Im not 100% sure but the best answer I can give is Prokaryotes because they came to be around the time oxygen did as well.
An Ovule is a plant organ that consists of an embryo, tissues and a protective coating.
In order for natural selection to take place we must have "variety in a population". This variety of traits is what allows natural selection to "pick" the most favorable traits.
Answer:
The hemoglobin of horse has 60% lower than the human's hemoglobin
The correct answer for both blanks is "Sodium".
Sodium ions are necessary in small quantities for some sorts of flora, but sodium as a nutrient is extra usually wanted in large quantities by using animals, due to their use of it for era of nerve impulses and for upkeep of electrolyte balance and fluid stability. In animals, sodium ions are vital for the aforementioned capabilities and for coronary heart hobby and sure metabolic functions.
