2018 WAEC Biology Practical Answers Expo/Runs - specimens

2018 WAEC Biology Practical Answers Expo/Runs - specimens

Below are the specimens and questions for 2018 waec biology practical . study them carefully as these will certainly come out in your actual exam. compiled by bmasterz

2018 WAEC Biology Practical Answers Expo/Runs

Below are WAEC Biology Practical Answers 2018

Question 1

LIST OF SPECIMENS PROVIDED

SPECIMEN  A:  GARDEN EGG

SPECIMEN B:   TRIDAX FRUIT

SPECIMEN C:   GRAIN WEEVIL

SPECIMEN D:    TICK

SPECIMEN E:     RAT/GUINEA PIG

SPECIMEN J:      TILAPIA FISH (WET PRESERVED)

SPECIMEN K:      TOAD (WET PRESERVED)

SPEICMEN L:       LIZARD (WET OR DRY PRESERVED).

Question 1

Study carefully specimens A and B and use them to answer questions

1(a) to 1(c).

(i)  Name the types of fruit in specimens A and B with reasons                        [ 4 marks ]

(ii)   Make a drawing, 8 – 10 cm long of the lateral view of

       Specimen B and label fully.                                                                              [ 10 marks ]

  Describe the modes of dispersal of specimens A and B.                                     [ 6 marks ]

   In a tabular form, state five differences between specimens A and B             [ 5 marks ]

OBSERVATION: This was the less popular question in this  section.  Most candidates could not correctly name the type of fruits in specimens A and B.  Some wrote that specimen A is a succulent, true fruit While specimen B is a dry indehiscent fruit.  Some candidates who got the correct answer     missed the mark because of wrong spellings.  The expected answers were:

Specimen A/Garden egg is a Berry

Specimen B/Tridax fruit is a Cypsela.

They could not state the reasons correctly.

Expected answers include:

A/Berry- it has a fleshy  pericarp with many seeds embedded in it.

B/Cypsela - fruit bears a hairy calyx/hairy pappus/parachute;

                 - dry single seeded fruit.

 Most candidates performed fairly in the diagram of specimen B/Tridax but did not show the rachis of the pappus with double lines and did not conform to size specifications.  This led to them scoring low marks. Only few candidates could correctly state the modes of dispersal of specimens A and B and correctly state five differences between the specimens.   Expected answers include:

b)(i)      Modes of dispersal

            A/Garden Egg

          The fruit is soft and edible;

           Man and animals eat the soft pericarp;

           The seeds are spat out /egested /scattered.         

            B/ Tridax

            > Feathery papus traps air;

            > This increases the surface area of the fruit with respect to the volume;

            > So reduces the weight of the fruit;

            > To be blown and dispersed by the wind;

            > Tough (dry) pericarp protect the seed embryo.     

                                         Differences between specimens A and B

            Specimen A(Garden Egg)                              Specimen B(Tridax Fruit)

                Fleshy pericarp                                        Dry pericarp;

               Smooth epicarp/fruitwall                          Hairy epicarp;

               No pappus                                                Pappus present;

              Calyx beneath fruit                                   Calyx (pappus) on top of fruit;

              Calyx present                                            Calyx modified into pappus;

              Large fruit                                                 Small fruit;

              Heavy fruit                                                Light (in weight) fruit;

              Green/white/yellow in colour                     Brown in colour.

Question 2

Study carefully specimens E and F and use them  to answer 2(a) to 2(d)

(i)  What class of organisms do specimens E and F belong to?                           (1 mark)

(ii)  State three similarities between specimens E and F                                     (3 marks )

(Iii)  In a tabular form, state three differences between specimens E and F   (3 marks )

  State two  ways each in which:

(i)Specimen E;

(ii)  Specimen F are of economic importance                                                         (4 marks )

OBSERVATION: This was the most popular in this section and a lot of candidates scored high marks in this question. Most candidates  could correctly state the class to which specimens E/cockroach and F/soldier termite belong namely, class insect but a good number of candidates lost the score due to spelling errors e.g. class insecter instead of insect.  The candidates could properly state similarities between the specimens, their economic importance; their habitats and their adaptations against predators.  They however performed poorly in outlining the differences between specimens E and F. Expected answers include:

Specimen E/Cockroach                               Specimen F/Solder Termite.

        Small head;                                                 Large head

        Wings present;                                            Wings absent

        Has compound eye/has sigh;                      No eye/blind/no sight

        Dark brown colour                                     Light brown colour

        Small mandibles present.                           Large mandibles present

    A few candidates made good drawings of specimen E/cockroach and scored good marks but a large number of candidates mad poor diagrams with blunt pencils leading to wooly and broken lines.  Some candidates failed to remove the wings of the cockroach and so lost marks.  Many candidates did not give titles to their diagrams, did not state the magnification and had guidelines of labels crossing each other.  In addition a lot of candidates loss marks due to poor spelling of labels.

Expected answers include:

Title(T) Drawing of dorsal view of specimen E (Cockroach) Quality (Q)

Size: 8 – 10cm (Sz)

Clarity of lines (CL)  (lines not wooly x ½ ; not broken/dotted x ½ )

Neatness of labels (NL) (ruled guidelines x ½ ; horizontal labels x ½ )

Magnification (mg) x 1.5 – 2.5;

Details (D)

At least five abdominal segments shown (AS)/spiracles shown (SS)

Label(L)

Head, antenna,  compound eye. Thoracic segment/prothorax, mesothorax and metathorax, spiracle, abdominal segment, leg (jointed) circus.

Question 3

Carefully study specimens J and K and answer questions 4(a) to 4(d).

 Name the type of refuse in specimens:

(i)  J;

(ii) K.                                                                                                                 (2 marks )

 (i) List three animal vectors of disease causing organisms that breed on each of specimens J  and K                                                                                                   (6 marks)

(ii) Name four diseases each caused by the animal vectors associated with each of specimens J and K                                       (8marks )

 Name one method of disposal of each of specimens J and K in:

(i) Rural areas;

(ii) Urban areas.                                                                                             (4 marks )

(i)     State four effects of improper disposal of specimen K                             (4 marks )

(ii)     In a tabular form, state five differences between specimen J and K                 (5 marks )

(iii)      Outline one way in which specimen J is of importance to farmers.                  (1 mark )

OBSERVATION: Many candidates performed fairly well on this question and scored fair marks.  Most candidates could state the type of refuse namely J- dry refuse/waste and K wet refuse/waste/sewage/  Most candidates could correctly state animal vectors that breed on specimens J and K and the diseases associated with the specimens but lost marks due to spelling errors.  Expected answers include:

Animal vectors that breed on specimen J

1. Rat;
2. Housefly;
3. cockroach.

Animal vectors that breed on specimen K

1. Housefly;
2. Black fly;
3. Female Aedes/Anopheles mosquito/mosquito;

Disease associated with specimen J

Typhoid; plague; dysemtery; cholera; diaorrhea.

Diseases associated with specimen K