Discovery Science: Earth Biology – Plants and fungi – Anatomy of Higher Plants

Earth Science: Biology – Morphology and Physiology

Almost all higher plants have a similar functional build, with organs for photosynthesis, to absorb nutrients and water, and for reproduction.

Plants’ vital processes include photosynthesis, growth, environmental adaptations and vascular transport.

Earth Science: Biology – Plants and Fungi – Anatomy of Higher Plants

Nearly all plants with pathways (vessels) to carry liquids have the same basic structure: stems, leaves, and roots.

The basic components of a seed plant are the roots, leaves, stems or shoots, and at certain times of the year-flowers and fruit. The roots function to anchor the plant in the ground. Fine root hairs absorb water and dissolve minerals from the soil. Some plants, such as carrots, have thickened roots that are used to store nutrients. The plant later draws upon these reserves to produce flowers and fruit.

The stem is an integral part of the plant and supports the leaves, flowers, and fruit, as well as transport water and nutrients upward to the leaves. These vital materials are transported through narrow tubes known as vascular bundles. Shoots generally grow toward light and, in plants such as bushes and trees, develop a woody structure. Site of photosynthesis The green leaves of a plant produce nutrients using photosynthesis a process that occurs in chloroplasts located within the leaf cells.

Water and the sugar produced by photosynthesis are distributed through the vascular bundles to nourish cells. The vascular bundles can often be clearly seen as the veins on the underside of a leaf. The leaves draw carbon di- oxide from the air through slit-shaped openings called stomata. These are usually found on the undersides of leaves. Typically, stomata open in the daytime to release excess water and the oxygen produced during photo-synthesis.

The carbon dioxide is stored in the plant’s cells until it is needed. The cuticle, or upper surface of leaves, and sometimes the underside have a waxy coating to protect the plant from dehydration and the sun’s harsh rays.


Flowers are specialized forms of leaves. The sepals—which are usually green and resemble leaves— protect the flower before it opens. Colorful petals attract insects in search of nectar and animals looking for pollen. Within the petal ring, the plant’s reproductive organs (the male stamens and the female pistil) are divided into the style, ovary, and stigma The style connects the stigma and ovary, which contains the ovules that develop into seeds.

Each male stamen consists of a filament and an anther that holds pollen. After pollination, the ovule ripens into a seed; the ovary develops into a fruit. The fruit protects and disperses the seed. Its appearance is adapted to the plant’s seed distribution mechanism.