Semi Conservative Replication
The method of replication of DNA in which the molecule divides longitudinally, each half being conserved and acting as a template for the formation of a new strand
2. A model of DNA replication in which each daughter DNA molecule consists of one parental strand and one newly synthesized strand.

Senut, Brigitte
An anatomist at Frances National Museum of Natural History. In 2000, Senut and Martin Pickford discovered Orrorin tugensis, a proto-hominid dated at 6 million years old.

Sequence Tagged Site (STS)
Short (200 to 500 base pairs) DNA sequence that has a single occurrence in the human genome and whose location and base sequence are known. Detectable by polymerase chain reaction, STSs are useful for localizing and orienting the mapping and sequence data reported from many different laboratories and serve as landmarks on the developing physical map of the human genome. Expressed sequence tags (ESTs) are STSs derived from cDNAs.

Sequencing
Determination of the order of nucleotides (base sequences) in a DNA or RNA molecule or the order of amino acids in a protein.
2. The act of determining the amino acid pattern at a given gene location in an individual.

Sexduction
The process whereby a fragment of genetic material from one bacterium is carried with the sex factor F to a second bacterium.

Sex Influenced Inheritance
Phenotypic expression that is dependent on the sex of the individual. A heterozygote would express one phenotype in females and a different phenotype in males. An example of this is human male-pattern baldness.

Sex Influenced Trait
A phenotype that is conditioned by the sex of the individual; a gene may be dominant in males and recessive in females, or vice versa; the trait may be expressed only to a lesser degree in one sex.