"DNA molecules were discovered in the decade after Darwin's death. make up genes and chromosomes, which are basic hereditary units. initiate and guide the construction of complex sugars. are made up of three bases: adenine, cytosine, and factor. are the messenger molecules of RNA."

make up genes and chromosomes

Explanation:

Darwin is known for his theory of evolution which explained how the organism evolved on the planet and the Mendel is known for his explanation that how the traits are passed on to the generation.

But both were unaware of this that the factors which control the traits are composed of DNA.

The DNA was discovered in 1869 in the nucleus of the white blood cells but it was not established that the genetic material is the DNA as it was discovered later in 1944.  The later studies on the DNA showed that the DNA forms the genes which control the trait and are present on the chromosomes.

Thus, makeup genes and chromosomes is correct.