How many cells a dolphin have in it body

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Anormal appearing couple is found to be heterozygous recessive for albinism both have the genotype aa the gene responsible for albinism is recessive to the normal pigment-producing gene what are the changes of their children being albino

Injuries in the environment are a result of