They turn brown because they begin to decompose..which is why bananas are biodegradeble because they are able to become decomposed by other living things
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.
Answer:
In areas of Africa where malaria is prevalent the number of sickle cell cases remains consistent generation after generation. ---- support the hypothesis.
In Canada the incident of sickle cell anemia has been increasing in the population. ----- contradicts the hypothesis.
Explanation:
In areas of Africa where malaria is widespread the number of sickle cell cases remains consistent generation after generation while on the other hand, In Canada the incident of sickle cell anemia are lower in the population because of environmental condition is not good for increase in malarial disease. In Africa, the environment is suitable for the mosquitoes that causes malaria so there is high increase of sickle cell anemia in the population.
