A single ringed nitrogeo base is thymine (C)
This attracts bees which, when collecting the nectar, they carry residue pollen on the flower to the next flower, which then pollinates the flowers, hence allowing them to asexually reproduce.
Answer:
a. 342.9 kJ of heat are absorbed.
Explanation:
Calculation of the moles of 
as:-
Mass = 20.00 g
Molar mass of = 17.031 g/mol
The formula for the calculation of moles is shown below:
Thus,
Given that:- 
It means that 1 mole of undergoes reaction and absorbs 1168\ kJ of heat
So,
1168 mole of undergoes reaction and absorbs 
of heat
<u>Amount of heat absorbed = + 342.9 KJ</u>
Answer: The compound in medicines should be non polar.
It is important for any drug to be able to dissolve itself through the cell membrane which consists of a lipid bi-layer, in order to diffuse in the body and circulate biologically, performing its function.
Non polar compounds are lipid soluble and therefore can dissolve in the lipid layers.
Polar compounds are water soluble and fail to cross the cell membrane.
Therefore scientists need to be sure of using compounds that are non polar in nature so they pass through the cell membrane and enter into the blood circulation of the body and perform its due function.
Explanation:
