SPM Biology 2017

  1. Diagram 2.1 shows the structure of a fish. R, S and T are the fins of the fish. Diagram 2.2 shows the cross section across XY.

Rajah 2.1 menunjukkan struktur seekor ikan. R, S dan T adalah sirip-sirip pada ikan tersebut. Rajah 2.2 menunjukkan keratan rentas merentasi XY.

(a) (i) Name find R and T

Namakan sirip R dan Sirip T.

(ii) Explain why fin R is important to the fish when swimming.

Terangkan mengapa sirip R adalah penting bagi ikan semasa berenang.

Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

(b) explain how muscle P acts during the movement of the fish.

Terangkan bagaimana otot P bertindak semasa pergerakan ikan itu.


(c) Fin S is injured as shown in Diagram 2.3.

Sirip S tercedera seperti yang ditunjukkan dalam Rajah 2.3.

(i) Explain how does the injury affect the movement of the fish

Terangkan bagaimana kecederaan itu mempengaruhi pegerakan ikan tersebut.

(ii) The fish is able to adapt with the injury and survived. Describe how the fish overcomes the problem while swimming.

Ikan itu dapat menyesuaikan diri dengan kecedearaanya dan terus hidup. Jelaskan bagaimana ikan itu mengatasi masalah tersebut semasa berenang.

Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

(d) Hot water from a factory is released into the river. Diagram 2.4 shows the effect of temperature on the concentration of dissolved oxygen in the river. Explain how this situation causes the death of fish in the river.

Air panas daripada kilang dilepaskan ke dalam sungai, Rajah 2.4 menunjukkan kesan sukuk e atas kepekatan oksigen terlarut di dalam air sungai. Terangkan bagaimana situasi ini menyebabkan kematian ikan di dalam sungai.

Cher Questions Solution Bank Rumusan Jawapan SPM & IGCSE Questions Answers Solution

New Comer 0

Answer ( 1 )


    2. a) i)

    R: dorsal fin

    T: ventral fin

    ii) Fin R helps to resist yawing (moving sideways) and rolling (moving in the transverse plane) from occurring. This is to ensure that the fish has stable swimming.


    b)   Muscle P is myotome muscle. When myotome muscle on one side contracts, the other side relaxes. The fish body and tail would then bend towards the side in which the myotome is contracting.


    c) i) Fin S is the caudal fin, if it is injured there would be less thrust so the fish can’t swim quickly. Also it would be difficult for the fish to control its swimming direction.

    ii) Pelvic and pectoral fins act as brakes and rudders. In order for the fish to swim faster it would then have to minimize its usage of brakes or contract its myotome muscles more quickly to generate a larger forward force.  Whereas, to control the direction and to steer, it will then have to make more use of its rudder (pectoral fin).


    d) Whenever you have graph questions like this, it would be best to describe the relationship of the graph.

    As the temperature increases, the concentration of dissolved oxygen decreases. If hot water is continuously released from the factory, the temperature of the river water will keep increasing and the concentration of oxygen will keep decreasing. Without a sufficient supply of oxygen, this would result in fish death.

Leave an answer