The variations might help the organism to survive if there is a change in its environment
Eg heat resistant bacteria
The variation might help the organism survive predators
Eg. Green beetles blend with green leaves thus disabling crows to spot them
:)
<span>Complementary base-pair rule.</span>
The nervous system is the major controlling, regulatory, and communicating system in the body. It is the center of all mental activity including thought, learning, and memory. Together with the endocrine system, the nervous system is responsible for regulating and maintaining homeostasis.
Answer:
DNA is a double helix and has base-pairing between nucleotides through the use of hydrogen bonds
Explanation:
The nucleotides are made up of a nitrogen base [base-pairing adenine (A) with thymine (T) and guanine (G) with cytosine (C)], a phosphate, and a deoxyribose (sugar); all of which are held together by hydrogen bonds. The binding allows the DNA to have a sugar-phosphate backbone connected with hydrogen bonds because they are firm but also easy to break (for DNA transcription)