B. One
because an independent variable is something you change. So in a scientific experiment you only change one thing. If you happen to change more than one thing then the test becomes unfair therefore you should repeat and make sure that only one thing is changed this time.
The answer is option B "declining number and variety of the species in an area." Biodiversity is a variety of life for example a ecosystem has many species which makes it a biodiversity. Now a loss of a biodiversity would be loosing a huge amount of species in that area or ecosystem which would mean the answer is option B.
Hope this helps.
Both of them produce mucus.
Answer:
Animals preserve play very important role in maintaining ecosystem biodiversity. In animal preserves, animals are protected from the harmful effects of the changes which occur in the environments due to human intervention. In animal preserves,
animals should be kept in proper environment and provide a proper place for living and food in order to increase the population of the animals.
Mutualism is when both sides benefit. The hummingbird gets nectar and the flower is benefited because the hummingbird that has been to other flowers carry pollen on its body which spread the flower when it sucks its nectar, therefore pollinating the flower in the process.
