Barr body
... inactive X chromosome results in an increase in
levels of Xist around the Xic . Meanwhile, on the future active X Tsix
levels are maintained; thus the
levels of Xist remain low. This shift allows Xist to ...
Chromatin
... respect to the DNA replication.
There are three
levels of chromatin organization:
nucleosome - ... -rich proteins.
Figure 2: Different
levels of DNA condensation. (1) Single DNA strand. (2) ... respect to the DNA replication.
There are three
levels of chromatin organization:
nucleosome - "beads ...
Diabetes mellitus
... and participation is vital as blood glucose
levels change continuously, while successfully keeping ... cells in the pancreas in response to rising
levels of glucose in the blood, as occurs after a meal. ... in liver and muscle cells. Lowered insulin
levels result in the reverse conversion of glycogen to ...
Insulin
... muscle) cells in the form of glycogen; lowered
levels of insulin cause liver cells to convert glycogen ... which is useful in reducing high blood glucose
levels in diabetes.
increased fatty acid synthesis ... or a bag of potato chips), human blood glucose
levels normally remain within a narrow range. In most ...
Nutrition
... issues, including poor nutrition and low
levels of exercise. Despite this knowledge, the peak of ... to excess of refined carbohydrates, decreasing
levels of exercise, fewer vegetables and fruit and the ... The body can be affected at the micro or macro
levels by nutrition, for example cancer can arise ...
Biology
... level of the ecosystem , for example when atmospheric carbon dioxide
levels rise, plants are able to grow better and thus remove more carbon dioxide ... share its habitat.
Ecological systems are studied at several different
levels from individuals and populations to ecosystems and biosphere level. ...
Kidney
... erythropoietin and renin and maintaining serum electrolyte, acid-base
levels and osmolality.
For more info see Renal physiology .
Diseases and ... is a toxic condition characterized by abnormal and dangerously high
levels of urea, creatinine, various body waste compounds, and other nitrogen-rich ...
Operator
...
Contents showTocToggle("show","hide")
1 Operators and
levels of abstraction
2 Describing operators
2.1 Notations
3 ...
4 Operators in physics
5 See also
Operators and
levels of abstraction
To begin with, the usage of operator in mathematics ...
Parthenogenesis
... way is due to their hormonal cycles, which cause some to act as males when
levels of estrogen are low, and others to take the role of female when estrogen
levels are high. Lizards that act out the courtship ritual have greater ...
Alga
... together, sometimes branching
Parenchymatous - cells forming a thallus with partial differentiation of tissues
In three lines even higher
levels of organization have been reached, leading to organisms with full tissue differentiation. These are the brown algae —some of which may reach ...
Antibody
... a single chain variable fragment (scFv), which retains the original specificity of the parent immunoglobulin.
A crude estimation of immunoglobulin
levels can be made by protein electrophoresis . Here the plasma proteins are separated into albumin , alpha-globulins (1 and 2), beta-globulins (1 and ...
Biodiversity
... . An advantage of this definition is that it seems to describe most instances of its use, and one possibly unified view of the traditional three
levels at which biodiversity has been identified:
genetic diversity - diversity of genes within a species. There is a genetic variability among ...
Bioinformatics
... programs through evolutionary principles.
Gene expression analysis
The expression of many genes can be determined by measuring mRNA
levels with multiple techniques including microarrays , expressed cDNA sequence tag ( EST ) sequencing, serial analysis of gene expression (SAGE) tag ...
Botany
... of whole plants. At the top end of this scale, plants can be studied in populations, communities and ecosystems (as in ecology ). At each of these
levels a botanist might be concerned with the classification ( taxonomy ), structure ( anatomy ), or function ( physiology ) of plant life.
Historically, ...
Chromosome
... and usually contains repetitive sequences.
Facultative heterochromatin , which is sometimes expressed.
Figure 2: Different
levels of DNA condensation. (1) Single DNA strand. (2) Chromatin strand ( DNA with histones ). (3) Chromatin during interphase with centromere . ...
Bioinformatics
... programs through evolutionary principles.
Gene expression analysis
The expression of many genes can be determined by measuring mRNA
levels with multiple techniques including microarrays , expressed cDNA sequence tag ( EST ) sequencing, serial analysis of gene expression (SAGE) tag ...
Dialysis
... diets (in addition to other dietary restrictions). This is because kidney failure usually includes an inability to properly regulate fluid
levels in the body. A session of hemodialysis may typically remove 2-5 kilograms (5-10 pounds) of fluid from the patient. The amount of fluid to be ...
Morphogenesis
... the nanos mRNA. Bicoid binds a specific RNA sequence in the 3' untranslated region of caudal mRNA and blocks translation.
Hunchback protein
levels in the early embryo are significantly augmented by new hunchback gene transcription and translation of the resulting zygotically produced mRNA. ...
Enhancer
... of DNA which can be bound with proteins (namely, the trans-acting factors, much like a set of transcription factors ) to enhance transcription
levels of genes (hence the name) in a gene-cluster. An enhancer does not need to be particularly close to the genes it acts on, but it is on the same ...
Extinction
... very rapidly, by killing all living members through contamination or sterilizing them. It can also occur over longer periods at lower toxicity
levels by affecting life span, reproductive capacity, or competitiveness. DDT played such a role in killing off bald eagles and other birds by thinning ...
