Answer:
10%
Explanation:
Chargaff postulated the complementary base pairing rule, where he stated that in the DNA molecule, Adenine (A) will always pair with Thymine (T) and Guanine (G) with Cytosine (C) i.e. A-T, G-C
Chargaff stated that the concentration of purines (Adenine and Guanine) is always equal to that of pyrimidines (Thymine and Cytosine) i.e. {A} + {G} = {C} + {T}
These equal concentration equals 100% in totality i.e. A+G+C+T= 100%
Thymine pairs with Adenine, if there is 40% of Thymine in the DNA molecule, it means there will be 40% of Adenine also. 40 + 40 = 80%. This leaves us with 100-80 = 20% for Guanine and Cytosine.
Since there will be an equal amount of Guanine and Cytosine too, Guanine will therefore, be 20/2 = 10%.
That is, 10% Guanine, 10% Cytosine.
.............................Correct.
Magnetic force - B.
Electrical force - A.
Gravitational force - D.
Contact force - C.
<h3><u>Explanation:</u></h3>
When a charge moves about its path, it produces a magnetic force around it. This magnetic field is perpendicular to the axis of movement of the charge and is directly proportional to the amount of charge, speed of the charge, and inversely proportional to distance between the charge and the point of measurement. Michael Faraday discovered this phenomenon.
Electrical force of attraction or repulsion is seen between the two charged bodies, or one charged body and one uncharged body which can induce charge to the uncharged body. The attraction or repulsion between the charged bodies are seen if the bodies are close enough, and this is called electrical force.
The gravitational force is also a non contact force that is seen between two bodies which is always attractive in nature and is seen between any two bodies.
A contact force like friction is a type of force that takes place only when two bodies are in contact with each other.
Considering the following;
I. Heat is not readily available to all living cells.
II. Heat at excessive amounts denatures proteins.
III. Heat does not provide the activation energy for their reactions.
IV. When a critical temperature is reached, proteins no longer function
Answer;
I and IV
Explanation;
Living cells cannot use heat to provide the activation energy for biochemical reactions because heat is not readily available to all living cells and also when a critical temperature is reached, proteins no longer function.
Too much heat can kill an organism by rendering its organelles, cells, tissues and organs permanently inoperable and un-salvageable. The same process can be observed in tissues at low temperatures, and is the cause of frostbite. This is because enzymes are denatured by high temperature and inactivated by low.
Answer:
respiration, waste production, food intake, cells, breathing
