BIOLOGY PAPER 231/2 K.C.S.E 1995 PRACTICAL MARKING SCHEME

BIOLOGY PAPER 231/2 K.C.S.E 1995

PRACTICAL MARKING SCHEME

1. Confidential requirement: Specimen K – 5 Rastrineobolla argenti

(Omena in Luo)

You are provided with a specimen labelled K. With the help of a hand lens examine the specimen.

a) (i) State the phylum to which the specimen belongs: Chordata;

(ii) Using the observable features only, name the class to which the specimen belongs:

Pisces.

(iii) Give your answer in (a) (ii) above:

Lateral line / operculum / gill cover / gills, fins

Accept fish, Osteichthyes / bony fish etc.

b) Using the observable features only, state how the animal is adapted to living in its habitat.

• Streamlined body for easy movement / minimize friction (owwte)
• Presence of fins for swimming / balance
• Presence of gills for breathing in water / gaseous exchange / operculum / gill cover to allow water to pass out
• Presence of lateral line helps detect vibration / movements in water waves / disturbance in water

c) Cut three of specimen K into tiny pieces. Place the pieces into a boiling tube. Add 5 ml of water. Boil for five minutes. Decant the extract into a clean test tube.

Using the reagents provided, identify the food substances in the extract. Record the food substances being tested for, observations, and conclusions in the table below.

2. Confidential requirement: Specimen M – Freshly picked and intact mature flower obtained Solanum incanum or Lycopersicon.

You are provided with a specimen labeled M. Make a longitudinal section through the flower.

a) (i) Draw and label the longitudinal section of the flower.

(ii) State the magnification of your drawing:

X1 – X10 (with or without the x)

b) (i) Name the agent of pollination of the flower:

Insects – (Reg – animal alone)

(ii) State two ways in which the flower is adapted for pollination by the agent named in b(i) above.

• Brightly coloured to attract insects.
• Stigma is below anther to avoid self-pollination.
• Smell/scent to attract insects.

3. Confidential requirement: Specimen N – Freshly killed soldier termite.

Specimen P – Freshly killed weevil, Specimen Q – Freshly killed maggot of a housefly.

b) With a reason in each case, state the type of locomotion each animal exhibits.

c) (i) Adult / imago;

(ii) Larva Rej; maggot