Hydrophobic is when it cannot dissolve in water and hydrophilic is when it can. an example is a phospholipid in the cell membrane- the the tails are hydrophobic and the heads are hydrophilic.
Excitation-contraction coupling refers to the series of events that begins with the excitation of the sarcolemma in response to stimulation by a neurotransmitter, and results in the release of calcium ions from the sarcoplasmic reticulum.
Hence, option D is the 1st process that starts the excitation-contraction coupling.
Answer: Liver
Explanation:
The hepatic portal system of liver connects the capillaries of the gastrointestinal tract to the liver. The nutrient rich blood from the gastrointestinal tract reaches the liver.
The blood that is returned back to the heart is first bought to liver and then it is returned back to the heart.
From the liver after processing the blood goes into heart for further processing.
Hence, the correct answer is option d
<span>The mountains were once seas. The land was forced up by tectonic motion when the mountains were formed. The Sahara also used to be a sea and has a valley full of the fossilized remains of an extinct species of whale. It is generally agreed upon that two plates colliding caused the uplift that created the mountainous zone. Same for the Himalayas.</span>
The answer is 4Fe+3O2→2Fe2O3
