Search results
Results from the WOW.Com Content Network
Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues, or organs under sterile conditions on a nutrient culture medium of known composition. It is widely used to produce clones of a plant in a method known as micropropagation .
T cells are one of the important types of white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell surface. T cells are born from hematopoietic stem cells, [1] found in the bone marrow.
A nineteenth-century illustration showing the morphology of the roots, stems, leaves and flowers of the rice plant Oryza sativa. Plant anatomy is the study of the structure of plant cells and tissues, whereas plant morphology is the study of their external form. [177] All plants are multicellular eukaryotes, their DNA stored in nuclei.
These cells may be cells isolated from a donor organism (primary cells) or an immortalised cell line. The cells are bathed in a culture medium, which contains essential nutrients and energy sources necessary for the cells' survival. [8] Thus, in its broader sense, "tissue culture" is often used interchangeably with "cell culture".
The T helper cells (T h cells), also known as CD4 + cells or CD4-positive cells, are a type of T cell that play an important role in the adaptive immune system. They aid the activity of other immune cells by releasing cytokines .
These cells were named central memory T cells (T CM). They effectively stimulate dendritic cells, and after repeated stimulation they are able to differentiate in CCR7- effector memory T cells. Both populations of these memory cells originate from naive T cells and remain in the body for several years after initial immunization. [14]
This is a diagram of cell elongation in a plant. In sum, the acidity within the cell wall as a result of a high proton concentration in the cell wall. As a result,the cell wall becomes more flexible so that when water comes into the plant vacuole, the plant cell will elongate. This image shows the development of a normal plant.
The tapetum is a specialised layer of nutritive cells found within the anther of flowering plants, located between the sporogenous tissue and the anther wall. Tapetum is important for the nutrition and development of pollen grains and a source of precursors for the pollen coat. [ 1 ]