Adenine which is a purine base, always pairs with the pyrimidine Thymine in DNA and Uracil(also a pyrimidine) in RNA. The bond which is present between the two bases is a double hydrogen bond.
Guanine which is also a purine base, always pairs with the pyrimidine Cytosine, in the case of both, DNA and RNA. The bond which is present between the two bases is a triple hydrogen bond and hence, is stronger than the A-G double bond.
The more numbers of the homologous structure, the more likely they have recently shared a common ancestor.
Explanation:
Homologous organs are defined as those organs which do have different functions but a similar basic structure which denotes the divergent evolution. Homologous organs are seen in species that are very close to each other which are more related with each other in terms of evolution. For example, a bird is more close to each man than a fish, so do share more homologous organs common to man than fishes do. Examples of the homologous organs are hands of human and wings of birds. They have same basic structure like skeletal structure which is humerus, radius, ulna, carpals, metacarpals and phalanges. They are similar in structure but have different functions like flying in birds and gathering food in humans.
d bc (a b c and d) r the same to make a tidepool
The correct answer is option C, that is, the Operons afford the organism the opportunity to simultaneously monitor the transcription of multiple genes, whose products are active in the same process.
The genes, which correspond to a particular metabolic procedure are usually under the control of a single promoter in a bacteria. This is known as Operon that assists in monitoring the expression of genes taking part in the similar metabolic procedure.