how dose each part of the external leaf is adapted to carry of photosynthesis?
Each part of the external leaf is adapted to carry out photosynthesis in the following ways:
1. Epidermis: The epidermis is a thin, transparent layer of cells that covers the upper and lower surfaces of the leaf. It protects the inner tissues of the leaf and allows light to enter for photosynthesis to occur.
2. Cuticle: The cuticle is a waxy layer that covers the epidermis and helps prevent water loss from the leaf. It also helps protect the leaf from harmful UV radiation and pathogens.
3. Stomata: Stomata are small openings in the epidermis that allow gases to enter and exit the leaf. Carbon dioxide enters through the stomata for photosynthesis, and oxygen and water vapor exit the leaf through these openings.
4. Palisade mesophyll: The palisade mesophyll is a layer of tightly packed, column-shaped cells located just below the upper epidermis. These cells contain a large number of chloroplasts, which are the sites of photosynthesis.
5. Spongy mesophyll: The spongy mesophyll is a loosely packed layer of cells located below the palisade mesophyll. These cells have air spaces between them that allow for the exchange of gases during photosynthesis.
6. Chloroplasts: Chloroplasts are specialized organelles within plant cells that contain chlorophyll, the pigment responsible for capturing light energy for photosynthesis. Chloroplasts are abundant in the palisade mesophyll cells, where most of the photosynthetic reactions take place.
7. Veins: The veins of the leaf transport water and nutrients to the cells involved in photosynthesis. They also transport sugars produced during photosynthesis to other parts of the plant for storage and use.
Overall, the external leaf is adapted to maximize sunlight absorption, gas exchange, and water and nutrient uptake to ensure efficient photosynthesis and the production of glucose for the plant's energy needs.