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KAKAMEGA CENTRAL JOINT EVALUATION TEST
BIOLOGY 231/3 PRACTICAL MARKING SCHEME
JULY/AUGUST 2011
1.(a)
Substance
Starch;
Procedure
- Add a few drops of iodine into (a little)
substance P
- To (a little amount) of substance P, add a
few drops of sodium Hydroxide, then add
1% copper sulphate shake to mix
thoroughly
- To (a little amount) of substance P, add a
few drops of Hydrochloric acid, then warm. Cool it and add a few drops of Sodium
Hydrogen carbonateuntil fizzling stops. Add
equal amount of benedicts solution; boil /heat;
Protein;
Non-reducing
sugar;
Observation
Brown colour/ colour
of iodine/ yellow;
Purple colour;
Conclusion
Starch absent;
Colour change from
Blue to green to
yellow to orange;
Non-reducing
present;
Protein present;
N/B – Reject the observation and conclusion if the procedure is wrong and conclusion if observation is
wrong. (b) Source of energy
- Form enzymes
- Form hormones
- For hair/nails
- Form protoplasm/repair worn out tissue/body building
- Form (structure of) cell membrane
- For muscle fibrils myofibrils / Actin/myosin
2. (a)
Function
– filament
Attachment of/expose the anthers
X
– sepals /calyx
Protect the flower parts during bloom/during bud development
Y
(b) Gamopetalous /fused petals partially; and polypetatous/free petals partially;
(c) Sepals are free/polysepalous;
(d) Hypogynous ovary/superior ovary;
(e) (i) Monocotyledonae
(ii) – Stamens/Anther/filaments are three;
- Petals /sepals are six/multiple of three;
3. (a)
K
Thoracic vertebra;
L
Axis;
M
Atlas ;
(b) (i) Neck
region/cervical region;
(ii) S- Tubercular facet;
Reasons
- Long neural spine;
- Short transverse processes;
- Extra (more) facets/capitular demi-facet
- Arbecular facets present; (any one)
- Odontoid process (peg);
- Transverse processes are downwards and
face backwards
- Reduced /short neural spine (any one)
Reduced neural spine;
Vertebreterial canals present;
Flat transverse processes;
Centrum is lacking;Large
facets/prezygophyses; (any one)
t – Capitular demi-facet;
(c)
t
U
V
– Articulate with capitulum of the rib ;
– fits into the (bottom half of the ) neural canal of the atlas to allow sideways movement of the head;
Allows passage of blood vessels /nerves to and from the spinal cord;
W
Articulates with occipital condyles of the skull;
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