homework1

homework1 - 7.36/7.91/BE.490 Homework 1 Due February 24 at...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 7.36/7.91/BE.490 Homework 1 Due February 24 at 1:00 PM Note: Please see the class website for a handout describing how to submit your programming problems electronically. 1. Use of Entrez Hexokinase is the enzyme that converts glucose to glucose6-phosphate in the first step of glycolysis. You heard a relative (non-biologist) saying he had a mutation in the hexokinase 4 gene that caused his disease. You are curious to know more about it and go to your favorite site. a. Go to the protein section of Entrez and do a search that limits your results to matches for `hexokinase' that are specific to humans and that in the text contain the word `disease'. What disease was your relative talking about? b. Click on the `Blink' link to see related proteins. How many Metazoan species show a match with the default parameters? c. Look at the "Best hits". How similar is the frog (Xenopus laevis) hexokinase to the human hexokinase? What is the difference between "Identities" and "Positives"? To learn more about hexokinase, go back to the protein record page, click on "Links" and "Map Viewer". d. What chromosome and chromosomal region is the gene on? Click on the OMIM link. What is OMIM? Read the information provided. Given what you now know about hexokinase 4, does it make sense that a mutation in this gene causes that disease? Explain briefly. As indicated in the OMIM record, Danial et al. found an unexpected link between the pro-apoptotic protein BAD and hexokinase. The accession number for BAD is Q61337. e. Go to about i) ii) iii) Swissprot (expasy.org) to find more information this protein. What is its subcellular localization? What domain/s does it contain? Find the molecular weight for this protein. 2. BLAST You have recently isolated and sequenced your favorite gene (yfg). Yeast mutants in this gene are unable to grow in fructose. You saved the protein sequence onto your hard drive but gave the file an undescriptive name. You know that you only saved two sequences that day. Unfortunately, one of them was a random sequence you generated for assessing the significance of alignments in an unrelated project. You would like to decide which sequence is random and which one is that of yfg. The two sequences are provided below in FASTA format: > sequence 1 MPDHDFIDFWIMCAETVEYRVLLGCGEWDAIQVNEHFAIPCSYRSFEGRYPMTTQQTYLTPHQIWLCQMFRCYFEPAHG ACKTVARTRYQRHVHCRYEKCALESPAVSWSIHMNSSLTLFNQQWSRVYMPSKMEDFDDLSGFWANMQHFKGQWHNDEG NLYFLMSEWWASWTWEQWGFDIPNVEGHDVVPLLQNEISKRELPLCTEKAHVTHVLNPQPQMRMTDPETKHNPAYVQKR PGVDGCIHWTGAANRTPGDQWTWHGMEFFQCFQHHRYDCDEWDPGFRMWHRWNVRIREYESPEAGYYFYQCNIFECASA VIRYEEHAIASYLKDQDLSKLKQPYIMDTSYPARIEDDPFVFLEDTDDIFQKDFGVKTTLPERKLIRRLCEYSETEAAR LAVCGIAAICQKRGYKTGHIAADGSVYNKYPGFKEAPQSHEVHRKIMEMPATTQPITIVPAEDGSGAGAAVIAALSEKR IAEGKSLGIIGA > sequence 2 PHYRKRGKWQFTPDFPPINLAAHAIQCAPPAAENCIPRQCLKIEQQRLNDLRVGGVFTWFFACPETEEYKHHIINDALV WGEVFPYQVADTKVRQHEEEKVLTLLLKWAGAQQYNKEPRIAKSSWTIPREWNPFMWHQIPQIKQTIKNNRMSLERYTR LDQIDNTQYYCIMGNANRYSRKPTCWWPGVMRKYCNGVHQCILKNPDVSSTQFGPMCCGKLWNHLNETYNATPRCKIET TLYDVSKPYPFIELKLPCHPEPFNMLMWHKHKGIMRHDKLAQRGGRSYLWLTTEIMRNLKCKIHVSWNANTYFRMWRFK