The solutions would be a, b, e, f.
When a muscle cell contracts some myosin heads bind to actin molecules as other myosin heads release from actin molecules.
Muscle contraction occurs when the thick filament and the thin filaments slide over one another in a series of repetitive events.
The same way humans do:
By breathing in oxygen and then it goes into the system and filters through and they get CO2 as a waste product just like us!
Hypothesis.
A Hypothesis is an estimation of what might happen and the student's observation before moving on to investigate.
Greenhouse gases arise naturally, and are part of the make-up of our atmosphere. Earths conditions are just right to allow life, including us, to flourish. Part of what makes Earth so amenable is the naturally-arising greenhouse effect, which keeps the planet at a friendly 15 °C (59 °F) on average. But in the last century or so, humans have been interfering with the energy balance of the planet, mainly through the burning of fossil fuels that give off additional carbon dioxide into the air. The level of carbon dioxide in Earth’s atmosphere has been rising consistently for decades and traps extra heat near the surface of the Earth, causing temperatures to rise.