. Cmpare cladistics with the mre traditinal taxnmy that yu did in the Part I f the lessn. Hw d they Classify yur hardware rganisms int grups. 0n a differ? What are the advantages and disadvantages f separate sheet f paper, make a recrd f yur each methd? classificatins, Iisting the letter fr each rganism yu have classified. Then list the cmmn characteristics f each f yur grups. Part Il Yu will nw use a different methd t classify yur rganisms. Fllw the instructins nlhe Cladgram a v After yu have created and revised a r:ugh draft f Easrcs activity sheet 1 create yur cladgram. yur cladgram, create a final versin t share with the (} cl a ss. When yu have cmpleted yur cladgram, answer the questins.

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3 [- ln cladistics, similar characteristics that cme frm a cmm0n ancestr are used t0 divide rganisms int grups. A cladgram will begin by gruping rganisms based n a characteristic displayed by all the members f the grup. Subsequently, the larger grup, r clade, will cntain increasingly smaller grups (clades) that share the traits f the clades befre them. but als exhibit distinct changes as the rganism evlves. The example that fllws represents a cladgram. hair I d e ri v ed ch ara cte ri st i c ) limbs ( d e riv e d c h ara cteri sti c ) laws ( de r i v e d c h a ra cte risti c ) T make a cladgram, scientists first cllect data n the features f all the rganisms they hpe t classify. This data is then analr4ed t determine which characteristics were present in what culd have been a cmmn ancestr and which might have been develped in later times. Use the fllwing instructins t make a cladgram fr yur set f hardware rganisms. Prcedure tvtake yur cladgram 0n a separate sheet f paper. Lay ut yur rganisms n a wrk surface. List all the characteristics yu see fr each bject and make a table f all the traits. Wnicfr characteristic d all the bjects have in cmmn? This is referred t as a primitive, r riginal, characteristic. lt is f little value in analyzing the relatinships within a grup since all members pssess this characteristic. Again lk at the data t determine cmmn characteristics that nly a prtin f the grup has. These are referred t as derived, r advanced, characteristics. They are usually mre advanced features that were added t the primitive features fund earlier. The largest grup f these derived characteristics will be the first t branch frm the main trunk f the cladgram. Name the derived characteristic and list all the bjects that have that characteristic. Yur drawing f the cladgram at this pint shuld lk similar t the fllwing: ' Sample Cladgram ( pri m it ive cha ra cteristi c) I ) I V, characteristic Y;:::':,2,,,,," Lk fr further characteristics that are cmmn t nly a prtin f the grup and add these t the cladgram until the graups can be srted n further. Surce: Science al a 0istance-*Prfessr Jhn Blamire {M.brmklyn.cuny.edu/bclahp/CLAS/CLAS.Clad.html }

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