The R group varies, and it is the carbon-phosphate backbone
Genetic variation is the variation in the DNA sequence in the genome of an organisms. Organisms of a species have similar characteristics but they are not identical due to genetic variation. Genetic variation is important in the survival and the adaptability of a given species of organism. Therefore, in this case lack of genetic variation necessary to adapt to change in the environment will lead to extinction of the fish species that lacks the variation.
The ultimate source of energy is sunlight, and living things must break the sunlight down using their own methods to use it.
Answer:
Index fossils represents the fossils of the organisms that lived in a particular geological time zone. The index fossils defines a geological time of a dead organisms. Index fossil ensures that a correct order of geological time appears in a fossil record. The index fossils of organisms that lived for a short period, were abundant and widespread geographically.
