8/14/2019 Maris Stella High School GCE O Level

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Maris Stella High School Name: ___________________

GCE O Level Science Biology Class (Index No.): Sec 3___ ( )

TYS Answer Scheme Date: ________________

Unit 1: Cells Paper 4 Section A structured Qns

1a)

Part of cell In plant cellsonly

In animal andplant cells

cell membrane cell wall chloroplast cytoplasm nucleus Sap vacuole b) i) To transport oxygen around the body.

ii) The red blood cells cytoplasm has the red pigment haemoglobin that binds reversibly to oxygen.There is an absence of nucleus in the cell so that more haemoglobin can be packed into it to increase its

oxygen carrying capacity. The cell is flattened and biconcave in shape to increase the surface area to

volume ratio to increase diffusion rate of oxygen in and out of the cell.

2a)

Part of cell letter

cell membrane C

cell wall B

cytoplasm A

chloroplast E

nucleus Fvacuole D

b) 1. Presence of cell wall 2. Presence of chloroplast / large central vacuole

3a) 1. Presence of a mouth for feeding

2. Presence of a flagellum for movement

3. Presence of a sense receptor, the eye-spotb) Presence of chloroplast

c) The cellulose cell wall.

4ai) cytoplasm, cell surface/plasma membraneii) Absence of a large central vacuole and cellulose cell wall and the irregular shape of the cell indicates

that it is not a plant cell.

bi) Absence of nucleus in the red blood cell.

ii) 1.The red blood cells cytoplasm has the red pigment haemoglobin that binds reversibly to oxygen.

2. There is an absence of nucleus in the cell so that more haemoglobin can be packed into it to increaseits oxygen carrying capacity.

3. The flattened biconcave shape increases the surface area to volume ratio and allows the central region

to be