Bio Past Paper

Biology Animal Cell

Structure

Cell membrane

Cytoplasm

Nucleus (plural: nuclei)

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Mitochondrion (plural: mitochondria)

Vacuole

Features and main functions of cell structure

1. Cell membrane

Feature: Differentially permeable

Main function: Controls the movement of substances into and out of the cell

2. Cytoplasm

Feature: A jelly-like substance consisting of water, protein and other chemical substances

Main function: Holds organelles and is a place for chemical reactions to take place

3. Nucleus (plural: nuclei)

Feature: Exist in all animal cells except mature red blood cells

Round-shaped and bounded by the nuclear membrane

Main function: Contains genetic material DNA and controls all activities of the cell

4. Endoplasmic Reticulum (ER)

Feature: A network of interconnected membrane-bounded sacs connects cytoplasm and the nuclear membrane

Main function: Transports proteins synthesized at ribosome (Rough ER)

Smooth ER (without ribosome) is involved in the synthesis and transport of lipids

5. Mitochondrion (plural: mitochondria)

Feature: Rod-shaped and bounded by double membrane

Main Function: Releases energy through respiration

Respiration is not equal to breathing

Respiration= Oxygen + Glucose Carbon dioxide + Water + Energy

6. Vacuole

Feature: Bounded by a differentially permeable membrane

Small or no in most animal cells

Main function: Stores water and dissolved substances

Plant Cell

Structure

Cell wall

Cell membrane

Vacuole

Cytoplasm

Rough Endoplasmic Reticulum

Smooth Endoplasmic