Are all the characteristics of the leaves the same

Leaves, one of the vegetative organs of vascular plants. Its function is to carry out photosynthesis to synthesize organic matter, and it has transpiration, providing the power for the root system to absorb water and mineral nutrients from the outside world. Those with three parts: leaf, petiole and supporting leaf are called "complete leaves", such as missing petioles or supporting leaves are called "incomplete leaves"; It is divided into single leaf and compound leaf.

Leaves are the most environmentally sensitive organs in plants, and their morphological structure is the most likely to change with different ecological conditions to adapt to the environment. The leaves of different plants have a variety of forms, different sizes and different shapes. However, as far as a plant is concerned, it is relatively stable and can be used as a basis for identifying plants and taxonomic them.

At the same time, the leaf color is also diverse, generally speaking, the molecular ratio of chlorophyll to carotenoids in normal leaves is about 3:1, which makes the leaves appear green.

Compose. Leaves are generally composed of three parts: leaves, petioles and supporting leaves, such as the leaves of cotton, peach peas and other plants, and these three parts are called complete leaves. The leaves that lack any or two of these parts are called incomplete leaves, such as sweet potato, rape, sunflower, etc., and the leaves lack supporting leaves; The leaves of tobacco, lettuce, etc., lack petioles and supports; There are also some plants that have no leaves at all, only a flattened petiole on the stem, called a leaf-like stalk, such as the Taiwan acacia tree.

Composition of leaves. The leaves of grasses are different from the leaves of general plants, and it is composed of two parts: leaves and leaf sheaths. The leaves are linear or band-shaped, with longitudinal parallel veins. The leaf sheath is long and narrow and holds the stem, which has the role of protection, support and conduction.

Blade. Leaves are the most important components of leaves, mostly thin green flat bodies, this thin and flat form, with a large surface area, can shorten the distance between mesophyll cells and the leaf surface, and the leaf veins that play a supporting and conductive role are also in a network state. These characteristics are conducive to gas exchange and light energy absorption, the transport of water and nutrients and the output of photosynthetic products, and are perfect adaptation to photosynthesis and transpiration.

There are veins of different sizes distributed in the leaves, and along the longitudinal axis of the leaves, there is one of the most obvious veins called the main vein, and the rest of the veins are called lateral veins. Dicotyledons send out many lateral veins from the main vein to both sides, and the lateral veins then divide into thin veins, and the lateral veins and veins cross each other to form a network, which is called reticular veins; The main veins of monocots are obvious, and the lateral veins emanate from the base to the tip of the leaf, and the veins of each leaf are parallel, which is called parallel veins. Some lower angiosperms, ferns and gymnosperms have bifurcated leaf veins to form forked veins, which are relatively primitive leaf veins.

Leaves can be divided into leaf tips, leaf bases, leaf margins and other parts, and the morphological characteristics of each plant leaf can be used as one of the bases for identifying plants.

Petiole. The petiole is the stalk-like part that follows the base of the leaf, and its lower end is connected to the branch. The main function of the petiole is to guide and support, the petiole can twist and grow, thereby changing the position and direction of the leaf, so that the leaves do not overlap each other, and can fully receive sunlight, this characteristic is called leaf mosaic.

Stipule. The leaves are appendages at the base of the petiole and are often born in pairs. Its shape and function vary depending on the plant species, in addition to the protective effect on young leaves, some green leaves can also carry out photosynthesis.

The leaf morphology of various plants is varied, but they are all made up of leaves, petioles, and leaf receptacles. A leaf that contains a complete leaf, petiole and leaf tray is called a complete leaf. Some plants have leaves without leaf rests, others without petioles, and some plants have leaves without leaves.

Because in the evolution of the tree, and each tree is not.

Those who live with the environment and follow the trees.

Evolve!!

The shape of the leaves is determined by the attraction of the leaves to the tree or the scene in which the shape of the leaves occurs.

Because trees are not the same, their varieties are not the same.

The shape of the leaves is determined by the tree or the leaves.

Because in the process of the evolution of trees, trees in different places have evolved differently according to their living environment, and only today have they formed various different appearances, which is related to their living environment for thousands of years.

Because there are many species of trees, the shape of the leaves is different.

Because there are many species of trees, they are not of the same type, so the shape of the leaves is different.

Because that's the wonder of the Great Ran.

The varieties of trees are different, and the leaves are different.

If the tree is not the same, it will not be the same.

The shape of the leaves is different depending on the type of tree.

Because the leaves are like people, and no one in the world is the same, so the leaves are not the same!

Because trees are in different environments, in different climates.

Because the leaves have different shapes.

Because it's not the same in number, it's not the same in shape?

Why are the shapes of the various leaves different, and why are the shapes of the various leaves different?

Depending on the type of tree, so will the shape.

.Beggar: