CELL
DIVERSITY
Cells group together to
form tissues. These tissues are made
of the same cell types or, in some cases, different cell types.
PLANT
TISSUES
The 4 main types of plant
tissues are dermal tissue, ground tissue, vascular tissue, and meristematic
tissue. These tissues are discussed on the Structure
of Flowering Plants webpage.
ANIMAL TISSUES
The 4 main types of animal tissues are epithelial tissue, connective
tissue, muscular tissue, and nervous tissue. These tissues are
discussed in the various web pages of this website. (See homepage)
Tissue
culture is the growth and multiplication of undifferentiated cells or specific
cell types in a sterile nutritive medium in the lab. Hormones and other growth
factors may also be present to keep the cell dividing and/or bring about
differentiation. This growth of cells and tissues is called in-vitro growth. This is contrasted to in-vivo growth which is growth within
the body.
TISSUE CULTURE APPLICATIONS
Micropropagation is a means to grow many plants from a
single plant. A single plant is cut into many pieces and grown in a nutrient
medium. New plants will form.
Cancer Research has been done with tissue cultures. Antibodies to fight cancer cells can be
produced using tissue cultures. Much more information is available on The Human Defence System
webpage.
ORGANS
An
organ is a group of different
tissues working together performing a specific job. Plant organs include roots,
stems, and leaves. Animal organs include the skin, heart, liver, and kidneys.
The
leaf includes dermal, vascular, and
ground tissue. The heart includes
muscle, epithelial, connective (blood) tissue.
ORGAN SYSTEMS
An
organ system is a group of different
organs operating together carrying out a definite task. Animals are composed of
many organ systems which all form the complete animal organism. Examples of animal organ systems are the circulatory,
nervous, endocrine, and reproductive systems.
In
summary the body is organised in the following way:
