Amoeboid movement is a crawling-like type of movement accomplished by protrusion of cytoplasm

Cytoplasm

The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

 of the cell

Cell (biology)

The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 involving the formation of pseudopod

Pseudopod

Pseudopods or pseudopodia are temporary projections of eukaryotic cells. Cells that possess this faculty are generally referred to as amoeboids. Pseudopodia extend and contract by the reversible assembly of actin subunits into microfilaments...

ia. The cytoplasm slides and forms a pseudopodium in front to move the cell forward. This type of movement has been linked to changes in action potential

Action potential

In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...

; the exact mechanism is still unknown. This type of movement is observed in amoeboids, slime molds and some protozoa

Protozoa

Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...

ns, as well as some cells in humans such as leukocytes

White blood cell

White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...

. Sarcoma

Sarcoma

A sarcoma is a cancer that arises from transformed cells in one of a number of tissues that develop from embryonic mesoderm. Thus, sarcomas include tumors of bone, cartilage, fat, muscle, vascular, and hematopoietic tissues...

s, or cancers arising from connective tissue cells, are particularly adept at amoeboid movement, thus leading to their high rate of metastasis.

Locomotion of amoeba occurs due the sol-gel conversion of the cytoplasm
within its cell. The ectoplasm

Ectoplasm (cell biology)

Ectoplasm refers to the outer, non-granulated part of a cell's cytoplasm. This is opposed to the endoplasm which is the inner layer of the cytoplasm, and often is granulated. It is clear, and protects as well as transports things within the cell. Moreover, large numbers of actin filaments...

 being called the plasma gel and the endoplasm

Endoplasm

Endoplasm generally refers to the inner part of a cell's cytoplasm. This is opposed to the ectoplasm which is the outer layer of the cytoplasm....

the plasma sol. The conversion of the endoplasm to ecto and vice versa is called sol-gel conversion.