H is the relative entropy of the target and background residue
frequencies. (Karlin and Altschul, 1990). H can be thought of
as a measure of the average information (in bits) available
per position that distinguishes an alignment from chance. At
high values of H, short alignments can be distinguished by chance,
whereas at lower H values, a longer alignment may be necessary.
(Altschul, 1991) (NCBI)
A single set of chromosomes (half the full set of genetic
material) present in the egg and sperm cells of animals and
in the egg and pollen cells of plants. Human beings have 23
chromosomes in their reproductive cells.
See also: diploid (ORNL)
Haplotype
A way of denoting the collective genotype of a number of closely
linked loci on a chromosome. (ORNL)
Hemizygous
Having only one copy of a particular gene. For example, in
humans, males are hemizygous for genes found on the Y chromosome.
(ORNL)
DNA sequence that is very similar across several different
types of organisms.
See also: gene, mutation
(ORNL)
High-throughput sequencing
A fast method of determining the order of bases in DNA.
See also: sequencing (ORNL)
Homeobox
A short stretch of nucleotides whose base sequence is virtually
identical in all the genes that contain it. Homeoboxes have
been found in many organisms from fruit flies to human beings.
In the fruit fly, a homeobox appears to determine when particular
groups of genes are expressed during development. (ORNL)
Collective name for several projects begun in 1986 by DOE to
create an ordered set of DNA segments from known chromosomal
locations, develop new computational methods for analyzing genetic
map and DNA sequence data, and develop new techniques and instruments
for detecting and analyzing DNA. This DOE initiative is now
known as the Human Genome Program. The joint national effort,
led by DOE and NIH, is known as the Human Genome Project. (ORNL)
