Questions

The letter 'W' is at the end of a rainbow.

Nominal money relates more to it's measure of counting - so nominal figure of what is written on bill, while "real" relates more to it's purchasing power (usually between some periods of time). For instance 100 units in nominal could buy 2 units of good in 1950 and 1 unit of good in 2005, at the same time real value of this 100 nominal units are 100 real units in 1950 and 50 real units in 2005.

Same is with GDP. In nominal it can rise due to inflation while it can stay the same or even decrease in real value.

Amino acids are the building blocks of proteins. There are about 21 essential amino acids in the human body like histidine, leucine, lysine... The general formula for amino acid is R-CH(NH2)-COOH.

A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function.

Hence, Cells with similar markers stick together and function as tissues.

One of two sublayers of the data link layer of OSI reference model, as defined by the IEEE 802 standard. This sublayer is responsible for maintaining the link between computers when they are sending data across the physical network connection

Osmosis is the process in which water molecules move from a region of higher water potential to a region of lower potential down a water potential gradient across a partially permeable membrane. It doen't requires any additional energy to do this work. 

So, Osmosis is a Passive.

Active and passive transport processes are two ways molecules and other materials move in and out of cells and cross intracellular membranes.

1. Active transport is the movement of molecules or ions against a concentration gradient (from an area of lower to higher concentration), which does not ordinarily occur, so enzymes and energy are required.

2. Passive transport is the movement of molecules or ions from an area of higher to lower concentration. Passive transport occurs because of the entropy of the system, so additional energy isn't required for it to occur.

3. Active transport requires energy to proceed, while passive transport does not require the input of extra energy to occur.