The answer is Permian-Triassic extinction.
The Permian-Triassic extinction was 252 million years ago. It is known as The Great Dying because about 95% of all species died out due to environmental changes (volcanic eruptions, dry climate, melting of ice sheets, etc). This is also the only event in which many insect species wiped out.
All of the above- 1, 2, and 3 These introduce variation into the chromosome or into the zygote and create cells and offspring unique from the parents.
It's upset its not happy.
The pulmonary vein carries oxygenated blood from the lungs to the left atrium
