Summative Practice Chapter 9 – Question 3, 4 & 5 (Form 5 Biology Textbook Exercise and Answer)

Question 3:
A study has been carried out to estimate the population size of fish in a pond. The steps of the study are as below:

• Fish are captured, marked and released back into the pond.
• After a week, fish are recaptured and counted.
• The number of marked fish is recorded.

(a) What is the most suitable substance to be used as a marker?

(b) State the formula to estimate the population size of the fish.

(c) The accuracy of this technique is dependent on assumptions. Give two assumptions about the fish population.

(a) Waterproof paint


(c)(i) There is no migration in and out of the studied fish species because the pond is a closed habitat.

(c)(ii) There is no dead or hatches of fish fry during the study.

Question 4:
Assume that you are an operational officer in a company which produces charcoal using mangrove trees. The management of the company that you are working for wants to establish another factory. You have been asked to suggest an area to build the factory. Draw an area plan and list the advantages of the selected location.

Area: Jeram, Kuala Selangor
• There are many raw mangrove woods.
• Labours can be easily gained from the villagers of the surrounding villages.
• There are many empty sites to build factories.
• Good transport system.
• Nearby to the main towns in which the charcoal will be marketed.

Question 5:
Mrs. Haniza is an ecology lecturer. She wants to take her students to do a field study in a mangrove forest. The purpose of the field study is to study the aeration and support systems of mangrove trees growing in the muddy and silted beach area. She estimates that they will take two days to complete the field study. However, Mrs Roziana who is another lecturer in ecology has estimated that the field research can be done within one day.

(a) In your opinion, whose estimation is more appropriate?

(b) Suggest suitable activities that can be done during the field study.

The study is about the aeration and support systems of the mangrove trees.
Involve supervision towards pneumatophore roots, prop roots and buttress roots.
High tide and low tide happen twice a day at the study site.
Some part of the roots are submerged with seawater during high tide.
Needs longer time as estimated by Mrs Haniza.

Observing and drawing plants species in different zones
Estimating the population of organisms
Listing down the biotic and abiotic components
Constructing food chains and food webs
Taking photographs of mangrove species in different zones

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