Overview
This lesson covers the structure and functions of specialised plant cells, including root hair cells, palisade cells, xylem, and phloem, and how their adaptations help plants survive.
Basic Structure of Plant Cells
- Plant cells have a nucleus, cell membrane, and cytoplasm like animal cells.
- Unique to plant cells: vacuole, chloroplasts, and cell wall.
Specialised Plant Cells
- Specialised plant cells include root hair cells, palisade cells, xylem cells, and phloem cells.
Root Hair Cells
- Found on the surface of roots and have tiny hair-like projections.
- Large surface area increases absorption of water and minerals from the soil.
- Lack chloroplasts because they are underground and do not absorb light.
Palisade Cells
- Located near the top of leaves to capture maximum sunlight.
- Packed with chloroplasts containing chlorophyll for photosynthesis.
- Primary site of photosynthesis, producing sugars for plant growth.
Xylem Cells
- Transport water from roots to leaves.
- Dead cells with ends broken down to form long tubes.
- Thick cell walls provide structural support, helping hold leaves and flowers upright.
Phloem Cells
- Transport sugary water (products of photosynthesis) from leaves to the rest of the plant.
- Alive and found near xylem in stems.
- Companion cells next to phloem contain many mitochondria to release energy needed for transport.
Key Terms & Definitions
- Chloroplast — Organelle in plant cells where photosynthesis occurs, containing chlorophyll.
- Chlorophyll — Green pigment in chloroplasts enabling photosynthesis.
- Mitochondria — Cell structures where respiration releases energy from glucose.
- Photosynthesis — Process in which plants use sunlight to convert carbon dioxide and water into glucose and oxygen.
- Xylem — Dead tube-like plant cells that transport water and support the plant.
- Phloem — Living cells that transport sugars around the plant.
- Root hair cell — Specialised cell with extensions to absorb water and minerals from soil.
Action Items / Next Steps
- Write paragraphs describing adaptations of root hair, palisade, xylem, and phloem cells.
- Use facts above to answer test questions or review quiz on specialised plant cells.