Answer:
A) 50%
Explanation:
Boxes 2 and 3 are heterozygous because solving the punnet square results in those boxes being Tt
False because many different species are going extinct within our lifetime
Oxygen entered the Earth's atmosphere after the appearance of the Great Oxidation Event (Great Oxygenation Event). The Great Oxidation is the first mass extinction on Earth.
The Great Oxidation lasted 2.4 to 2.0 billion years ago.
Oxygen appeared on Earth thanks to cyanobacteria using photosynthesis.
Domain kingdom phylum class order family genus species