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DNA replication is the essential biological process of producing two identical replicas of DNA from one original DNA molecule, occurring in all living organisms prior to cell division.

If the percentage of adenine (A) in human DNA is 32%, the percentage of thymine (T) would also be 32%. This calculation is based on Chargaff's rules, which state that in a double-stranded DNA molecule, nitrogenous bases always pair in a specific manner: Adenine (A) always pairs with Thymine (T) (A = T). Guanine (G) always pairs with Cytosine (C) (G = C)

Both statements in options B and C are not correct based on the biological principles of sex-linked inheritance: Males cannot be carriers: Because colour blindness is an X-linked recessive trait and males have only one X chromosome, they will always express the condition if they possess the gene. They cannot "carry" it without being affected. Females can be carriers: Females have two X chromosomes. If they have the gene on only one of these chromosomes, they do not express the condition but can pass it to their offspring.

Lamarck's theory, also known as Lamarckism or the inheritance of acquired characteristics, posits that physical changes an organism undergoes during its lifetime—such as the development of an organ through increased use or its weakening through disuse—can be passed directly to its offspring. He famously used the example of giraffes stretching their necks to reach high leaves, suggesting this stretching resulted in longer necks that were then inherited by the next generation.

The theory of natural selection was formulated by Charles Darwin, who independently reached the same conclusion.

\(\overline{MN} || \overline{KL}\), \(\triangle\) LXK is similar to \(\triangle\)MXN So, the ratio of the areas of the two similar triangles equals the square of the ratio of their corresponding sides Therefore, \(\frac{ Area of \triangle MXN}{Area of \triangle LXK} = \frac{12^2}{9^2}\) \(\frac{16}{Area of \triangle LXK} = \frac{144}{81}\) Area of \(\triangle\)LXK = \(\frac{ 16 \times 81}{144} = 9cm^2\)

(a) A thermometric liquid is a liquid used in thermometers to measure temperature. It expands and contracts uniformly with changes in temperature, allowing for accurate readings. (ii) I. Narrow Bore Reason: Allows precise measurement by controlling the movement of the thermometric liquid, ensuring quick and accurate readings II. Thin Wall of the Bulb Reason: Enhances thermal conductivity, enabling faster heat transfer for quicker and more accurate temperature readings. (b) Heat is a measure of the change in total internal energy in a body while temperature is a measure of the average kinetic energy of a molecule of the body. (c) Evaporation leads to cooling for these reasons: Energy Absorption: Molecules at the surface absorb energy to break free, often from the liquid and its surroundings. Loss of High-Energy Molecules: Higher-energy molecules evaporate, reducing the average kinetic energy of the remaining liquid. Temperature Decrease: As the average kinetic energy drops, the temperature of the liquid decreases, resulting in cooling. (d)(i) Given: P = 2000W, \(\theta\) = 20ºC, t = 2 mins = 120 secs. P x t = mc\(\Delta\)\(\theta\) m = \(\frac{P \times t}{c \times \Delta \theta}\) m = \(\frac{2000 \times 120}{4200 \times (100 - 20)}\) = 0.714 kg Also, Pt = ml l = \(\frac{Pt}{m}\) where m = 45% of 0.714, t = 6mins = 360secs l = \(\frac{2000 \times 60 \times 6}{0.714 \times 0.45}\) = 2.29 x 10\(^6\)Jkg\(^{-1}\) (d)(i) Assumption made: there is no loss of heat to the surroundings, and the heat capacity of the material of the kettle is negligible.

The maximum displacement of particles from equilibrium position in a wave motion is known as "amplitude".

(a) The uses of polar satellites include: (i) for location identification (ii) to collect data on climate change (iii) observe and predict a natural disaster (iv) use for communication. (b) The slope of a graph of tensile stress against tensile strain represents the modulus of elasticity, also known as Young's modulus. Young's modulus quantifies the stiffness of a material. A steeper slope indicates a stiffer material, while a flatter slope indicates a more flexible material.

At the maximum height, all the kinetic energy will have been converted into potential energy: mgh = \(\frac{1}{2}\)mv\(^2\) v = y gh = \(\frac{1}{2}\)y\(^2\) h = \(\frac{y^2}{2g}\) Thus, the potential energy will be maximum at the height given by: \(\frac{y^2}{2g}\)

The magnitude of the acceleration of a moving object is equal to the rate of change of its velocity over time. Gradient of a velocity-time graph refers to the slope of the graph that plots velocity (y-axis) against time (x-axis).

The total area under the entire segment from P to R (the area of the triangle plus the area of the rectangle) represents the total distance traveled by the cyclist during the motion from P to R.

A body moves with uniform velocity when there is no acceleration. According to Newton's first law of motion, an object will remain in its state of rest or uniform motion unless acted upon by a net external force.Therefore, if the resultant force acting on the body is equal to zero, it will maintain a constant velocity, which means it can be moving at a constant speed in a straight line.

Total mass of the two boxes = 27.3 + 6.2 = 33.5kg F = ma a = \(\frac{\text{F}}{\text{m}}\) = \(\frac{150}{33.5}\) = 4.4776... ≈ 4.5 ms\(^{-2}\)

(a)i c = 50.0cm (ii) M\(_R\) = 90.0 g (vii) d = 0.8m (ix) S/N h(cm) t(s) T= \(\frac{t}{20}\)s T\(^2\)s\(^2\) 1 40.0 26.12 1.306 1.7056 2 50.0 27.80 1.390 1.9321 3 60.0 30.68 1.534 2.3532 4 70.0 34.60 1.730 2.9929 5 80.0 35.80 1.790 3.2041 (x) SEE THE GRAPH ABOVE (xi) Slope, s = \(\frac{\DeltaT^2}{\Delta h}\) = \(\frac{3.0 - 1.75}{75 - 46}\) = \(\frac{1.25}{29}\) = 0.431s\(^2\)cm\(^{-1}\) (xii) K = \(\frac{\text{S}}{\text{Q}}\) where, Q = \(\frac{2}{25d^2}\) = \(\frac{2}{25 \times (0.8)^2}\) = 0.125 K = \(\frac{\text{S}}{\text{Q}}\) = \(\frac{0.431}{0.125}\) = 0.3448 b(i) A couple, as related to oscillatory motion, refers to a pair of forces that are equal in magnitude but opposite in direction, and act on opposite sides of a pivot or fulcrum, causing rotation or torsion. b(ii) I. Wrenches: When using a wrench to tighten or loosen a bolt, the force applied creates a couple that produces rotational motion. II. Steering Wheels: Turning the steering wheel of a car applies a couple that rotates the front wheels, allowing for directional change. III. Door Handles: When pushing or pulling on one side of a door handle, a couple is created that rotates the door about its hinges. IV. Bicycle Pedals: When pedaling a bicycle, the force applied to the pedals generates a couple that turns the crankshaft, propelling the bike forward.