Biology · 2001 · November · Paper 2 · HL · Markscheme

MARKSCHEME November 2001 BIOLOGY Higher Level Paper 2 14 pages N01/410/H(2)M INTERNATIONAL BACCALAUREATE BACCALAURÉAT INTERNATIONAL BACHILLERATO INTERNACIONAL SECTION A [3 max] 1. (a) the pheasant uses more power / energy than the duck (to fly at all speeds); the overall shape of the curves is the same; the most efficient flying velocity is the same for both birds / slightly higher for pheasants; the velocity that uses the least power for flight is lower for the duck than the pheasant; (Reject the duck is more efficient at using energy to fly) [1 max ] (b) the mass of the duck is lower than the mass of the pheasant; more energy / power needed for greater mass; [3] duck energy used divided by metres travelled; 2.6 – 2.8 at V;1Jm − 3.0 – 4.0 at least power velocity;1Jm − OR(c) pheasant energy used divided by metres travelled; (need not be stated and can be accepted if this is shown in the working) 3.8 – 4.0 at V; 1Jm − 5.3 – 6.3 at least power velocity;1Jm − (Penalise lack of units once only. Accept J s ms for the units.)−1 −1 Accept for [1] only answers in which the candidate calculates velocity divided by power for V and for least power. Also accept for [1] only answers in which the candidate shows that from V to least power, velocity is reduced proportionately more than power. [1](d) 26 (flaps); [3 max] (e) vigorous contractions during take off and landing, less vigorous contractions during fast flight; decreasingly vigorous contractions during take off and fast flight / increasingly during landing; fewer contractions per unit time in (later stages) of fast flight than other phases; most vigorous contractions during landing; (Accept active / activity or electrical activity throughout instead of contractions) [1 ](f) TB is used (mainly) for landing ; [1](g) the upstroke of the wing; [2] (h) similar frequency to the SB muscles / same number of contractions; the peaks of activity would be out of phase / alternate with those of the SB and TB; – 6 – N01/410/H(2)M