1. A gene is section of DNA that codes for a specific trait.
2. 2,001
I think the answer is B; that’s assuming that the other allele of the heterozygous brown eyed man is coding for blue eyes. If it’s not then my answers wrong. Tell me if you don’t understand or you need a step by step explaination
Answer:
Until recent history,extinctions have always happened gradually and on a small scale.
Explanation:
Extinction occur when environmental factors like natural disaster,habitat fragmentation,over exploitation,global change don't favor the survival of species thus gradually leads to extinction of species.
Some times human activity becomes the major problem for extinction.More over,poor reproduction,decline in population number and genetic inbreeding also leads to extinction.
99% of all species that exist on earth become disappeared.
Evolution leas to speciation which leas to formation of new species but species become extinct when they are unable to survive against competition.