Transport proteins (carrier proteins and channel proteins) allow substances into and out of the cell that cannot pass through the phospholipid bilayer (as they’re either to large, charged or not lipid soluble) by facilitated diffusion.
Specifically channel proteins allow ions into and out of the cell by creating a pore in the membrane in which they can move through with their concentration gradient
Global warming causes increase level CO2
Complex molecules are made up of other elements bonded with carbon. Carbon is able to bond with other molecules so easily because it has four valence electrons.
Answer:
The correct answer will be-
1. Observation-option B.
2. Hypothesis-option A.
3. Experiments- option C.
Explanation:
A scientific method involves various steps to explain a natural phenomenon of nature. It begins with making an observation which leads to asking the scientific question. The researcher does background research and proposes a hypothesis which could be tested through experiments. The experiments could prove or disprove the hypothesis based on the results.
In the given question the observation made is an equal amount of A and T and G and C are observed. It leads to a hypothesis which shows that this could have happened due to the winding of two strands of DNA and the experiments was performed through X-ray diffraction pattern.
Thus, the selected options are the correct answer.
