DNA

... two strands so that another double-stranded segment can pass through. Unknotting is required for the ... biological processes can induce strain. A DNA segment with excess or insufficient helical twisting is ... end of the other at both ends of a double-helical segment makes the arrangement a " crab canon ". ...

Morphogenesis

... The expression patterns of the final class of segmentation genes, the segment polarity genes , are then fine-tuned by interactions between the cells of ... homeotic selector genes control the specializations of the third thoracic segment and the abdominal segments. In 1995 , the Nobel Prize for Physiology ...

Genetic recombination

... into a strand of DNA by means similar to that seen in crossover. A segment of DNA on the mobile element matches exactly with a segment of DNA on the target, allowing enzymes called integrases to insert the ...

Morphogenesis

... The expression patterns of the final class of segmentation genes, the segment polarity genes , are then fine-tuned by interactions between the cells of ... homeotic selector genes control the specializations of the third thoracic segment and the abdominal segments. In 1995 , the Nobel Prize for Physiology ...

Cilium

... the ovum from the ovary to the uterus . Opposite to the motile cilia, non-motile cilium usually exists as one cilium per cell. The outer segment of the rod photoreceptor cell in the human eye is connected to its cell body with a specialized non-motile cilium. The terminal fiber of the ...

Culture

... They thus used the term subculture to identify the cultures of parts of larger societies. Since subcultures reflect the position of a segment of society vis a vis other segments and the society as a whole, they often reveal processes of domination and resistance. Cultural change ...

Evolutionary developmental biology

... to account for morphological diversity. For example, there is significant variation in limb morphologies amongst salamanders and the differences in segment number in centipedes , even when the genetic variation is low. A big question then, for evo-devo studies is where does the novelty come from? If ...

Kidney

... filtration rate is a diagnostic test of kidney function . Kidney tissue The renal tubule is continuous with Bowman's capsule. The segment that drains glomerular filtrate from the Bowman's capsule is the proximal convoluted tubule . The next portion of the tubule is the loop of Henle , ...

Restriction enzyme

... the sequences of some artificial plasmids include a " linker " that contains dozens of restriction enzyme recognition sequences within a very short segment of DNA. So no matter the context in which a gene naturally appears, there is probably a pair of restriction enzymes that can snip it out, and which ...