The biological species concept is usually described as the largest group of organisms in which any two individuals of the proper mating varieties can generate fertile offspring, often by sexual reproduction. It refers to the classification containing related organisms that have common features and are capable of interbreeding.
A species, in biology, is the primary unit of classification as well as a taxonomic order of organisms. Furthermore, is a unit of biodiversity.
A collection of interbreeding individuals cannot be easily implemented to organisms that generate only or essentially asexually. Also, many plants, and some animals, form hybrids in nature. According to the biological species theory, organisms belong to the same species if they can interbreed to produce viable, fertile offspring. Species are divided from one another by prezygotic and postzygotic restrictions, which restrict mating or the generation of viable, fertile offspring.
You didn't add the choices, but I've had this question before the answer is that nearly all of the male immigrants were male, so children came from unions with Native Americans.
The first consequence was the widespread deaths and injuries. First World War had killed 10 million people and the Second World War had killed 20-25 million people. 2. The 2 wars had created a regime of lethal arms, especially in nuclear and chemical weapons.
