1 (a) Diagram 1.1 shows the process of colonisation and succession in a habitat.Rajah 1.1 menunjukkan proses pengkolonian dan penyesaran dalam suatu habitat.

Diagram 1.1What is meant by “colonisation and succession in a habitat”?Based on Diagram 1.1, explain how colonisation and succession bring about the formation of the primary forest in a habitat.Apakah yang dimaksudkan dengan “pengkolonian dan penyesaran dalam suatu habitat”?Berdasarkan Rajah 1.1, terangkan bagaimana pengkolonian dan penyesaran membawa kepada pembentukan hutan primer dalam suatu habitat. [10 marks]Colonisation is a process whereby a species colonise/ inhabitat and survives in a newly formed area/ habitat. [1]

Succession is a process whereby one species of organism changes the environment/ habitat which result in the species been replaced by other species/ successor which is more adaptable to the habitat. [1]Colonisation and succession in a pond

Activity of pioneer species/ submerged plants causes changes to the habitat. The remains of the plant decayed matter sunk/ deposited to the pond’s bed causing the pond to become shallow beside adding humus to the water and soil. This condition is more favourable for the growth of floating plants which replaced the

pioneer species. Floating plants cover the surface of the water preventing light from penetrating the water

causing rate of photosynthesis of plants in the pond. More plants dies and sink to the bottom of the pond causing the pond to become more shallower. Emergent/ amphibian plants gradually replace the floating plants and causes further changes to the pond making it unfavourable for amphibian plants to grow. Finally, amphibian plants are replaced by terrestrial plants which formed the climax

community. [8]

(b) Diagram 1.2 shows an ecosystem in Malaysia.

Rajah 1.2 menunjukkan suatu ekosistem di Malaysia.

Diagram 1.2Based on Diagram 1.2, discuss why the ecosystem has to be maintained.Berdasarkan Rajah 1.2, bincangkan kenapa ekosistem ini perlu dikekalkan.[10 marks]Importance of maintaining a balanced ecosystem

It is a balanced ecosystem which allows maximum interaction among biotic factors and between biotic and abiotic factors. [1] to ensure conservation of biodiversity/ preservation and conservation of flora and fauna to prevent extinction of species A balanced ecosystem maintains major sources of human food like ulam, ferns and meats

and medicinal resource like herbs. [1] to sustain food web/ chain in ecosystem to prevent disruption of natural water and carbon cycle provide water catchment area. Preserve natural sources for recreational activities promoting healthy life style. Imbalance ecosystem causes the loss of plants and animals in the ecosystem.[1] Causes reduction in the food resources/ food web Causes natural disaster, soil erosion, land slide and flash flood. Causes extinction of a few animal/ plant which might be useful in the future

[SPM 2007: P2 Q9]

2 (a) (i) After absorption of nutrients in the small intestine, the undigested substances in the colon result in the formation of faeces. Explain the formation of faeces in a human.

Selepas penyerapan nutrien dalam usus kecil, bahan-bahan yang tidak tercerna dalam usus besar akan membentuk tinja. Terangkan pembentukan tinja dalam manusia.

[4 marks] Contents in small intestine that are not absorbed/ undigested food enter the colon The intestinal content consists of a mixture of water/ water and fibers/dead

cells/pigments The contents move slowly along the colon by peristalsis Water is reabsorbed from the contents in the colon to form semi-solid waste/ faeces(ii) Malnutrition is a condition due to taking an unbalanced diet in which certain nutrients

are lacking, in excess or in the wrong proportions.Explain the effect on a child who is given insufficient amounts of any two nutrients of food for a long period of time. Malnutrisi adalah keadaan yang timbul akibat pengambilan gizi yang tidak seimbang di mana ada nutrien tertentu yang kurang, berlebihan atau dalam nisbah yang salah.Terangkan kesan kepada seorang kanak-kanak yang diberi mana-mana dua nutrien makanan dalam amaun yang tidak mencukupi untuk satu tempoh masa yang panjang.

[6 marks]Protein(F + S + C)

A child who is deficient in protein may suffer from kwashiorkor/maramus Protein is needed for normal growth// tissue repaired Lack of protein causes growth of the child to be stunted/stunted growth

Vitamin A A child who is deficient in vitamin A may suffer from night blindness Vitamin A is needed to ensure healthy rod cells in the retina Lack of vitamin A reduced ability to see in dim light

Vitamin D A child who is efficient in vitamin D may suffer from rickets Vitamin D is needed for healthy development of bones Lack of vitamin D causes bones to become soft and grow irregularly

Vitamin C A child who is deficient in vitamin C may suffer from scurvy Vitamin C is needed or healthy gum and skin Lack of vitamin C causes swollen and bleeding gum

Dietary fibre A child who is deficient in roughage may suffer from constipation Roughage is needed to stimulate peristalsis/ increase the volume of food/enhance water reabsorption in faeces Lack of roughage causes constipation/ difficulty in egesting

faeces/defaecation//haemorroids/piles//colon cancerCalcium

A child who is deficient in calcium may suffer from osteoporosis Calcium is needed to form bones and teeth Lack of calcium causes the mass of bones to decreases/ bones become porous and light

Iodine A child who is deficient in iodine may suffer from goiter Iodine is needed to produce thyroxine Lack of iodine causes mental retardation/infertility

Carbohydrate A child who is deficient in carbohydrate may suffer from maramus

Carbohydrate is needed for energy production/ activity of body Lack of carbohydrate causes weight loss/tiredness

(b) Table 2 shows the food intake by a boy aged 15 years in his daily menu. The daily energy requirement for him is 12 500 kJ.Jadual 2 menunjukkan makanan yang diambil oleh seorang budak lelaki berumur 15 tahun dalam menu hariannya. Keperluan tenaga budak itu ialah 12500kJ.

Types of foodJenis makanan

Quantity taken/ gKuantiti yang diambil/g

Energy / kJ per 100gTenaga/ kJ per 100g

Rice 400 1600

Potato chips 500 1000

Chicken curry 300 300

Boiled egg 150 630

Butter 50 3000

Milk 280 300

Sausage 300 500

Sardine 150 900

Table 2Jadual 2

(i) Based on Table 2, state the value of energy contained in this daily food intake.Does the food intake satisfy his daily energy requirement? Berdasarkan Jadual 2, nyatakan nilai tenaga yang terkandung dalam pemakanan hariannya. Adakah pengambilan makanan itu memenuhi keperluan tenaga hariannya?

[2 marks]F1 - The energy produced from the food taken daily is 18435 kJF2 - The energy produced from the food taken daily is more than the daily energy requirement

(ii) This boy takes this menu continuously for a long time. Explain the consequences to his health.Budak lelaki ini mengambil menu ini secara berterusan dalam jangka masa yang panjang. Terangkan akibatnya terhadap kesihatan budak ini. [8 marks]

The menu is unbalanced diet becauseF1 - Does not contain the 7 classes of food in the appropriate ratio//C1 - Leads to malnutrition//F2 - Does not contain sufficient dietary fibre/roughage//C2 - Leads to constipation//F3 - Contains only certain vitamin//C3 - Causes deficiency diseasesF4 - Contain high fat//C4 - Causes obesity/cardiovascular diseases//F5 - Contain high protein//C5 - Causes gout/increase in an acid uric level in blood/kidney/liver failureF6 - Contain high carbohydrate//C6 - Causes obesity/diabetes mellitus/high blood sugar level

[SPM 2008: P2 Q8]