The complex structures of DNA and protein found in the cell nucleus are mitochondria. nucleoplasm. histones. nucleases. chromosomes.

chromosomes

Explanation:

Genomics refers to the scientific study of genes (DNA) found in living organisms such as humans and animals.

A genome can be defined as the complete set of hereditary instructions that is typically found in the deoxyribonucleic acid (DNA).

The complex structures of deoxyribonucleic acid (DNA) and protein found in the cell nucleus are generally referred to as chromosomes.

In sexual reproduction, the chromosomes from parents are found in the cell nucleus and are comprised of deoxyribonucleic acid (DNA), histone proteins, etc. Thus, they are used to store genetic informations in living organisms.

Basically, the human somatic cell is made up of 46 chromosomes which are sub-divided into 22 pairs of autosomes and a pair of sex chromosomes (X and Y). An autosome is one of the numbered chromosome that is typically not a sex chromosome.

On the other hand, sex chromosomes (X and Y) are responsible for determining the gender or sex of living organisms such as humans.

i think its the first one