Biology · 2001 · November · Paper 3 · HL · Markscheme

MARKSCHEME November 2001 BIOLOGY Higher Level Paper 3 14 pages N01/410/H(3)M INTERNATIONAL BACCALAUREATE BACCALAURÉAT INTERNATIONAL BACHILLERATO INTERNACIONAL Option D – Evolution [1 max] D1. (a) fewer males per females; small population on island (may lead to ) inbreeding / (deleterious) alleles appearing that decrease fertility; shortage of food / overcrowding; better breeding sites; (Do not accept more females) [1 ](b) (i) mainland population has more heterozygotes as more genes polymorphic; [2 max] (ii) variation needed to respond to environmental change; island population has less variation so more vulnerable to change; polymorphism allows better chance that some animals could adapt / survive; island population cannot migrate / escape; [2 max] (c) Hardy-Weinberg equilibrium occurs if allele frequency remains constant over generations / a population is not in Hardy-Weinberg equilibrium if allele frequencies have changed over generations; founder population is probably not at Hardy-Weinberg equilibrium; island population is probably sm all and not likely to be in equilibrium / so genetic drift a factor to move from Hardy-Weinberg equilibrium; could be at Hardy-Weinberg equilibrium because allele frequencies may not have changed / alleles are fixed; [2 max] D2. (a) (Kingdom) Animalia (Phylum) Chordata (Sub-phylum) Vertebrata (Class) Mammalia (Order) Primata (Family) Hominidae (Genus) Homo (Species) sapiens (4 to 6 correct [1], 7 to 8 correct [2]. Award [1] if 7 to 8 correct, but incorrect order.) [1 ] [1] (b) (i) grasp / manipulation / climbing; (ii) stereo / binocular vision / depth perception; – 6 – N01/410/H(3)M