robert whittaker proposed the five kingdom classification of living organisms.
robert whittaker proposed the five kingdom classification of living organisms.
who proposed the five kingdom classification of living organisms?
robert whittaker
since 1969, life on earth was classified into five kingdoms, as introduced by robert whittaker. margulis became the most important supporter, as well as critic – while supporting parts, she was the first to recognize the limitations of whittaker's classification of microbes. but later discoveries of new organisms, such as archaea, and emergence of molecular taxonomy challenged the concept. by the mid-2000s, most scientists began to agree that there are more than five kingdoms. margulis became the most important defender of the five kingdom classification. she rejected the three-domain system introduced by carl woese in 1990, which gained wide acceptance. she introduced a modified classification by which all life forms, including the newly discovered, could be integrated into the classical five kingdoms. according to her the main problem, archaea, falls under the kingdom prokaryotae alongside bacteria (in contrast to the three-domain system, which treats archaea as a higher taxon than kingdom, or the six-kingdom system, which holds that it is a separate kingdom). her concept is given in detail in her book "five kingdoms", written with karlene v. schwartz. it is mainly because of her that this five-kingdom system survives.
lynn margulis
bioenergetics is the part of biochemistry concerned with the energy involved in making and breaking of chemical bonds in the molecules found in biological organisms. it can also be defined as the study of energy relationships and energy transformations and transductions in living organisms. the ability to harness energy from a variety of metabolic pathways is a property of all living organisms. growth, development, anabolism and catabolism are some of the central processes in the study of biological organisms, because the role of energy is fundamental to such biological processes. life is dependent on energy transformations; living organisms survive because of exchange of energy between living tissues/ cells and the outside environment. some organisms, such as autotrophs, can acquire energy from sunlight (through photosynthesis) without needing to consume nutrients and break them down. other organisms, like heterotrophs, must intake nutrients from food to be able to sustain energy by breaking down chemical bonds in nutrients during metabolic processes such as glycolysis and the citric acid cycle. importantly, as a direct consequence of the first law of thermodynamics, autotrophs and heterotrophs participate in a universal metabolic network—by eating autotrophs (plants), heterotrophs harness energy that was initially transformed by the plants during photosynthesis.
bioenergetics