Information:  - Plant cells are eukaryotic cells that differ in several key aspects from the cells of other eukaryotic organisms. Their distinctive features include:  - Volvox is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of up to 50,000 cells. They live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. "Volvox" diverged from unicellular ancestors approximately .  - Cyanobacteria , also known as Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. The name "cyanobacteria" comes from the color of the bacteria (= blue). Sometimes, they are called blue-green algae, and incorrectly so, because cyanobacteria are prokaryotes and the term "algae" is reserved for eukaryotes.  - Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and assimilated by the organism's cells to provide energy, maintain life, or stimulate growth.  - Pandorina is a genus of green algae composed of 8 , 16 , or sometimes 32 cells , held together at their bases to form a sack globular colony surrounded by mucilage . The cells are ovoid or slightly narrowed at one end to appear keystone - or pear - shaped . Each cell has two flagella with two contractile vacuoles at their base , an eyespot , and a large cup - shaped chloroplast with at least one pyrenoid . The colonies coordinate their flagellar movement to create a rolling , swimming motion . Pandorina shows the beginnings of the colony polarity and differentiation seen in Volvox since the anterior cells have larger eyespots . Molecular sequencing has shown that Pandorina is paraphyletic with respect to Volvulina . Asexual reproduction is by simultaneous division of all cells of the colony to form autocolonies that are liberated by a gelatinization of the colonial envelope . Sexual reproduction occurs by division of each cell of the colony into 16 - 32 zoogametes . Zoogametes show indications of heterogamy , a slight difference in the size and motility of the pairs that fuse to form the smooth walled zygote . ( Smith , 1920 , p. 95 ) .  - Pyrenoids are sub-cellular micro-compartments found in chloroplasts of many algae, and in a single group of land plants, the hornworts. Pyrenoids are associated with the operation of a carbon-concentrating mechanism (CCM). Their main function is to act as centres of carbon dioxide (CO) fixation, by generating and maintaining a CO rich environment around the photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Pyrenoids therefore seem to have a role analogous to that of carboxysomes in cyanobacteria.  - The Volvocaceae are a family of unicellular or colonial biflagellates, including the typical genus "Volvox". The family was named by Ehrenberg in 1834, and is known in older classifications as the Volvocidae. All species are colonial and inhabit freshwater environments.  - Chloroplasts are organelles, specialized subunits, in plant and algal cells. Their discovery inside plant cells is usually credited to Julius von Sachs (18321897), an influential botanist and author of standard botanical textbooks  sometimes called "The Father of Plant Physiology".  - In taxonomy, Volvulina is a genus of colonial green algae, specifically of the Volvocaceae. The colony (coenobium) is broadly ellipsoidal or spherical and consists of a fixed number of cells, usually 16 in mature individuals (rarely 4, 8 or 32). The cells are located at periphery of the coenobium and separated from each other by being embedded in a swollen sack. The cell body is lens-shaped or half spherical when mature with two flagella. The chloroplast is dish- or bowl-shaped. Pyrenoids may be present or absent, the stigma large. The nucleus is centrally located and there may be 4 to 8 contractile vacuoles. Sexual reproduction is by isogamy.  - Mucilage is a thick, gluey substance produced by nearly all plants and some microorganisms. It is a polar glycoprotein and an exopolysaccharide. Mucilage in plants plays a role in the storage of water and food, seed germination, and thickening membranes. Cacti (and other succulents) and flax seeds especially are rich sources of mucilage.  - Hornworts are a group of non-vascular plants comprising the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, the flattened, green plant body of a hornwort is the gametophyte plant.  - Algae (singular "alga" ) is an informal term for a large, diverse group of photosynthetic organisms which are not necessarily closely related, and is thus polyphyletic. Included organisms range from unicellular genera, such as "Chlorella" and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to 50 m in length. Most are aquatic and autotrophic and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem, which are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, "Spirogyra" and the stoneworts.  - Germination is the process by which a plant grows from a seed. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. In addition, the growth of a sporeling from a spore, such as the spores of hyphae from fungal spores, is also germination. Thus, in a general sense, germination can be thought of as anything expanding into greater being from a small existence or germ.    After reading the paragraphs above, we are interested in knowing the entity with which 'pandorina' exhibits the relationship of 'parent taxon'. Find the answer from the choices below.  Choices: - animal  - chlorella  - cyanobacteria  - flax  - plant  - prokaryotes  - volvocaceae  - volvox
The answer to this question is:
volvocaceae