a ecosystem refer to a river
Answer: C) The benthic invertebrates would decrease in population size because they are eaten by the sea ducks and the phytoplankton would increase in population size.
Explanation:
The benthic invertebrates are eaten by sea ducks. Sea ducks are eaten by bald eagles. If the bald eagle was removed, there would be more sea ducks because they will have no more predators. Since there are more sea ducks, they will need to eat more food, like benthic invertebrates. The benthic invertebrates would have a lower population because the sea ducks eat more of them.
Why not the other answers:
A) The bivalves would not increase in population size. Without the bald eagle preying on sea ducks, there would be more sea ducks, who need to eat more food, such as eating more bivalves.
The phytoplankton would not decrease. With sea ducks eating more food, more benthic invertebrates are eaten. There would be less benthic invertebrates to eat phytoplankton.
B) Tundra swans were never eaten by bald eagles. There is no arrow connecting them.
D) Wading birds were never eaten by ospreys. There is no arrow connecting them.
Explanation:
The correct answer among the options given is the last option. Fossil fuels are the resources that cannot be renewed. Resources that cannot be renewed or replenished are referred as non-renewable resources. Fossil fuels are made for very long periods of time and cannot be replenished instantly.
I believe the correct answer is mRNA. Dicer is a part of RNase III which leaves double stranded RNA and pre-microRNA into short double stranded RNA fragments called small interfering RNA and microRNA respectively. The Dicer facilitates the activation of RNA induced silencing complex (RISC), which are essential for RNA interference. The RISC has a catalytic component argonate, which is an endonuclease capable of degrading mRNA. siRNAs are specfic to the mRNA sequence unlike miRNAs which are not completely complementary to the mRNA sequence.