Question 2
2. Study specimens H and J and answer questions 2(a) to 2(d).
(a) (i) Name the kingdom and Class of organisms from which specimen H could be obtained. [2 marks]
(ii) Name the specific location on the body of the organism from which specimen H could be obtained. [1 mark]
(iii) Name one example of organism from which specimen H could be obtained. [1 mark]
(b) (i) State six observable structural differences between specimens H and J. [6 mark]
(ii) State three observable structural similarities between specimens H and J [3 marks]
(c) State one function each of specimens H and J to the organisms that possess them [2 marks]
(d) Mention:
(i) three observable features that adapt specimen H to the function stated against it in 2(c);
[6 marks] (ii) two observable features that adapt specimen J to the function stated against it in 2(c). [4 marks]
Observation
In 2 (a) (i), many candidates tried in naming the Kingdom and Class of organisms from which specimen H could be obtained but candidates lost marks to wrong spellings of the names. Some even gave answers like ‘Animalian’, ‘vertebrate’ for the Kingdom and birds for the Class.
In 2 (a) (ii), majority of candidates were able to state the location of specimen H while some wrote feather, body, bird, which are wrong answers.
In 2 (a) (iii), some candidates just wrote ‘birds’ as an example of organism s from which specimen H could be obtained.
In 2 (b) (i), with so many observable differences, not many candidates scored good marks in this question. Many candidates, however, gave incorrect answers like one is an animal, the other is a plant, specimen H is soft and the other is hard, one regulates body temperature and the other is used to thatch house roofs. All the answers are not structural differences.
In 2 (b) (ii), not many candidates scored good marks in this question as many gave incorrect answers like both have flat surfaces, both are linear and elongated, both have shaft, vane, midrib, rachis as structural similarities.
In 2 (c), most candidates gave correct functions of the specimens H and J to the organism that possess them. Some however lost marks to incorrect spellings of technical terms.
In 2 (d), instead of giving the features that adapt the specimens to the functions, the candidates gave observable features only.
The expected answers are:
2. (a) (i) Kingdom and Class of organism from which specimen H/quill feather could be obtained
Kingdom
Animalia
Class
Aves
(ii) Location on the body of organism from which specimen H/quill feather could be obtained
Wing(s)/tail(s)
(iii) Example of organism from which specimen H/quill feather could be obtained
Pigeon/domestic fowl/cock/hen/dove/vulture/ostrich/gull/duck/any correctly named bird.
(b)(i)Differences between specimens H and J
Specimen H/quill feather |
Specimen J/Palm frond |
- Barbs present |
barbs are absent; |
-Vanes present |
vanes are absent; |
-Vein absent |
vein present; |
-Shaft/rachis present |
shaft/rachis absent; |
-Midrib absent |
midrib present; |
-Petiole absent |
petiole present; |
-Smaller in size |
larger in size; |
-Sharp margin absent |
sharp margin present; |
-Non-green in colour |
green in colour; |
-Barbules present |
petiole present; |
-Calamus present |
calamus absent; |
-Inferior/superior umbilicus present |
inferior/superior umbilicus absent; |
-Aftershaft present |
aftershaft absent; |
-Barbs are diagonal |
venation is parallel; |
-Blunt end |
tapers at the end/apex; |
-Short barb(s) |
long leaflet. |
(ii) Similarities between specimens H and J
- They both possess point of attachment;
- They both possess apex;
- They both have margin;
- Both have glossy surface.
(c) Functions of specimens H and J to the organisms that possess them Specimen H
- Insulation;
- Camouflage;
- Sexual/courtship display;
- Protection;
- Waterproof;
- Identification;
- Gives shape.
Specimen J
Photosynthesis/manufacture of food/transpiration/gaseous exchange.
(c) Observable features that adapt specimens H and J to their functions Specimen H
- Strong and firm; to beat against air/wind/protection/insulation;
- Hollow shaft/rachis/light weight; for buoyancy;
- Interlocking barbules/closely packed barbs; for upthrust;
- Colour; for camouflage/courtship display/identification;
- Glossy surface; for waterproof.
Specimen J
- Green colour; for photosynthesis;
- Veins; for conduct/transport of water/nutrients/food;
Glossy/waxy surface; makes it waterproof.