What is the difference between leaf cell and root cell

Unlike animals, however, plants use energy from sunlight to form sugars during photosynthesis. In addition, plant cells have cell walls, plastids, and a large central vacuole: structures that are not found in animal cells. Each of these cellular structures plays a specific role in plant structure and function. In plants, just as in animals, similar cells working together form a tissue. When different types of tissues work together to perform a unique function, they form an organ; organs working together form organ systems.

Vascular plants have two distinct organ systems: a shoot system, and a root system. The shoot system consists of two portions: the vegetative non-reproductive parts of the plant, such as the leaves and the stems, and the reproductive parts of the plant, which include flowers and fruits.

The shoot system generally grows above ground, where it absorbs the light needed for photosynthesis. The root system , which supports the plants and absorbs water and minerals, is usually underground. Figure 6 shows the organ systems of a typical plant. Figure 6. The shoot system of a plant consists of leaves, stems, flowers, and fruits. The root system anchors the plant while absorbing water and minerals from the soil.

Figure 7. Leaves are attached to the plant stem at areas called nodes. An internode is the stem region between two nodes. The petiole is the stalk connecting the leaf to the stem. The leaves just above the nodes arose from axillary buds. Stems are a part of the shoot system of a plant. They may range in length from a few millimeters to hundreds of meters, and also vary in diameter, depending on the plant type. Stems are usually above ground, although the stems of some plants, such as the potato, also grow underground.

Stems may be herbaceous soft or woody in nature. Their main function is to provide support to the plant, holding leaves, flowers and buds; in some cases, stems also store food for the plant. A stem may be unbranched, like that of a palm tree, or it may be highly branched, like that of a magnolia tree. The stem of the plant connects the roots to the leaves, helping to transport absorbed water and minerals to different parts of the plant.

It also helps to transport the products of photosynthesis, namely sugars, from the leaves to the rest of the plant. Plant stems, whether above or below ground, are characterized by the presence of nodes and internodes Figure 7.

Nodes are points of attachment for leaves, aerial roots, and flowers. The stem region between two nodes is called an internode. The stalk that extends from the stem to the base of the leaf is the petiole.

An axillary bud is usually found in the axil—the area between the base of a leaf and the stem—where it can give rise to a branch or a flower. The apex tip of the shoot contains the apical meristem within the apical bud.

Figure 8. The stem and other plant organs arise from the ground tissue, and are primarily made up of simple tissues formed from three types of cells: parenchyma, collenchyma, and sclerenchyma cells. Parenchyma cells are the most common plant cells Figure 8. They are found in the stem, the root, the inside of the leaf, and the pulp of the fruit. Parenchyma cells are responsible for metabolic functions, such as photosynthesis, and they help repair and heal wounds.

Some parenchyma cells also store starch. In Figure 8, we see the central pith greenish-blue, in the center and peripheral cortex narrow zone 3—5 cells thick just inside the epidermis ; both are composed of parenchyma cells. Vascular tissue composed of xylem red and phloem tissue green, between the xylem and cortex surrounds the pith. Collenchyma cells are elongated cells with unevenly thickened walls Figure 9.

They provide structural support, mainly to the stem and leaves. These cells are alive at maturity and are usually found below the epidermis. Figure 9. Collenchyma cell walls are uneven in thickness, as seen in this light micrograph. They provide support to plant structures. Sclerenchyma cells also provide support to the plant, but unlike collenchyma cells, many of them are dead at maturity. There are two types of sclerenchyma cells: fibers and sclereids.

Both types have secondary cell walls that are thickened with deposits of lignin, an organic compound that is a key component of wood. Fibers are long, slender cells; sclereids are smaller-sized. Sclereids give pears their gritty texture. Humans use sclerenchyma fibers to make linen and rope Figure Figure The central pith and outer cortex of the a flax stem are made up of parenchyma cells.

Inside the cortex is a layer of sclerenchyma cells, which make up the fibers in flax rope and clothing. Humans have grown and harvested flax for thousands of years. In b this drawing, fourteenth-century women prepare linen. The c flax plant is grown and harvested for its fibers, which are used to weave linen, and for its seeds, which are the source of linseed oil. Some plant species have modified stems that are especially suited to a particular habitat and environment Figure A rhizome is a modified stem that grows horizontally underground and has nodes and internodes.

Vertical shoots may arise from the buds on the rhizome of some plants, such as ginger and ferns. Corms are similar to rhizomes, except they are more rounded and fleshy such as in gladiolus.

Corms contain stored food that enables some plants to survive the winter. Stolons are stems that run almost parallel to the ground, or just below the surface, and can give rise to new plants at the nodes.

Runners are a type of stolon that runs above the ground and produces new clone plants at nodes at varying intervals: strawberries are an example. Tubers are modified stems that may store starch, as seen in the potato Solanum sp.

A bulb , which functions as an underground storage unit, is a modification of a stem that has the appearance of enlarged fleshy leaves emerging from the stem or surrounding the base of the stem, as seen in the iris. Stem modifications enable plants to thrive in a variety of environments.

Shown are a ginger Zingiber officinale rhizomes, b a carrion flower Amorphophallus titanum corm c Rhodes grass Chloris gayana stolons, d strawberry Fragaria ananassa runners, e potato Solanum tuberosum tubers, and f red onion Allium bulbs.

