Is a process where the body experiences nutritional stresses or stimuli at critical developmental periods where the body's metabolism is permanently affected.

Solution:

Fetal programming occurs during embryonic and fetal development, a critical period in which tissues and organs are created. Insufficient nutrition during this time results in permanent alterations to certain structural and physiological metabolic functions of the fetus. British epidemiologist Barker first established the hypothesis, known as the "Barker hypothesis,” which states such programmed changes during this critical period predispose the fetus to certain postnatal diseases. The critical period coincides with the timing of rapid cell differentiation. Essentially, it refers to the process of sustaining or affecting a stimulus or impairment that occurs at a crucial point in its development.

Rickets has long demonstrated that under nutrition in the critical early stages of life brings about a continuing change in structure. A recent new doctrine suggests that fetal programming can affect diseases in adulthood. That is, the body's “memory” of under nutrition during the early stages of development translates into a pathology that determines future diseases. This idea is based on animal studies that demonstrate how under nutrition in utero can alter blood pressure, cholesterol metabolism, insulin response to glucose, and other metabolic, endocrine, and immune functions important to human diseases. This paper reviews evidence of the correlation between fetal under nutrition and diseases found in previous studies and considers the mechanism of fetal programming and the role of the placenta.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.