EYIASVGGWDWRTFLCVNHIVICEANDMDSITANWGVDCFWCGYFLGQYSQDCAGTYATPNFTGSQFPPQEPEMPQQVA HSHWQCCAFMLRNMCEIGSHPYMWTWDTWEDSRQSQVGKFACVHLWFVQVLYIMEMKQQYEDNYAVAMERGWDMVWHKL DDMRIIGVPFYA a. Go to http://www.ncbi.nlm.nih.gov/BLAST/ and click on "Protein-protein BLAST (blastp)". Run each of the sequences against the nr database with default parameters. Answer the following questions for each of the sequences: i) What is the E-value, the bit score, and the raw score of the best scoring match? ii) At the bottom of the BLAST results page, you will find two sets of values for l, K, and H one for gapped and one for ungapped alignments. According to the bit and the raw scores, which set of values for l, K, and H do you think was used? What bit score would the top scoring hit get had the other set of values been used? Show your work. iii) Judging by the top scoring hit, which of the two sequences is likely yfg? Why? iv) Does your guess in part (iii) make sense in terms of what you know about the phenotype of yeast deficient in this gene? b. Assuming that you have correctly identified your gene, go back and BLAST it again, but this time with gap costs of 10 for opening and 1 for extending. How does this change your results? Explain. c. Go back to the main BLAST page and click on "Align two sequences (bl2seq)". Blast yfg against the top scoring hit you identified above using the blastp program and the BLOSUM62 matrix, the PAM 250 matrix and the PAM 30 matrix. Write down the bit scores and the E values for each one. Why are they different? Be sure to explain what the E value means and why it is so much larger for the PAM250 search than for the PAM30 search. 3. Programming in Python Write a program in python that does all of the following a. Accepts the name of a file on the command line. This file will contain two DNA sequences in FASTA format. b. Prints the following statistics concerning each sequence to the screen i) length ii) % GC content iii) % of purines iv) % of pyrimidines c. Sends the amino acid translation of each DNA sequence to the screen in FASTA format. d. Finds all 8 residue long regions that are identical between the two proteins and prints 8 residue sequence as well as the starting coordinate of this region in both proteins to the screen. It is always a good idea to perform error checking in your code, but for this assignment it is not required. You can assume that the program is called with exactly one argument, which is the name of an existing file, which indeed contains two DNA sequences in FASTA format (i.e. no errors on the part of the user). The following is a sample run of the program. Please try to match your program input and output formatting as closely as possible to the example below. [computer] ~/TA/7.91/ps1$ cat input_example.fasta >Random Coding Sequence 1 ATGCAAAGGCCAGGCAAGAAAGTGGCTGCTGATTCAGAGGAATCAAATGACATCAGCCAACAAGCAGAAA ACAGAGACCAGCTCCTCCCCCAGGAAGCCAGTCCCAAAGCGTGTGAGGAAGAGGACACAGAGGAACACCG CAAAGGGGTAACAAGCCGCAGGAAAAGAAGGCCCCCCAGAAGGCAGACAGCCCCTTAA >Random Coding Sequence 2 ATGGTGGTGAGGAAGAGGACACAGAGGAGCGGTCAAAGGCCAGGCAAGAAAGTGGCTGTGTCTGCCGGGG TGGGAAGAGGACACAGAGGATCCGCGCGGACCTCGCCCAGCTCAGATAAAGTACAGAAAGACAAGGCTGA