Watch botanist Wendy Hodgson, of Desert Botanical Garden in Phoenix, Arizona, explain how agave plants were cultivated for food hundreds of years ago in the Arizona desert in this video: Finding the Roots of an Ancient Crop.

Some aerial modifications of stems are tendrils and thorns Figure Tendrils are slender, twining strands that enable a plant like a vine or pumpkin to seek support by climbing on other surfaces. Found in southeastern United States, a buckwheat vine Brunnichia ovata is a weedy plant that climbs with the aid of tendrils. This one is shown climbing up a wooden stake. Leaves are the main sites for photosynthesis: the process by which plants synthesize food.

Most leaves are usually green, due to the presence of chlorophyll in the leaf cells. However, some leaves may have different colors, caused by other plant pigments that mask the green chlorophyll. The thickness, shape, and size of leaves are adapted to the environment. Each variation helps a plant species maximize its chances of survival in a particular habitat.

Usually, the leaves of plants growing in tropical rainforests have larger surface areas than those of plants growing in deserts or very cold conditions, which are likely to have a smaller surface area to minimize water loss. Deceptively simple in appearance, a leaf is a highly efficient structure.

Each leaf typically has a leaf blade called the lamina , which is also the widest part of the leaf. Some leaves are attached to the plant stem by a petiole. Leaves that do not have a petiole and are directly attached to the plant stem are called sessile leaves.

Small green appendages usually found at the base of the petiole are known as stipules. Most leaves have a midrib, which travels the length of the leaf and branches to each side to produce veins of vascular tissue. The edge of the leaf is called the margin.

Figure 13 shows the structure of a typical eudicot leaf. Within each leaf, the vascular tissue forms veins. The arrangement of veins in a leaf is called the venation pattern. Monocots and dicots differ in their patterns of venation Figure Monocots have parallel venation; the veins run in straight lines across the length of the leaf without converging at a point.

In dicots, however, the veins of the leaf have a net-like appearance, forming a pattern known as reticulate venation. One extant plant, the Ginkgo biloba , has dichotomous venation where the veins fork. The netlike venation in this b linden Tilia cordata leaf distinguishes it as a dicot.

The c Ginkgo biloba tree has dichotomous venation. The arrangement of leaves on a stem is known as phyllotaxy. Leaves are classified as either alternate, spiral, or opposite. Plants that have only one leaf per node have leaves that are said to be either alternate—meaning the leaves alternate on each side of the stem in a flat plane—or spiral, meaning the leaves are arrayed in a spiral along the stem. In an opposite leaf arrangement, two leaves arise at the same point, with the leaves connecting opposite each other along the branch.

If there are three or more leaves connected at a node, the leaf arrangement is classified as whorled. Leaves may be simple or compound Figure In a simple leaf , the blade is either completely undivided—as in the banana leaf—or it has lobes, but the separation does not reach the midrib, as in the maple leaf. In a compound leaf , the leaf blade is completely divided, forming leaflets, as in the locust tree. Each leaflet may have its own stalk, but is attached to the rachis.

A palmately compound leaf resembles the palm of a hand, with leaflets radiating outwards from one point Examples include the leaves of poison ivy, the buckeye tree, or the familiar houseplant Schefflera sp. Pinnately compound leaves take their name from their feather-like appearance; the leaflets are arranged along the midrib, as in rose leaves Rosa sp. Leaves may be simple or compound.

In simple leaves, the lamina is continuous. The a banana plant Musa sp. In compound leaves, the lamina is separated into leaflets. Compound leaves may be palmate or pinnate. In b palmately compound leaves, such as those of the horse chestnut Aesculus hippocastanum , the leaflets branch from the petiole. It therefore controls the movement of substances in and out of the cell. Mitochondria Organelles that contain the enzymes for respiration, and where most energy is released in respiration.

Ribosomes Tiny organelles where protein synthesis occurs. Plant cells also have additional structures: Function Chloroplasts Organelles that contains the green pigment, chlorophyll, which absorbs light energy for photosynthesis. Contains the enzymes needed for photosynthesis. Cell wall Made from cellulose fibres it strengthens the cell and supports the plant. Permanent vacuole Filled with cell sap to help keep the cell turgid.

Specialised plant cells There are many different types of cells in plants. A jelly-like material that contains dissolved nutrients and salts and structures called organelles. Contains genetic material, including DNA, which controls the cell's activities.

Its structure is permeable to some substances but not to others. Organelles that contain the enzymes for respiration, and where most energy is released in respiration. Tiny organelles where protein synthesis occurs. Never have chloroplasts.

Lack a cell wall, and have no central vacuole. Return to top. This Elodea leaf cell exemplifies a typical plant cell. It has a nucleus, and a stiff cell wall which gives the cell its box-like shape. The numerous green chloroplasts allow the cell to make its own food by photosynthesis.

The central vacuole takes up most of the volume of the cell. It is transparent, but you can see where it's pressing the chloroplasts up against the cell wall, especially at the ends of the cell. Like animal cells, the cytoplasm of this plant cell is bordered by a cell membrane. The membrane is so thin and transparent that you can't see it, but it is pressed against the inside of the cell wall.

This cell was alive and at x magnification when it was photographed.