Answer:
A: light availability
B: nutrients
Explanation:
Both nutrients and light availability affect the primary productivity of the freshwater ecosystem, therefore, scientists study both factors to track associated changes. This is because photosynthesis is driven by sunlight and nutrients availability. It is suggested that the abundance of autotrophs (e.g. phytoplanktons) in an aquatic ecosystem increases as light and nutrients availability increase. Thus, there will be more food available for secondary and tertiary consumers to feed upon. Resultantly, the aquatic environment will turn a biodiversity hotspot where many species of living organisms start dwelling. Thus, scientists mainly ecologists would focus on these two parameters at first that lead to consideration of other parameters.
For more information, you may want to read this scholarly article
https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.4319/lo.2006.51.1.0288
1 C. 2. b 3,A 4A hope this helpps
Its either dead material or organisms that eat producers
The correct answer is "neurons".
Neurons are nerve cells which connect to each other using synapses and form neural networks. They exhibit high levels of specialization and are the primary components of the central nervous system.
Myofibrils are contractile fibers which form the striated muscle cells. Sarcomeres are the structural unit of the myofibrils.