ACTGATCTCAGGGCCCAGGCAGGACAGCCGAATAGGGAAACTCTTGGGTTTTGAGTGGACAGATTTGTCC AGTTGGCGGAGGCTGGTGACCCTGCTGAATCGACCAACGGACCCTGCAAGCCAAAGGCCAGGCAAGAAAG TGGCTTGA [computer] ~/TA/7.91/ps1$ python reshmahw1.py input_example.fasta Random Coding Sequence 1 Length = 198 percent GC content = 54.04 percent purine content = 64.65 percent pyrimidine content = 35.35 Random Coding Sequence 2 Length = 288 percent GC content = 56.94 percent purine content = 63.19 percent pyrimidine content = 36.81 >Random Coding Sequence 1 MQRPGKKVAADSEESNDISQQAENRDQLLPQEASPKACEEEDTEEHRKGVTSRRKRRPPRRQTAP* >Random Coding Sequence 2 MVVRKRTQRSGQRPGKKVAVSAGVGRGHRGSARTSPSSDKVQKDKAELISGPRQDSRIGKLLGFEWTDLSS WRRLVTLLNRPTDPASQRPGKKVA* The sequence QRPGKKVA is found starting at amino acid position(s) [12, 88] in sequence "Random Coding Sequence 2" and at amino acid position(s) [2] in sequence "Random Coding Sequence 1". Name this file dnaanalysis.py and submit it online. Your program will be tested on MIT Server. Please make sure that your program runs correctly there. 4. Dot Matrix a. Using a dot matrix program (Dotlet at http://www.isrec.isb-sib.ch/java/dotlet/Dotlet.html), compare the following sequence to itself. What can you say about its primary structure? (use the scoring matrix blosum62). You will need to adjust the window, grayscale and zoom. MPCFYLRSCGSLLPELKLEERTEFAHRIWDTLQKLGAVYDVSHYNALLKVYLQNEYKFSP TDFLAKMEEANIQPNRVTYQRLIASYCNVGDIEGASKILGFMKTKDLPVTEAVFSALVTG HARAGDMENAENILTVMRDAGIEPGPDTYLALLNAYAEKGDIDHVKQTLEKVEKFELHLM DRDLLQIIFSFSKAGYLSMSQKFWKKFTCERRYIPDAMNLILLLVTEKLEDVALQILLAC PVSKEDGPSVFGSFFLQHCVTMNTPVEKLTDYCKKLKEVQMHSFPLQFTLHCALLANKTD LAKALMKAVKEEGFPIRPHYFWPLLVGRRKEKNVQGIIEILKGMQELGVHPDQETYTDYV IPCFDSVNSARAILQENGCLSDSDMFSQAGLRSEAANGNLDFVLSFLKSNTLPISLQSIR SSLLLGFRRSMNINVWSEITELLYKDGRYCQEPRGPTEAVGNFLYNLIDSMSDSEVQAKE EHLRQYFHQLEKMNVKIPENIYRGIRNLLESYHVPELIKDAHLLVERKNLDFQKTVQLTS SELESTLETLKAENQPIRDVLKQLILVLCSEENMQKALELKAKYESDMVTGGYAALINLC CRHDKVEDALNLKEEFDRLDSSAVLDTGNYLGLVRVLAKHGKLQDAIKILKEMKEKDVLI KDTTALSFFHMLNGAALRGEIETVKQLHEAIVTLGLAEPSTNISFPLVTVHLEKGDLSTA LEVAIDCYEKYKVLPRIHDVLCKLVEKGETDLIQKAMDFVSQEQGEMVMLYDLFFAFLQT GNYKEAKKIIETPGIRARSARLQWFCDRCVANNQVETLEKLVELTQKLFECDRDQMYYNL LKLYKINGDWQRADAVWNKIQEENVIPREKTLRLLAEILREGNQEVPFDVPELWYEDEKH SLNSSSASTTEPDFQKDILIACRLNQKKGAYDIFLNAKEQNIVFNAETYSNLIKLLMSED YFTQAMEVKAFAETHIKGFTLNDAANSRLIITQVRRDYLKEAVTTLKTVLDQQQTPSRLA VTRVIQALAMKGDVENIEVVQKMLNGLEDSIGLSKMVFINNIALAQIKNNNIDAAIENIE NMLTSENKVIEPQYFGLAYLFRKVIEEQLEPAVEKISIMAERLANQFAIYKPVTDFFLQL VDAGKVDDARALLQRCGAIAEQTPILLLFLLRNSRKQGKASTVKSVLELIPELNEKEEAY NSLMKSYVSEKDVTSAKALYEHLTAKNTKLDDLFLKRYASLLKYAGEPVPFIEPPESFEF YAQQLRKLRENSS b. Draw a sketch Dot Matrix plot for: i) Sequence a vs. Sequence a ii) Sequence a vs. Sequence b Assume the residues between blocks are unrelated in sequence (and ignore matches involving these sequences). Use a window length of 1. Sequence a 80 160 240 320 400 480 0 Sequence b c. Briefly explain (don't draw) how the plots will change if you instead use a window of size 10 and stringency of 10/10. 