A multicellular organism is an organism that consists of more than one cell, in contrast to unicellular organism. All species of animals, land plants and...

unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists...

contain microorganisms. The third domain Eukaryota includes all multicellular organisms as well as many unicellular protists and protozoans that are microbes...

organelles. A multicellular organism such as an animal, plant, fungus, or alga is composed of many cells, often specialised. A colonial organism such as a...

around 1.7 Ga, multicellular organisms began to appear, with differentiated cells performing specialised functions. While early organisms reproduced asexually...

identify cells that share morphological or phenotypical features. A multicellular organism may contain cells of a number of widely differing and specialized...

Extracellular space refers to the part of a multicellular organism outside the cells, usually taken to be outside the plasma membranes, and occupied by...

In a multicellular organism, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ...

Differentiation happens multiple times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues...

that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent and thus the...

most other anisogamous organisms, a zygote is formed when an egg cell and sperm cell come together to create a new unique organism. The formation of a totipotent...

in all known organisms, being found in species as diverse as the unicellular bacterium Escherichia coli and huge multicellular organisms like elephants...

one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid...

An embryo is the initial stage of development for a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of...

extracellular fluid (ECF) denotes all body fluid outside the cells of any multicellular organism. Total body water in healthy adults is about 50–60% (range 45 to...

An immortalised cell line is a population of cells from a multicellular organism which would normally not proliferate indefinitely but, due to mutation...

have allowed organisms to go from a single cell organism to one of many cells. Soon after the emergence of these first multicellular organisms, a remarkable...

Prokaryotes are single-celled organisms such as bacteria, whereas eukaryotes can be either single-celled, such as amoebae, or multicellular, such as some algae...

may be a prerequisite for specialisation of cells, as an asexual multicellular organism might be at risk of being taken over by rogue cells that retain...

together as a whole. Microbes live everywhere in and on every multicellular organism. Many organisms rely on their symbionts in order to develop properly, this...

evolution of multicellular organisms is one of the major breakthroughs in evolution. The first step of converting a unicellular organism into a metazoan...

of a multicellular organism other than a gamete, germ cell, gametocyte or undifferentiated stem cell. Somatic cells compose the body of an organism and...

used as a model organism. It was the first multicellular organism to have its whole genome sequenced, and in 2019 it was the first organism to have its connectome...

multicellular organism found in 609-million-year-old rocks laid down during the Ediacaran period in the Guizhou Province of South China. The organism...

Mosaicism or genetic mosaicism is a condition in which a multicellular organism possesses more than one genetic line as the result of genetic mutation...

the late 1950s, the Precambrian was not believed to have hosted multicellular organisms. However, with radiometric dating techniques, it has been found...

coenobium), or multicellular, as in the phylum Bryozoa. Colonial organisms may have been the first step toward multicellular organisms. Individuals within...

to the expression of different sets of genes. All the cells in a multicellular organism derive from a single cell, differentiating into variant cell types...

of the germ line in sexually reproducing multicellular organisms. Gametes are the means by which an organism passes its genetic information to its offspring;...

early biogenic graphite to microbial mat fossils to fossilised multicellular organisms. Existing patterns of biodiversity have been shaped by repeated...