In medicine, the BUN-to-creatinine ratio is the ratio of two serum laboratory values, the blood urea nitrogen (BUN) (mg/dL) and serum creatinine (mg/dL) (Cr).he normal range of urea nitrogen in blood or serum is 5 to 20 mg/dl, or 1.8 to 7.1 mmol urea per liter. The range is wide because of normal variations due to protein intake, endogenous protein catabolism, state of hydration, hepatic urea synthesis, and renal urea excretion.
The two most common types of asexual reproductive spores produced by molds are conidiospores and sporangiospores. Conidiospores are borne externally in chains on an aerial hypha called a conidiophore (see Fig.he two most common types of asexual reproductive spores produced by molds are conidiospores and sporangiospores. Conidiospores are borne externally in chains on an aerial hypha called a conidiophore (see Fig.
Spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes.y contrast, gametes are units of sexual reproduction. Spores form part of the life cycles of many plants, algae, fungi and protozoa. Bacterial spores are not part of a sexual cycle but are resistant structures used for survival under unfavourable conditions.