Biology · 2005 · November · Paper 3 · HL · Question paper

8805-6003 20 pages N05/4/BIOLO/HP3/ENG/TZ0/XX+ Friday 11 November 2005 (morning) BIOLOGY HIGHER LEVEL PAPER 3  IB DIPLOMA PROGRAMME PROGRAMME DU DIPLÔME DU BI PROGRAMA DEL DIPLOMA DEL BI INSTRUCTIONS TO CANDIDATES • Write your session number in the boxes above. • Do not open this examination paper until instructed to do so. • Answer all of the questions from two of the Options in the spaces provided. You may continue your answers on answer sheets. Write your session number on each answer sheet, and attach them to this examination paper and your cover sheet using the tag provided. • At the end of the examination, indicate the letters of the Options answered in the candidate box on your cover sheet and indicate the number of answer sheets used in the appropriate box on your cover sheet. 1 hour 15 minutes [Personal identifier removed] [Personal identifier removed] 0120 8805-6003 – 2 – N05/4/BIOLO/HP3/ENG/TZ0/XX+ Option D — Evolution D1. Researchers often use short pieces of DNA called Alu sequences to study relationships within populations and between species. The function of these sequences is not known. However, they have the ability to copy themselves at random and insert into other parts of the genome, increasing the DNA fragment size. Alu sequences have inserted into the genome of primates throughout their evolution. One particular group of sequences (Ye) began inserting into the genome relatively early in the evolution of Hominidae and continues to insert itself at low rates. The gel electrophoresis samples below were used to determine the phylogenetic origin of individual Ye5 sequences in primates. The larger DNA fragment in each case contains the Ye5 insert and the smaller fragments are the same region of DNA but without the insert. The green monkey and the owl monkey diverged from the Hominidae approximately 25 million years ago. Key: bp = base pairs Hominidae 100 bp markers Human Bonobo Chimpanzee Gorilla Orangutan Siamang Green Monkey Owl Monkey A B C D E 500 bp 185 bp 840 bp 500 bp 507 bp 183 bp 485 bp 170 bp 461 bp 126 bp (contains Ye5AH110 insert) (contains Ye5AH31 insert) (contains Ye5AH140 insert) (contains Ye5AH29 insert) (contains