Answer:
chromosomes.
Explanation:
Chromosomes occur as strands of long-chain protein molecules called DNA. Chromosomes are made up of two strands each called chromatid . The chromatids are joined at a point called centromere. During prophase, the chromosomes become tightly coiled and so appear shorter and thicker. Parts of chromosomes form functional units called genes which determine different activities of the cell. Genes are hereditary and can be transmitted from parent to off-spring.
