They do not use fossil fuels.
Answer: Germline mutation
A germline mutation is a mutation in the fully developed germ cells (sperm and ovum). These defective mutated cells fuse to form zygote. The zygote rapidly produces all somatic and germline cells in the offsprings which are also mutated. Therefore, mutation is transmitted from parents to offsprings. Cystic fibrosis is a result of germline mutation. This disease is hereditary in nature passes from parents to the offsprings. If a child receives CFTR (cystic fibrosis transmembrane conductance regulator) mutated gene from both the parents than the child will be affected by the symptoms of this disease. If the child receives a single copy of CFTR gene from either of the parent than the child will be the carrier of disease.The mutated gene may be present in the germline cells of the parent or on all the body cells.
The main food sources of the birds( the plentiful recourses within the environment occupied by the species)
