Answers to Hands on Pg 87-89

8.1 Intraspecific competition and interspecific competition

Aim : To sudy the intraspecific competition and interspecific competition in plants

Hypothesis : The greater the intraspecific and interspecific competition, the shorter the plant.

a) MV : Type of seedlings

b) RV : Heights of seedlings

c) FV : Amount and type of soil//amount of water//light intensity//amount of seedling//distance between seedlings

Results:

Seedling tray	Height of plants (cm)
	1	2	3	4	5	6	7	8	9	10	Mean
A (Paddy)	25.1	24.2	26.3	24.0	23.8	25.4	25.8	26.1	25.7	26.9	25.33
B (Maize)	30.8	32.3	34.1	33.4	34.0	32.8	32.6	33.0	34.1	32.1	32.92
C (Paddy)	20.2	20.3	19.8	19.1	18.2	16.1	18.4	16.8	17.0	19.4	18.52
C (Maize)	38.4	40.1	40.5	38.8	38.8	39.4	41.2	40.8	41.1	39.7	39.88

**Please draw bar chart**

Discussion

1. A : Intraspecific competition

B : Intraspecific competition

C : Interspecific competition

2. The paddy plants in A are taller than those in C because interspecific competition in C causes the paddy plants to lose to maize plants. The shorter paddy plants do not absorb enough sunlight and their root systems are not extensive enough to absorb enough water.

3. Dry mass

Conclusion

Hypothesis is accepted. The greater the intraspecific and interspecific competition, the shorter the plant.