Answer: ammonia
Explanation: Nitrogenous wastes in the body tend to form toxic ammonia, which must be excreted. Mammals such as humans excrete urea, while birds, reptiles, and some terrestrial invertebrates produce uric acid as waste. Uricothelic organisms tend to excrete uric acid waste in the form of a white paste or powder
The smallest living unit is actually a cell. An organelle is an organ inside of a cell. An organelle would not be considered alive because it can not survive without the other organelles. Whereas, a cell can survive without other cells.
Answer:
False
Explanation:
In DNA double helix molecule, there are four types of nitrogenous bases: adenine, guanine, cytosine and thymine. Purines (i.e., adenine, guanine) and pyrimidines (i.e., cytosine and thymine) hold DNA strands together via hydrogen bonds. In base pairing, guanine always pairs with cytosine through 3 hydrogen bonds, while adenine always pairs with thymine by 2 hydrogen bonds. Hydrogen bonds are a type of dipole–dipole interaction where a hydrogen atom is covalently bonded to a very electronegative atom (e.g., Nitrogen or Oxygen).