A gene may be described as

The correct answer for the fill in the blank is - A sequence of bases on the DNA that codes for a trait.

Gene is described as a segment of DNA ( deoxyribonucleic acid) that codes for a particular protein, which in turn corresponds to a trait/ characteristic of the living organism.

Gene is first transcribed into mRNA ( messenger RNA) through a process called transcription. mRNA is then converted into protein through a process called translation.

The protein thus formed corresponds to a particular trait ( like eye color, hair color).

i hope this helps

chordata is the answer

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.