5. Dynamic Programming Suppose that your professor suddenly wants an alignment of two proteins from different species for use in a grant proposal that is due by the end of the day. The entire campus is experiencing a network outage meaning you can't use any web servers to do the alignment. a. Use the BLOSUM62 matrix and the Needleman-Wunsch algorithm to provide an alignment of two short regions of the proteins shown below. Create and fill in a dynamic programming matrix for the two sequences as shown in class. Assume a linear gap penalty of 8 for each gap. Show how you moved from each square to the next. Circle the traceback as done in class and show the optimal alignment. Please use sequence 1 on the top of the matrix and sequence 2 on the left-hand side. Sequence 1: Sequence 2: INMWGAF VSTEWGD b. Suppose that your professor isn't satisfied with the alignment and wants to see the resulting alignment from the Smith-Waterman algorithm. Does using this algorithm change the alignment as compared to your answer in part (a)? Why or why not? Note: you do not have to repeat the creation of the matrix. Just describe in words how the alignment changes and what about the algorithm causes the change. Also, how does the score of the resulting alignment change in this situation? c. Once you email your professor the alignment, he/she soon returns and demands to know why you chose to use the BLOSUM62 matrix rather one of the PAM matrices. Explain the differences between the BLOSUM62 scoring matrix and the PAM matrices that should be taken into account when generating alignments. 6. Amino acid substitution matrices According to the entries in the PAM1 matrix, the probability that an amino acid will mutate is ~0.98% (thus, the probability that it will not mutate is ~99.02%). a. Write a python program, which takes two command line parameters: the name of a file containing a PAM1 matrix and an integer n. The program should then read in the matrix from the file and calculate the PAMn matrix. It then should output the resulting matrix one row per line separating entries with spaces. Although it is always good to perform error checking in your code, it is not required for this assignment. You can assume that the program is called with exactly two parameters: 1) the name of an existing file, which indeed contains a square matrix and 2) a positive integer. Below is a sample run of the program. Make your output look as close to the output below as possible. In particular when printing out matrices multiply the entries by 10000 and display them as integers (this makes the high probability pairs more apparent). [computer] ~/TA/7.91/ps1$ cat PAM1.txt 0.9867 0.0002 0.0009 0.0010 0.0003 0.0008 0.0017 0.0021 0.0002 0.0006 0.0004 0.0001 0.9913 0.0001 0.0000 0.0001 0.0010 0.0000 0.0000 0.0010 0.0003 0.0001 0.0004 0.0001 0.9822 0.0036 0.0000 0.0004 0.0006 0.0006 0.0021 0.0003 0.0001 0.0006 0.0000 0.0042 0.9859 0.0000 0.0006 0.0053 0.0006 0.0004 0.0001 0.0000 0.0001 0.0001 0.0000 0.0000 0.9973 0.0000 0.0000 0.0000 0.0001 0.0001 0.0000 0.0003 0.0009 0.0004 0.0005 0.0000 0.9876 0.0027 0.0001 0.0023 0.0001 0.0003 0.0010 0.0000 0.0007 0.0056 0.0000 0.0035 0.9865 0.0004 0.0002 0.0003 0.0001 0.0021 0.0001 0.0012 0.0011 0.0001 0.0003 0.0007 0.9935 0.0001 0.0000 0.0001 0.0001 0.0008 0.0018 0.0003 0.0001 0.0020 0.0001 0.0000 0.9912 0.0000 0.0001 0.0002 0.0002 