C.
Every change in a species is coded within the DNA. But the bird had lost a toe an accident. So the toe-loosing-option isn't true because not every bird looses his toe.
(Example: If a women gets bitten by a snake on the arm and gets the arm removed from her body and then in a year or so has a baby with her new husband. The baby won't be born with one arm because his/her mother lost her arm.) <span />
Phosphate groups of the nucleotides in the diagram are marked with W.
Option C.
<h3><u>Explanation:</u></h3>
DNA is a macro molecule which is formed of polymerization of deoxyribonucleotides. Four types of deoxyribonucleotides are present which are adenosine, guanosine, thymidine and cytosine triphosphate. These nucleotides are polymerized based on the genetic setup.
The phosphate groups attached with the sugar molecule are actually polymerized with the o glycosidic bond. That's marked with the letter W. These phosphate molecules are attached with the sugar molecules which actually are attached with the nitrogen bases. They in total forms a nucleotide, hence the whole DNA. X in the diagram are nitrogen bases and the Y are the hydrogen bonds between the complementary nitrogen bases
Answer: Farming
Explanation: Plowing the land is the first source of wealth.
1. The answer is "<span>the energy required to start the reaction".
</span>This energy is called as activation energy of the reaction. If the activation
energy is high, reaction is slow. Enzymes help to carry out the reaction by
a new path by reducing the activation energy. But the energy of reactants
and the products remain as same as without enzyme.
2. The answer is "reaction in cells would be too slow to sustain life<span>".
</span>If the activation energy is very high for the reaction, then that reaction will
be very slow and will require more time<span> to complete the reaction. Then survival is
very low. Hence, the roll of enzymes is very important to sustain life.</span>
Answer: B
Explanation:
That question lets you know how the pet is living on a daily basis. The other answer choices ask about medical history, but B asks about environment.