Question

DNA occurs in
A. Nucleus
B. Chloroplast
C. Mitochondria
D. All the above

Answer 1

A molecule of deoxyribonucleic (DNA). It has the biological instructions which unify every species. DNA is passed on from adult organisms to their descendants during breeding together with its instructions.

Complete explanation:
Option A Nucleus: DNA is found within a particular area of the cell called the nucleus, which is named eukaryotic organisms. Due to their very small cell, and to the large number of DNA molecules per cell on organisms, the individual DNA molecules must be packaged closely. This packed DNA type is referred to as a chromosome.
Option A is correct.
Option B Chloroplast: Chloroplast has its own DNA, abbreviated frequently as cpDNA. The genome of other plastids is also known as plasmodium. Although the dinophyte algae are the notable exception, the genome of chloroplasts is divided into about $40$ little plasmids, each of which is $2,000$to $10,000$base pairs in length.
Option B is correct.
Option C Mitochondria: Mitochondrial DNA is the small circular chromosome within the mitochondria that is found. Mitochondria are organelles found at energy production sites in cells. Mitochondria is passed from mother to offspring, and thus mitochondrial DNA. There is a certain type of DNA within the mitochondrion. This is different from the DNA in the core.
Option C is correct.
Option D (All of the above): This option is suitable because chloroplasts have their own DNA within the nucleus, mitochondria and option.
Option D is correct.

Hence, option D is the correct answer.

Note:
A dual-stranded DNA molecule is replicated to produce two identical DNA molecules. The process is replicated. DNA replication is one of the most fundamental processes in a cell. Each time a cell is separated, it must contain the same genetic information or DNA as the parent cell, in the two daughter cells that result.