0.0003 0.0001 0.0002 0.0001 0.0002 0.0000 0.0000 0.9872 0.0009 0.0003 0.0001 0.0003 0.0000 0.0000 0.0006 0.0001 0.0001 0.0004 0.0022 0.9947 0.0002 0.0037 0.0025 0.0006 0.0000 0.0012 0.0007 0.0002 0.0002 0.0004 0.0001 0.0001 0.0001 0.0000 0.0000 0.0000 0.0002 0.0000 0.0000 0.0000 0.0005 0.0008 0.0001 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 0.0001 0.0002 0.0008 0.0006 0.0013 0.0005 0.0002 0.0001 0.0001 0.0008 0.0003 0.0002 0.0005 0.0001 0.0002 0.0028 0.0011 0.0034 0.0007 0.0011 0.0004 0.0006 0.0016 0.0002 0.0002 0.0001 0.0022 0.0002 0.0013 0.0004 0.0001 0.0003 0.0002 0.0002 0.0001 0.0011 0.0002 0.0000 0.0002 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0003 0.0000 0.0003 0.0000 0.0001 0.0000 0.0004 0.0001 0.0001 0.0013 0.0002 0.0001 0.0001 0.0003 0.0002 0.0002 0.0003 0.0003 0.0057 0.0011 [computer] ~/TA/7.91/ps1$ python pamn.py PAM1.txt 120 PAM1 is: 9867 2 9 10 3 8 17 21 2 6 4 2 6 1 9913 1 0 1 10 0 0 10 3 1 19 4 4 1 9822 36 0 4 6 6 21 3 1 13 0 6 0 42 9859 0 6 53 6 4 1 0 3 0 1 1 0 0 9973 0 0 0 1 1 0 0 0 3 9 4 5 0 9876 27 1 23 1 3 6 4 10 0 7 56 0 35 9865 4 2 3 1 4 1 21 1 12 11 1 3 7 9935 1 0 1 2 1 1 8 18 3 1 20 1 0 9912 0 1 1 0 2 2 3 1 2 1 2 0 0 9872 9 2 12 3 1 3 0 0 6 1 1 4 22 9947 2 45 2 37 25 6 0 12 7 2 2 4 1 9926 20 1 1 0 0 0 2 0 0 0 5 8 4 9874 1 1 1 0 0 0 0 1 2 8 6 0 4 13 5 2 1 1 8 3 2 5 1 2 2 1 28 11 34 7 11 4 6 16 2 2 1 7 4 22 2 13 4 1 3 2 2 1 11 2 8 6 0 2 0 0 0 0 0 0 0 0 0 0 0 1 0 3 0 3 0 1 0 4 1 1 0 0 13 2 1 1 3 2 2 3 3 57 11 1 17 PAM120 is: 2658 331 727 735 327 583 830 1113 343 580 365 378 463 151 3796 254 130 101 517 154 78 553 193 119 968 300 343 257 1626 928 83 371 527 372 700 180 104 529 143 417 147 1078 2578 51 598 1547 432 409 153 74 331 105 118 95 65 33 7262 34 32 45 90 106 26 34 36 242 471 353 489 37 2605 892 150 926 135 193 377 232 486 185 640 1632 50 1161 2691 369 386 208 130 337 162 1124 227 779 788 197 387 648 4904 255 223 168 308 212 135 446 597 296 88 804 251 79 3705 77 104 204 83 225 149 166 119 155 128 140 85 92 2611 555 165 603 313 197 253 129 68 407 181 155 343 1344 5601 265 2181 352 1881 1030 596 80 774 567 284 465 343 198 4531 923 77 95 55 32 17 100 41 29 41 252 386 184 2331 109 91 116 43 58 55 45 94 178 439 450 47 307 658 367 291 229 143 471 305 283 369 175 188 240 174 1024 546 962 602 580 412 511 832 354 309 181 527 314 886 303 629 401 197 306 339 384 225 548 234 492 394 11 134 13 5 7 10 5 7 12 8 6 18 8 88 37 157 56 239 52 74 37 256 138 134 31 70 612 207 233 192 262 236 234 281 229 2058 794 198 927 [computer] ~/TA/7.91/ps1$ 0.0002 0.0019 0.0013 0.0003 0.0000 0.0006 0.0004 0.0002 0.0001 0.0002 0.0002 0.9926 0.0004 0.0000 0.0002 0.0007 0.0008 0.0000 0.0000 0.0001 2 1 1 0 0 0 0 1 2 7 13 0 1 9946 1 3 1 1 21 1 223 96 112 47 43 54 53 134 162 389 966 89 94 5509 113 213 156 89 1358 264 0.0006 0.0004 0.0000 0.0000 0.0000 0.0004 0.0001 0.0001 0.0000 0.0012 0.0045 0.0020 0.9874 0.0004 0.0001 0.0004 0.0006 0.0000 0.0000 0.0017 22 4 2 1 1 6 3 3 3 0 3 3 0 0 9926 17 5 0 0 3 1124 291 244 221 116 349 304 475 230 96 278 370 39 44 4307 847 491 10 34 298 0.0002 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 0.0001 0.0002 0.0007 0.0013 0.0000 0.0001 0.9946 0.0001 0.0003 0.0001 0.0001 0.0021 0.0001 0.0022 0.0004 