Answer:
C
Explanation:
The damage to DNA usually occurs where there are two consecutive thymine nucleotides on a DNA strand. The energy from the UV light causes the two dimers to form a cyclobutane pyrimidine structure. Proofreading and repair mechanism of DNA find it difficult to repair this kind of damage on DNA. During replication, therefore, DNA polymerase is unable to replicate this region hence leading to a mutation on the replicated strand at this local point.
A temperature of absolute zero is the point at which the gas particles stop moving. This corresponds to a temperature of . Particles have no kinetic energy at all so no energy can be removed and the temperature cannot get any lower. With no kinetic energy and now stationary, the particles will exert no pressure either.
<h2>Vasa recta </h2>
Explanation:
The vasa recta is a specialized capillary that branches from the efferent arteriole; The blood flow in the vasa recta runs parallel, but in the opposite direction to the flow of tubular filtrate within the nephron loop
- The vasa recta capillaries are long, hairpin-shaped blood vessels that run parallel to the loops of Henle
- The hairpin turns slow the rate of blood flow, which helps maintain the osmotic gradient required for water reabsorption
- Absorbed water is returned to the circulatory system via the vasa recta, which surrounds the tips of the loops of Henle
- Because the blood flow through these capillaries is very slow, any solutes that are reabsorbed into the bloodstream have time to diffuse back into the interstitial fluid, which maintains the solute concentration gradient in the medulla; this passive process is known as counter-current exchange
