Final answer:
In biology, the number of genes passed onto the next generation by an animal's relatives is known as inclusive fitness, part of population genetics, and is related to the concept of kin selection.
Step-by-step explanation:
The number of genes passed onto the next generation by an animal's relatives is referred to as inclusive fitness, which is a concept in the field of population genetics. Inclusive fitness takes into account not only the genes passed on by the individual themselves but also the genes passed on by its relatives. This is because relatives share a certain percentage of their genes due to common ancestry. Therefore, when relatives reproduce and pass on their genes, it can indirectly increase the genetic representation of the individual in the population. This concept is part of what is known as kin selection, which is where traits are favored because they benefit relatives of the individual, hence ensuring that shared genes are passed down to future generations.
Gene theory explains that many characteristics of living organisms are controlled by genes that are inherited from parents to offspring. These genes are essential for creating organisms that function and develop as members of their species, possessing inherited characteristics. In population genetics, scientists study the frequencies of alleles (variants of a gene) within populations, observing how selective pressures influence changes in allele and genotypic frequencies over time.