0.0002 0.0001 0.0001 0.0006 0.0003 0.0003 0.0003 0.0000 0.0003 0.0003 0.0000 0.0000 0.9926 0.0017 0.0005 0.0000 0.0000 0.0003 0.0035 0.0006 0.0020 0.0005 0.0005 0.0002 0.0004 0.0021 0.0001 0.0001 0.0001 0.0008 0.0001 0.0002 0.0012 0.9840 0.0032 0.0001 0.0001 0.0002 2 0 4 0 3 0 1 0 4 1 2 1 0 28 0 2 2 1 9945 2 206 54 205 78 238 59 91 88 263 151 327 131 29 1806 60 203 175 90 5404 193 0.0032 0.0001 0.0009 0.0003 0.0001 0.0002 0.0002 0.0003 0.0001 0.0007 0.0003 0.0011 0.0002 0.0001 0.0004 0.0038 0.9871 0.0000 0.0001 0.0010 18 1 1 1 2 1 2 5 1 33 15 1 4 0 2 2 9 0 1 9901 859 125 155 158 155 132 206 434 95 1186 1078 229 220 141 231 351 546 4 96 3620 0.0000 0.0008 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0004 0.0000 0.0000 0.0003 0.0000 0.0005 0.0000 0.9976 0.0002 0.0000 0.0002 0.0000 0.0004 0.0000 0.0003 0.0000 0.0001 0.0000 0.0004 0.0001 0.0002 0.0001 0.0000 0.0028 0.0000 0.0002 0.0002 0.0001 0.9945 0.0002 0.0018 0.0001 0.0001 0.0001 0.0002 0.0001 0.0002 0.0005 0.0001 0.0033 0.0015 0.0001 0.0004 0.0000 0.0002 0.0002 0.0009 0.0000 0.0001 0.9901 35 6 20 5 5 2 4 21 1 1 1 8 1 2 12 9840 32 1 1 2 1279 302 568 416 266 216 363 1076 173 158 212 601 71 137 603 2086 1033 54 98 321 32 1 9 3 1 2 2 3 1 7 3 11 2 1 4 38 9871 0 1 10 1302 197 438 323 130 198 296 580 143 345 348 671 114 124 411 1225 2589 14 96 600 0 8 1 0 0 0 0 0 1 0 4 0 0 3 0 5 0 9976 2 0 86 538 92 33 18 49 28 60 108 38 349 145 21 277 51 291 72 7507 190 47 Name this program pamn.py and submit it online. Your program will be tested on MIT Server. Please make sure that your program runs correctly there. b. In the sample run above, the program calculates the PAM120. From the values in this matrix (keeping in mind that the entries are multiplied by 10000) calculate the average probability of amino acid conservation. 7. Phylogenetic analysis Suppose you are studying a set of proteins, which have a conserved BLOCKS motif. You would like to establish a phylogenetic relationship between these proteins. In order to do this, you decide to look at the degree of divergence among the nucleotide sequences coding for the conserved motif. You obtain these sequences and they look as follows: HXK_PLAFA: HXK_SCHMA: HXK1_BOVIN: HXK1_HUMAN: HXK1_TOBAC: AAA GTC ATG ATG ATG ATT GTC TGC TGC GTT ATA ATA ATT ATC ATC AAT AAC AAC AAC AAC ATC ACA ATG ATG ATG GAA GAG GAG GAG GAA TTT TGG TGG TGG TGG GGT GGT GGT GGG GGT AAT GCA GCT GCC AAT TTT TTC TTT TTT TTT a. Apply the Jukes-Cantor model to find the number of real substitutions for all pairs of the sequences above. b. Assuming that what you found in a) is a measure of genetic distance, apply the Unweighted Pair-Group Method with Arithmetic mean (UPGMA) to build a phylogenetic tree for the proteins. Draw the resulting tree and label edge length (assuming scaled branch length). c. The sequences above come from a conserved BLOCKS motif in hexokinases. The species of origin are malaria parasite P. falciparum, blood fluke (Schistosoma mansoni), cow (Bos taurus), human (Homo sapiens), and common tobacco (Nicotiana tabacum) respectively. Given this information, do you think your tree in part a) is reasonable? ...
View Full Document

Ask a homework question - tutors are online