What is the segment of a dna chain that codes for all or part of a trait?

gene

explanation:

each of the two alleles you inherit for a gene each may be strong ("dominant") or weak ("recessive"). when an allele is dominant, it means that the physical characteristic ("trait") it codes for usually is expressed, or shown, in the living organism. you need only one dominant allele to express a dominant trait. ; )

d. making up measurements to record.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.