Plant Biology: Photosynthesis and Tissues

Study Notes

Chloroplasts in cells enable photosynthesis, primarily occurring in leaves.
Ground tissue functions include storage of food and water in stems and roots.
Provides structural protection and contributes to rigidity in non-woody plants through turgor pressure.

Comprises vessels and tracheids, crucial for water and mineral transport.
Xylem vessels are narrow, increasing capillary action; heavily lignified, and dead at maturity.
Lignin provides structural strength against water tension.
Tracheids are thickened with lignin, waterproof, and help in lateral water movement via pits.

Contains sieve tube cells that lack a nucleus and stores food for distribution.
Transports food and nutrients vertically throughout the plant, aiding vegetative reproduction in plants like strawberries.

Composed of a petiole (stalk) and a flattened lamina (blade), with vascular bundles forming visible veins.
In monocots, leaf veins run parallel; in dicots, they are branched.
Primary role is photosynthesis, maximizing light capture with a large surface area.
Acts in food storage (e.g., cabbage, onion) and waste excretion.

Flowers serve as the reproductive organs of plants, attracting pollinators with their color and scent.
Pollination can occur through wind for smaller, less colorful flowers.

Dermal tissue acts as a protective outer layer; in older plants, cork provides insulation.
Stomata in leaves manage gas exchange and transpiration; lenticels serve a similar purpose in woody stems.
Ground tissue also supports photosynthesis through spongy and palisade mesophyll layers in leaves.

Seeds consist of an embryo, testa (seed coat), cotyledons, a plumule, a radicle, and sometimes endosperm.
Seeds germinate under optimal conditions of water, oxygen, and temperature.

Tap roots develop from the radical; lateral roots branch out for anchorage and nutrient uptake (e.g., carrots).
Fibrous adventitious roots can form where the radical does not persist (e.g., grasses).
Root growth occurs at the apical meristem, producing a protective root cap.
The zone of elongation pushes roots forward, while root hairs increase surface area for water and mineral absorption.
Vascular tissues (xylem and phloem) differentiate near the core of the root.