biology-dictionary_11-06-2009

(ff) #1

Hematopoietic system
The system in the body which is responsible for the production of blood cells.
Hemicelluloses
Any of several polysaccharides that are more complex than a sugar and less complex than
cellulose, found in plant cell walls and produced commercially from corn grain hulls.
Hemichordata
A group of marine animals categorized as either a phylum of deuterostomes or a subphylum
of chordates; includes the Enteropneusta, Pterobranchia, and Graptolithina.
Hemoglobin
An iron-containing protein in red blood cells that reversibly binds oxygen.
Hemophilia
A group of hereditary disorders characterized by failure of the blood to clot and consequent
excessive bleeding from even minor wounds.
Hemolymph
In invertebrates with an open circulatory system, the body fluid that bathes tissues.
Hepatic
Pertaining to the liver.
Hepatic portal vessel
A large circulatory channel that conveys nutrient-laden blood from the small intestine to the
liver, which regulates the blood's nutrient content.
Herbaceous
In plants, nonwoody.
Herbivore
A heterotrophic animal that eats plants.
Heredity
The transmission of characteristics from parent to offspring.
Hermaphrodite
An individual that functions as both male and female in sexual reproduction by producing
both sperm and eggs.
Heterochromatin
Nontranscribed eukaryotic chromatin that is so highly compacted that it is visible with a
light microscope during interphase.

Free download pdf