Answer:
Genes & DNA
Explanation:
Heritable traits are known to be passed from one generation to the next via DNA, a molecule that encodes genetic information.Organisms inherit genetic material from their parents in the form of homologous chromosomes, containing a unique combination of DNA sequences that code for genes.
eukaryote is a single celled organism, so that is almost like every organism on earth (except for bacteria). so actually there are many examples
1. bananas
2. algae
3. a spider
4. a lion
5. mushroom
4. tress, grass, flowers, pines....etc
5. humans
6. cancer cells, animal cells, sperm cells, muscle cells, plant cells...etc
5. flies almost every type of fly
6. fish
so yeah you get it almost every organism is a single celled organism :D
(except for bacteria and virus)