Answer:
The answers you have chosen are/should correct
Explanation:
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Answer:
D: A density-independent factor.
Explanation:
An earthquake is a density-independent limiting factor
The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which saves water.
Nitrogenous waste in the body tend to form toxic ammonia, which must be excreted. Mammals such as human excrete urea, while birds, reptiles, and some terrestrial invertebrates produce uric acid as waste in the form of a white paste or power. The production of uric acid involves a complex metabolic pathway that is energetically costly in comparison to processing of other nitrogenous wastes such as urea or ammonia, it has the advantages of reducing water loss and, hence, reducing the need for water.
The origin of congenital adrenal hyperplasia occurs when circulating cortisol levels are low.
Congenital adrenal hyperplasia (CAH) is an autosomal recessive disease which results from mutations of genes for enzymes involved in the biochemical steps of production of mineralocorticoids, glucocorticoids or sex steroids from cholesterol by the adrenal glands (steroidogenesis). <span>Low cortisol production results in rising levels of ACTH (adrenocorticotropic hormone) because cortisol usually inhibits ACTH production. This increased ACTH production induces overgrowth (hyperplasia) and overactivity of the steroid-producing cells of the adrenal cortex.</span>
