D. The remains of living things
Fossils are the remains of living things
Answer:
Option). It permits hydrogen bonds between DNA strands to dissociate.
Explanation:
PCR (polymerase chain reaction) techniques can bed defined as a technique, which is used for in vitro amplification of sample DNA. It is made up of three steps, denaturation, primer annealing, and extension.
The first step in PCR is heating of sample DNA to denature the double stranded DNA by breaking hydrogen bonding present between bases of double stranded DNA.
Due to this, double strands of DNA get separated and provide templates for synthesis of daughter DNA strands.
Thus, the correct answer is second option.
The original source of energy in a food chain is the sun.
Answer:
Vacuum
Explanation:
A vacuum is usually defined as a space in which there is an absence of matter. It can also be said that there is an extremely low amount of pressure due to which the particles present in it are not affected by any type of process that occurs in space. The value of pressure is lower than the value of normal atmospheric pressure.
For example, sound cannot travel in space because there is no medium such as water and air through which the sound waves can propagate.
