Which statement best describe a chromosome? A. It is a single piece of DNA that contains genes.
O B. It forms the hereditary material of all life on Earth.
OʻC. It is the passing of characteristics from one generation to the next.
O D. It is the part of a chromosome that ties together two chromatids.

A

Explanation: It most definetly not B, becuase not every form of life has DNA. A chromosome is a single chain of DNA that is coiled and super coiled to form dense thread-like pieces. The term chromosome is derived from the Greek words "chroma" or color and "some" or body and is so named because chromosomes have the ability to be stained with dyes.

the last one: artificial selection/genetic engineering

plant breeding is modifying the genetic composition of the plant - but this isn't cloning (which is specifically introducing a gene into a genome). but you are artificially selecting for the phenotype that you want.

the second one is literally genetic engineering - the gene would have been cloned first and then inserted or genetically engineered into the new plant cell (the cotton).