apical

Examples of apical 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".

• Primary and Secondary Growth in Stems

  • It is the result of cell division in the shoot apical 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.
  • The influence of the apical bud on overall plant growth is known as apical dominance, which diminishes the growth of axillary buds that form along the sides of branches and stems.
  • If the apical bud is removed, then the axillary buds will start forming lateral branches.

• Functions of Stems

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

• 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.
  • 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

  • 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 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.

• Auxins, Cytokinins, and Gibberellins

  • Apical dominance (the inhibition of lateral bud formation) is triggered by auxins produced in the apical meristem.
  • 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.

• Chromalveolata: Alveolates

  • The apicomplexan protists are so named because their microtubules, fibrin, and vacuoles are asymmetrically distributed at one end of the cell in a structure called an apical complex .
  • The apical complex is specialized for entry and infection of host cells.
  • They have a characteristic apical complex that enables them to infect host cells.

• 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.

• Abscisic Acid, Ethylene, and Nontraditional Hormones

  • Another effect of ABA is to promote the development of winter buds; it mediates the conversion of the apical meristem into a dormant bud.
  • Strigolactones promote seed germination in some species and inhibit lateral apical development in the absence of auxins.

• Mosses

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