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A crista (/ ˈ k r ɪ s t ə /; pl.: cristae) is a fold in the inner membrane of a mitochondrion. The name is from the Latin for crest or plume , and it gives the inner membrane its characteristic wrinkled shape, providing a large amount of surface area for chemical reactions to occur on.
Microscopic organisms were increasingly constrained in the plant/animal dichotomy. In 1858, the palaeontolgist Richard Owen was the first to define Protozoa as a separate kingdom of eukaryotic organisms, with "nucleated cells" and the "common organic characters" of plants and animals, although he also included sponges within protozoa. [28]
Among those with mitochondria, the mitochondrial cristae may be tubular, discoidal, or in some cases, laminar. Most excavates have two, four, or more flagella . [ 4 ] Many have a conspicuous ventral feeding groove with a characteristic ultrastructure , supported by microtubules —the "excavated" appearance of this groove giving the organisms ...
Eukaryotic cells are found in plants, animals, fungi, and protists. They range from 10 to 100 μm in diameter, and their DNA is contained within a membrane-bound nucleus. Eukaryotes are organisms containing eukaryotic cells. The four eukaryotic kingdoms are Animalia, Plantae, Fungi, and Protista. [12] They both reproduce through binary fission.
An amoeba of the genus Mayorella (Amoebozoa, Discosea). Amoebozoa is a large and diverse group, but certain features are common to many of its members. The amoebozoan cell is typically divided into a granular central mass, called endoplasm, and a clear outer layer, called ectoplasm.
In other words, the term Myzozoa, meaning "to siphon the contents from prey", may be applied informally to the common ancestor of the subset of alveolates that are neither ciliates nor colponemids. Predation upon algae is an important driver in alveolate evolution, as it can provide sources for endosymbiosis of novel plastids.
Cellular respiration is a vital process that occurs in the cells of all [[plants and some bacteria ]]. [ 2 ] [ better source needed ] Respiration can be either aerobic, requiring oxygen, or anaerobic; some organisms can switch between aerobic and anaerobic respiration.
The human population exploits and depends on many animal and plant species for food, mainly through agriculture, but also by exploiting wild populations, notably of marine fish. [ 10 ] [ 11 ] [ 12 ] Livestock animals are raised for meat across the world; they include (2011) around 1.4 billion cattle , 1.2 billion sheep and 1 billion domestic pigs .