Genes are:
A) rod-shaped structures located in each human nucleus.
B) the blueprint for creating all of the traits that organisms carry.
C) sex cells that combine to create a unique individual.
D) identical molecules for every existing species on earth.

Question

Quizplus · Accepted Answer

Genes are segments of DNA that contain the instructions for creating proteins, which ultimately determine an organism's traits. Therefore, genes are the blueprint for creating all of the traits that organisms carry.

Answer A, rods-shaped structures located in each human nucleus, describes chromosomes rather than genes. 
Answer C, sex cells that combine to create a unique individual, refers to gametes, which carry half the genetic information necessary to create a new individual. 
Answer D, identical molecules for every existing species on earth, is incorrect as genes differ between species and even between individuals within a species.

Genes Are