Classifying Different Cell Types (Plant/Animals Tissues) And Specify the Function(s) of Each Flashcards
> A process by which a cell changes from one cell type to another which allows cell to perform different functions from its previous statement.
> It is a complex process that involves large modifications in gene expression.
Cell Differentiation
> Undifferentiated cells, are a type of cells that have not yet specialized or matured into a specific cell type with a defined function.
> These cells are in their early developmental stage and have the potential to transform into various types of specialized cells found in the body, such as muscle cells, nerve cells, or blood cells.
Stem Cells
> Stem cells are undifferentiated cells characterized by their ability to:
• Self-renew: Divide and produce identical daughter stem cells.
• Differentiate: Transform into specialized cell types with specific functions.
Stem cells can be classified by 2 broad categories, which arepart subdivided according to the:
• Source of stem cells
• Differentiation process
What are the sources of stem cells?
• Embryonic stem cells
• Fetal stem cells
• Adult stem cells
• Umbilical cord cells
What are the stem cells based on differentiation potential?
• Totipotent stem cells
• Pluripotent stem cells
• Multipotent stem cells
• Sources: Derived from early-stage embryos.
• Properties: Pluripotent, meaning
they can become any cell type in the body.
Embryonic stem cells
• Source: Found in various tissues and organs of the adult body.
• Properties: Typically multipotent, specializing in cell types related to their tissue of origin.Play a crucial role in tissue maintenance, repair, and regeneration within their resident tissues.
Adult stem cells
Source: Collected from the umbilical cord and placenta after childbirth.
Properties: Multipotent, with the ability to differentiate into various blood cell types.
Umbilical cord cells
Potency: are the most versatile.
Capability: They can give rise to any cell type in the body, as well as the cells needed to support the development of an entire organism, including the placenta. Have the remarkable ability to develop into all cell types necessary to form a complete and functional organism.
Example: Fertilized egg (zygote), as it can develop into a complete organism.
Totipotent stem cells
Potency: Pluripotent stem cells are highly versatile but not as much as totipotent cells.
Capability: They can differentiate into nearly all cell types found in the adult body, excluding the cells needed for placental development. Can give rise to a wide range of cell types, they do not have the capacity to develop into all the different cell types necessary to form a complete, functioning organism.
Example: Embryonic stem cells (ESCs), as they can become a wide range of cell types.
Pluripotent stem cells
Potency: Are more specialized than pluripotent cells.
Capability: They can differentiate into a limited range of cell types, usually related to a specific tissue or organ.
Example: Hematopoietic stem cells (found in bone marrow), as they can become various types of blood cells but not other tissue types.
Multipotent stem cells
Are innately undifferentiated cells located in the meristems of plants. They serve as the origin of plant vitality, as they maintain themselves while providing a steady supply of precursor cells to form differentiated tissues and organs in plants.
Plant stem cells
Three distinct areas of stem cells are recognized:
• Apical meristem
• Intercalary meristem
• Lateral meristem.
He coined the term “meristem.” Meristematic tissue contains undifferentiated cells, which are the building blocks of the specialized plant structures.
Carl Wilhelm von Nägeli
•The
earliest
and
youngest
meristematic tissue.
•It originates from the
embryo.
•The
primary
meristem arises from
this.
•It is found in the root
and the shoot tips.
Promeristem
•It
arises
from
the
promeristem.
•Cells divide actively.
•It is present below the
promeristem and forms the
permanent tissue.
Primary Meristem
•It originates from the primary
meristem.
•The permanent tissue forms
from the secondary meristem.
Secondary Meristem
• Location: At the tips of plant shoots (shoot apical meristem) and
amino (root apical meristem).
• Function: Responsible for primary growth, leading to the elongation
of the plant body and the formation of new leaves, stems, and
roots.
• Differentiation: Cells from apical meristems can differentiate into
various types of plant tissues.
• Apical meristem is divided into-promeristem zone, which contains actively dividing cells, and the meristematic zone, which contains
protoderm, procambium and ground meristem.
Apical Meristem
• Location: It is in the leaves and
internodes at the intercalary
position.
• Function: These help to increase
the length of the internode.
• Differentiation: It is found in grass,
monocots and pines. It is a part of
apical meristem and adds to the
height of the plant.
Intercalary Meristem