Eye
... use, and light-sensitive organs are present in a variety of different creatures without any clear evolutionary link. However, eyes in different
levels various animals show adaption to their requirements (for example, birds of prey have much greater visual acuity than humans), and the different ...
Fungus
... .
When fungi do pass the resistance barriers of the human body and establish infections, the infections are classified according to the tissue
levels initially colonized. A fungal infection of the human body is called a mycosis .
The most common of human mycoses is caused by dermatophytes . ...
Gene regulatory network
... been interpreted as performing a kind information processing within cell which determine cellular behaviour. The basic drivers within cells are
levels of some proteins, which determine both spatial (tissue related) and temporal (developmental stage) co-ordinates of the cell, as a kind of "cellular ...
Homeostasis
... is still open to debate. However, some relatively simple homeostatic mechanisms are generally accepted. For example, when atmospheric carbon dioxide
levels rise, plants are able to grow better and thus remove more carbon dioxide from the atmosphere. When sunlight is plentiful and atmospheric temperature ...
Isozyme
... the quickest and cheapest marker systems to develop, and remain (as of 2005 ) an excellent choice for projects that only need to identify low
levels of genetic variation, e.g. quantifying mating systems .
References
Hunter, R. L. and C.L. Merkert. (1957) Histochemical demonstration of ...
Liver
... reach of science in the foreseeable future.
Diseases of the liver
Many diseases of the liver are accompanied by jaundice caused by increased
levels of bilirubin in the system. The bilirubin results from the breakup of the hemoglobin of dead red blood cells ; normally, the liver removes ...
Lynn Margulis
... the long-lasting intimacy of strangers. The fusion of genomes in symbioses followed by natural selection, she suggests, leads to increasingly complex
levels of individuality." [1]
" After the proposal of the endosymbiotic theory, Margulis predicted that if organelles were prokaryotic symbionts, ...
Lysozyme
... by attacking peptidoglycan by hydrolyzing the bond that connects N-acetylmuramic acid with carbon four of N-acetylglucosamine .
Lysozyme
levels in the blood are often increased in sarcoidosis .
In some forms of hereditary amyloid , the cause is a mutation in the lysozyme gene, which leads ...
Major histocompatibility complex
... immunologists for its pivotal role in the immune system, the MHC has also attracted the attention of many evolutionary biologists, due to the high
levels of allelic diversity found within many of its genes. Indeed, much theory has been devoted to explaining why this particular region of the genome ...
Memory
... Some psychologists, however, argue that the distinction between long- and short-term memories is arbitrary, and is merely a reflection of differing
levels of activation within a single store.
If we are given a random seven-digit number, we may remember it only for a few seconds and then forget ...
Microscope
... utilize light passing through the sample from below and special techniques are usually necessary to increase the contrast in the image to useful
levels (see contrast methods ). Typically, on a standard compound optical microscope, there are three objective lenses: a scanning lens (4×), low ...
Molecular evolution
... accumulation of a great deal of polymorphism. When Richard Lewontin and J. Hubby published their groundbreaking results in 1966 which showed high
levels of genetic variation in Drosophila via protein electrophoresis , the theoretical results from the infinite alleles model were used by Kimura and ...
Morphogenesis
... the nanos mRNA. Bicoid binds a specific RNA sequence in the 3' untranslated region of caudal mRNA and blocks translation.
Hunchback protein
levels in the early embryo are significantly augmented by new hunchback gene transcription and translation of the resulting zygotically produced mRNA. ...
Muscle
... myoclonus (twitching) and myalgia (muscle pain). Diagnostic procedures that may reveal muscular disorders include testing creatine kinase
levels in the blood and electromyography (measuring electrical activity in muscles).
Neuromuscular diseases are those that affect the muscles and/or ...
Nephron
... In this process urine is produced, and in doing so, eliminates wastes from the body, regulates blood volume and blood pressure , regulates the
levels of important electrolytes and metabolites and regulates blood pH levels.
Contents showTocToggle("show","hide")
1 Bowman's capsule ...
Natural selection
... realm (see, for example, Genetic programming ). Note also that this formulation does not rule out selection occurring at all biological
levels (e.g. gene, organism, group). Finally, note that the particular process of introducing new traits does not matter.
Darwin first outlined his ...
Neuroscience
... and learning is also a division of neuroscience.
The biological study of the human brain is an interdisciplinary field which involves many
levels of study, from the molecular level through the cellular level (individual neurons ), the level of relatively small assemblies of neurons like ...
Photon
... momenta of the modes and the number of photons in this mode.
Molecular absorption
A typical molecule , M , has many different energy
levels . When a molecule absorbs a photon, its energy is increased by an amount equal to the energy of the photon. The molecule then enters an excited ...
Photorespiration
... (specifically, the Calvin cycle ). Although rubisco favors carbon , it can also use oxygen , producing glycolate . This usually occurs when oxygen
levels are high; for example, when the stomata (tiny pores on the underside of the leaf ) are closed to prevent water loss.
The reaction is:
RuBP + ...
Alga
... together, sometimes branching
Parenchymatous - cells forming a thallus with partial differentiation of tissues
In three lines even higher
levels of organization have been reached, leading to organisms with full tissue differentiation. These are the brown algae —some of which may reach ...