The stem of the plant should be cut at least three to four inches above the surface level.
The glass capillary should be tightly fixed with the stem.
The initial water level and the final water level should be carefully noted.
The droplets on the leaves should be observed and conclude that these drops are not from transpiration.
The answer would be A—the molecular formula given is that of a long-chain, saturated fatty acid, which would be insoluble in water (i.e., hydrophobic).
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B describes carbohydrates, which can function as a storage of energy (e.g., starch or glycogen) or structural components (e.g., cellulose). The three examples just given are polymers of glucose, a monosaccharide; monosaccharide generally have the empirical formula CH2O; this is not the empirical formula of the given molecule (and, in any case, there are too few oxygen atoms for the number of carbon atoms), and so B is incorrect.
C describes an amino acid, likely an α-amino acid, which consist of a central, saturated carbon bonded to amino (—NH2) and carboxyl (—C(=O)OH) functional groups and a variable side chain, which determines the amino acid’s properties. Since the formula of an amino acid must contain nitrogen, which the formula given doesn’t have, the molecule couldn’t be an amino acid, and so C is incorrect.
D describes nucleic acids. Examples include DNA and RNA; nucleic acids and the nucleotide monomers that comprise them contain a nitrogenous base and a phosphate group. The given molecule’s formula has neither nitrogen nor phosphorus, and so cannot represent an amino acid, making D incorrect.
The answer is D. Food Threshold is the amount of food capable on feeding the organisms.
Explanation:
1. any substance that kills germs
ans. germicide
2. drugs that attack specific bacteria
ans. antibiotics
3. substance that attacks fungi
ans. antifungal agents
4. chemical that destroyed pathogens inside the body
ans. anti-infective
