1991 AL Biology paper 1 marking scheme

1991 AL Biology paper 1 marking scheme - 1991 AL Biology...

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1991 AL BIO PI MS – P.1 1991 AL Biology Paper I marking scheme Marks 1. (a) Hepaticae 1/2 (b) Chordata 1/2 (c) Coelenterata 1/2 (d) Sarcodina 1/2 (e) Gymnospermae/ pteridophyta 1/2 (f) Insecta 1/2 (3) (N. B. Accept taxonomic grouping at ANY level and common names.) 2. Role Deficiency symptom (a) calcium Required for development of stem and root apex; as calcium petite in plant cell wail Stunted growth of root and stem; flaccidity 1, 1 (b) nitrogen Required for formation of proteins, nucleic acids and porphyries, etc Stunted growth; chlorosis 1, 1 (4) 3. Bivalve - the movement of the cilia of the gill on each side of the body draws in a current of water via an halant siphon which leaves via an exhalent siphon - suspended food particles entangled by sticky mucus (produced by secretory cells on the gill) and swept (and sorted) by cilia towards the mouth OR Daphnia - thoracic limbs beating so as to draw a current of water towards the mouth - bristles filter off the food particles suspended in the feeding current - the food filtered is then. Sent towards the mouth by setae located at the base of each limb OR Other suitable examples e.g. some whales (N.B. Deduct 1 mark for failure to name the filter feeder.) In Q.3, Paramecium was all too often considered as a filter feeder, which technically it cannot be as a single celled organism, because it has no true mouth and its oral groove cilia, (often miss pelt as cilia), are not selective in dealing with food material. 1 1 1 1 1 1 1
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