Answer:
Troponin and calcium ions.
Explanation:
Troponin is a component of thin filament along with tropomyosin and actin. It is a protein complex to which calcium binds and start the production of muscular force.
Calcium also playing a very important role in muscle contractions, it binds with troponin and helping to move tropomyosin.
When calcium ion attached to troponin, then conformational changes occurs in troponin shape and moves which allow tropomyosin going away from its inhibitory position from the myosin-binding sites on actin. After this, the energized myosin head starts binding to the actin molecules and starts the cross bridge cycle, which helping in shortening the muscle's fiber.
I think it is A . eubacteria
Oparin and Haldane's theory and Miller's experiment are the proof that long complex molecules that carry information such as DNA, might have formed on early earth.
Explanation:
Oparin and Haldane Hypothesis states that life on Early earth could have evolved by chemical evolution.
Oparin and Haldane said that the reducing atmosphere of the early earth caused simple inorganic molecules to react by using sunlight and formed molecules like amino acids and nucleotides.
These monomers combined to form polymers, they would have attained self-replicating tendency eventually these would have assembled into structures and these macromolecules had also made membrane-bound organelle.
Although this hypothesis is not fully accepted but part of it which talks about formation of molecules is accepted.
Millers and Urey in their experiment created an artificial reducing environment like that of early earth. They used a heated pool of water, atmospheric gases like H2O,CH4,N2, NH4 and sparks of electricity. After running the experiment for some days they found that amino acids, sugars, lipids and other organic molecules had formed.
Their hypothesis is not fully accepted but part of is evident that organic building block is formed from inorganic constituent on the earth.
