Question 4
LIST OF SPECIMENS
Specimen A - Fresh/wet preserved mosquito larva in a Petri dish containing water.
Specimen B - Fresh/wet preserved maggot in a Petri dish containing water.
Specimen C - Gill of fish (freshly procured) in a Petri dish containing water.
Specimen D - Lung of a small mammal (freshly preserved).
Specimen E - Dicotyledonous leaf (freshly plucked).
Specimen F - Membranous wing of a Cockroach.
Specimen K - Flower of Pride f Barbados or Caesalpinia.
Specimen L - Mature Elephant grass or Guinea grass.
Specimen M - Flower of Hibiscus plant.
Study specimens K and L and answer questions 4(a) to 4(f).
(a)(i) Name the floral parts of specimen K. [4 marks]
(ii) Indicate the number of floral parts in each whorl of specimen K.[4 marks]
(b)(i) Name the sex of specimen K. [1 mark]
(ii) Give one reason for the answer in 4(b)(i) [1 mark]
(c)(i) What is the symmetry of specimen K? [1 mark]
(ii) Give one reason for the answer in 4(c)(i) [1 mark]
(d) Name one pollinating agent of each of specimens K and L. [2 marks]
(e) State four observable differences between specimens K and L [4 marks]
(f) Make a drawing 8 cm – 10 cm long of the longitudinal section of specimen K and label fully. [12 marks]
Observation
In 4 (a) (i), many candidates could name the floral parts of specimen K, but lost marks to poor spellings of the parts, especially androecium and gynoecium.
In 4 (a) (ii), some of the candidates could answer this question while some could not.
In 4 (b) (i) and (ii), majority of the candidates could give the sex of specimen K and state the reason for the answer, although some candidates lost marks to poor spelling of hermaphrodite.
In 4 (c) (i) and (ii), some candidates lost marks to poor spelling of the answer. Many candidates could not also state the reason for the answer.
In 4 (d), many candidates lost marks to writing ‘insect’ instead of naming the exact insect or the organism.
In 4 (e), many candidates found it difficult to write the structural differences between specimens K and L.
In 4 (f), some candidates found it difficult to make the diagram with the specification given, some also lost almost all the marks on quality and details.
The expected answers are:
(a) (i) Floral parts of Specimen K/Pride of Barbados flower
- Sepals/calyx;
- Petals/corolla;
- Stamen/androecium;
- Pistil/gynoecium.
(ii) Number of Floral parts of Specimen K/Pride of Barbados flower
Sepals/calyx: 5/4+1
Petals/corolla: 5/4+1
Stamen/androecium: 10
Pistil/gynoecium: 1
(b) (i) Sex of Specimen K/Pride of Barbados flower
Hermaphrodite/bisexual
(ii) Reason for the answer in (b) (i)
It has both stamen and pistil/male and female organs/androecium and gynoecium.
Note: stamen and pistil must be together to score
(c) (i) Symmetry of Specimen K/Pride of Barbados flower
Bilateral/bilaterally symmetrical.
(ii) Reason for the answer in (c) (i)
It can be cut into two equal halves along only one plane.
(d) Name of pollinating agent of specimens K/Pride of Barbados flower and L/Elephant grass
Specimen K/Pride of Barbados: Butterfly/Bees
Specimen L/Elephant grass: Wind
(e) Observable structural differences between specimens K and L
Specimen K/Pride of Barbados/flower |
Specimen L/Elephant grass |
|
flowers are inconspicuous/small; |
|
dull coloured flowers/green; |
|
not scented flowers; |
|
small/light pollen grains; |
|
stigma is not sticky. |
Note: No penalty if no table
(e) Drawing/diagram of the longitudinal section of Specimen K/Pride of Barbados flower
Title (TL)
Quality (Q)
Size (SZ) (8cm – 10cm long)
Clarity of lines (CL)
Neatness of labels (NL)
Magnification (MG) (x½ to x1)
Details (D)
Standard petal shown (SP)
At least three filaments shown (FS)
Cut surfaces shown with double lines (CS)
At least four ovules shown in ovary marginally arranged (OS)
Label (L)
Petal, sepal, stigma, style, filament, anther, standard petal, receptacle/thalamus, pedicel/flower stalk.