Lack of antibodies because thats the stuff to fight things away
The active site is <span> a site on the substrate molecule where specific enzyme molecules bind.</span>
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.
Answer:
1. an offspring with two identical alleles for a trait is homozygous.
2. only some traits are inherited
3. offspring inherit two alleles for a gene from each parent.
