apical meristem

(noun)

the tissue in most plants containing undifferentiated cells (meristematic cells), found in zones of the plant where growth can take place at the tip of a root or shoot.

Related Terms

Examples of apical meristem in the following topics:

  • Meristems

    • The cells of the shoot and root apical meristems divide rapidly and are considered to be indeterminate, which means that they do not possess any defined end fate.
    • The apical meristem, also known as the "growing tip," is an undifferentiated meristematic tissue found in the buds and growing tips of roots in plants .
    • An active apical meristem lays down a growing root or shoot behind itself, pushing itself forward.
    • Each zone of the apical meristem has a particular function.
    • The apical meristem, pictured in the center of the leaves of this image, is also termed the "growing tip".

  • Structural Adaptations for Land in Seedless Plants

    • Shoots and roots of plants increase in length through rapid cell division in a tissue called the apical meristem, which is a small zone of cells found at the shoot tip or root tip .
    • The apical meristem is made of undifferentiated cells that continue to proliferate throughout the life of the plant.
    • A separate meristem, called the lateral meristem, produces cells that increase the diameter of tree trunks.
    • Addition of new cells in a root occurs at the apical meristem.
    • The root cap protects the fragile apical meristem as the root tip is pushed through the soil by cell elongation.

  • Genetic Control of Flowers

    • Flower development is the process by which angiosperms produce a pattern of gene expression in meristems that leads to the appearance of a flower.
    • the apical meristem must transform from a vegetative meristem into a floral meristem or inflorescence
    • A flower develops on a modified shoot or axis from a determinate apical meristem (determinate meaning the axis grows to a set size).
    • In the simple ABC model of floral development, three gene activities (termed A, B, and C-functions) interact to determine the developmental identities of the organ primordia (singular: primordium) within the floral meristem.
    • In order to achieve reproduction, the plant must become sexually mature, the apical meristem must become a floral meristem, and the flower must develop its individual reproductive organs.

  • Functions of Stems

    • The apex (tip) of the shoot contains the apical meristem within the apical bud.

  • Primary and Secondary Growth in Stems

    • It is the result of cell division in the shoot apical meristem .
    • It is caused by cell division in the lateral meristem .
    • Most primary growth occurs at the apices, or tips, of stems and roots.
    • Primary growth is a result of rapidly-dividing cells in the apical meristems at the shoot tip and root tip.
    • In woody plants, cork cambium is the outermost lateral meristem.

  • Auxins, Cytokinins, and Gibberellins

    • They also control the differentiation of meristem into vascular tissue and promote leaf development and arrangement.
    • Apical dominance (the inhibition of lateral bud formation) is triggered by auxins produced in the apical meristem.
    • Cytokinins are known to delay senescence in leaf tissues, promote mitosis, and stimulate differentiation of the meristem in shoots and roots.
    • For example, apical dominance seems to result from a balance between auxins that inhibit lateral buds and cytokinins that promote bushier growth.
    • GAs are synthesized in the root and stem apical meristems, young leaves, and seed embryos.

  • Blue Light Response

    • Darwin observed that light was perceived by the the apical meristem (tip of the plant), but that the plant bent in response in a different part of the plant.
    • The Darwins concluded that the signal had to travel from the apical meristem to the base of the plant, where it bent.

  • Mosses

    • Cells akin to an apical meristem actively divide and give rise to a gametophore, consisting of a photosynthetic stem and foliage-like structures.
    • Apical meristem-like cells divide and give rise to the gametophores.

  • Types of Root Systems and Zones of Growth

    • The zone of cell division is closest to the root tip and is made up of the actively-dividing cells of the root meristem, which contains the undifferentiated cells of the germinating plant.
    • Cell division occurs in the apical meristem.

  • The Evolution of Roots in Seedless Plants

    • The zone of cell division is closest to the root tip; it is made up of the actively-dividing cells of the root meristem.
    • Cell division occurs in the apical meristem.