Question

with the help of following pattern briefly explain the reason for 1) dna stability 2) variation phenomenon found in successive generation of species

Answer 1

Evolution is defined as the descend with modification.

1. DNA STABILITY: DNA is double helical structure. this  structure give DNA the stability. this stability is necessary as it prevent the damaging and breaking of DNA strand.
2. VARIATION PHENOMENON:  sexual reproduction and crossing over brings variation in successive generation of species. and those with variation are more stable and have more power of adaptability.

Answer 2

DNA (deoxyribonucleic acid) is more stable compared to RNA (ribonucleic acid) because of its conformation in double-stranded form and the absence of the -OH function in position 2 of sugar. The DNA has 2-deoxyribose while the RNA has ribose.

The DNA undergoes, over time, mutations, ie changes in its nucleotide sequence. And since DNA is inherited across generations, we can observe these variations of sequence over generations.