DNA in the cell nucleus serves as the information source for making proteins. Different proteins are produced based on the information encoded in the DNA.

The information source for the inheritance of features is the DNA (Deoxyribo Nucleic Acid) molecules located in the chromosomes of the cell nucleus.

Organisms look similar because their body designs are similar, and these designs are based on similar blueprints.

We usually determine that two different individual organisms belong to the same species based on their similarity in appearance. Reproducing organisms create new individuals that share similarities with themselves, aiding in the classification of organisms into the same species.

Large numbers of organisms belonging to a single species increase their visibility. The abundance of reproducing individuals of a species draws attention and facilitates the study and understanding of that particular species.

Individual organisms engage in reproduction to create more individuals of their species. While it requires energy, reproduction is essential for the continuation of the species and the passing on of genetic information.

Organisms are noticed primarily due to their ability to reproduce. The existence of a large number of reproducing individuals within a species makes them more observable. Reproduction ensures the persistence and visibility of a species over time.

Populations of organisms fill well-defined places, or niches, in the ecosystem, utilizing their ability to reproduce.

The inbuilt tendency for variation during reproduction serves as the basis for evolution. The subtle differences in the surviving cells, caused by variations in DNA copies, contribute to the diversity and adaptation of organisms over time.