deficiencies:
Situations in which there is not enough of something.

deforestation:
The wiping out of trees, by any means, in an area.

degrade:
To wear down by erosion.

denitrification:
An anaerobic biological process in which nitrates (NO3) are ultimately reduced to atmospheric nitrogen (N2).

densities:
(singular: density) The ratio of mass over volume.

derived:
A substance produced from another substance or substances.

dextran:
A white, gummy substance, produced from milk or molasses, used in candies and lacquers, as well as a substitute for blood plasma.

diabetics:
People affected by diabetes, a disease which interferes with people's ability to use sugar.

dialysis:
The purification of a colloid, such as blood, by passing it through a membrane.

diet staple:
A major element in the diet of a given culture or person.

dilating:
To make wider or larger; cause to expand.

diphtheria:
An acute and highly infectious disease caused by the bacillus Corynebacterium diphtheria.

dispersion:
A system of dispersed molecules suspended in a solid, liquid, or gas.

disseminated:
To scatter or spread widly.

distillate:
The product obtained from the condensation of vapours in distillation. See distillation.

distillation:
Separation of something by evaporating it, collecting the steam, and cooling it down.

DNA Deoxyribonucleic acid:
Concidered as a gene, the chemical structure of DNA is characterixed by sequences of four nitrogen bases (adenine, thymine, guanine and cytosine) occuring in one of the two nucleic acid chains and in a complementary fashion in the other.

domestic:
1. Inside the household. 2. Inside the country.

domestication:
The adaptation of an animal species to living with (and depending on) humans.

dyability:
The property of something allowing it to take and hold a pigment.
Index