Answer:
See Explanation
Explanation:
The question is incomplete as the diameters of the Willapa Bay urchins were not given.
However, I'll give a general way to solve this problem.
Average is calculated using:

i.e. Sum of all diameters divided by the number of bay urchins.
The diameter of urchins is usually between 6cm to 12cm; So, I will assume the following diameters for 10 urchins.
10cm, 8cm, 10cm, 7cm, 9cm, 10cm, 6cm, 10cm,8cm, 8cm
Using the above data, the average is:



Answer;
-Noble gases or Group 18 elements
Explanation;
A full valence shell is the most stable electron configuration. Group 18 elements or noble gases such as helium, neon, and argon, have a full outer, or valence, shell. Elements in other groups have partially-filled valence shells and gain or lose electrons to achieve a stable electron configuration.
They are extremely unreactive and do not form bonds with themselves. Solid helium is the the ultimate fine powder being monotomic.
It happens in glycolysis. It gets broken down into two pyruvates and it happens in the cytoplasm.
Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
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Explanation:
Solutes are typically moved across the cell through either passive or active transport. The cells, surrounded by a bilipid layer or plasma membrane is amphiphlic- its polar, hydrophilic lipid heads face outwards, while their non-polar hydrophobic lipid tails face inwards towards each other.
While lipid-soluble molecules move across the layer easily, it is also difficult for charged and also large molecules to move across its surface, into the cell. Transmembrane channels, <u>embedded within the membrane</u>, help to maintain selective permeability as transport proteins, pores and gated channels. Simple diffusion happens as a method of passive transport in cells through plasma membranes.
The solutes travel through the plasma membrane in the process of diffusion from regions of high concentration to regions of low concentration; this occurs without the use of energy. <u>Molecules moving against their concentration require active transport mechanism to cross the membrane</u>.