Question

What Control characteristics or traits? How do they control those characteristics?

Answer 1

Characteristics or traits are usually demonstrated by genes which are present in the DNA packed into a compact structure of chromosomes. As we already know that genes are nothing but small sequences of DNA, deoxyribonucleic acid is compact in long strands of DNA. Many strands of DNA form chromosomes and they are tightly packed with proteins inside a cell.

Complete answer:
Genes are specifically short sequences of DNA, which express the genotypic and physical or morphological character. The traits are expressed as a result of a specific combination of alleles which are a pair of genes.
As we already knew that genes are part of DNA, and DNA is the inherited material of an organism which is transferred from one generation to another. By sexual reproduction females, as we know, contain two X chromosomes and male have one X chromosome and one Y chromosome. those are collectively called sex chromosomes.
DNA fragments are sequences of DNA which are cut by restriction enzymes and are stored in agarose gel. Agarose gel is a medium in which DNA travelled towards electrodes to show banding. This process is termed as gel electrophoresis. The technique is used to determine DNA size.
As DNA contains two strands which are complementary to each other but also, they can be antiparallel also. Complementary strands meaning one head part of strand having ${5'}$ hydroxyl group and the end part or the other strand ending having ${3'}$ group. In any DNA strand the strands initiating the template specially show-case this hydroxyl group.

Note:
Most probably, be it morphological trait or genetic trait higher chances of an offspring acquiring the trait is from both the parents or either one parent will be dominant and another parent will be recessive. Semi-conservative mode of replication is- copying from partially parent strand and new strand of DNA. Conservative on other hand led to replication from parent template strand.