THE MOLECULAR BASIS OF INHERITANCE
STRUCTURE OF NUCLEIC ACIDS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
1
|
|
|
2
|
|
|
3
|
|
|
4
|
Detailed explanation-1: -The size of RNA molecules depends on the type. tRNA molecules range from 60 to 95 nucleotides, some rRNA molecules in E. coli have polynucleotide strands of 120, 1500, and 2900 nucleotide units, while mRNA ranges from hundreds to thousands of nucleotides.
Detailed explanation-2: -DNA contains two complementary nucleotide chains and forms a structure known as the double-helix as these two chains are wrapped around each other. On the other hand, RNA typically contains a single chain of nucleotides, transcribed from one of the DNA chains.
Detailed explanation-3: -A DNA molecule consists of two long polynucleotide chains composed of four types of nucleotide subunits. Each of these chains is known as a DNA chain, or a DNA strand. Hydrogen bonds between the base portions of the nucleotides hold the two chains together (Figure 4-3).
Detailed explanation-4: -A tRNA, like the one modeled below, is made from a single strand of RNA (just like an mRNA is). However, the strand takes on a complex 3D structure because base pairs form between nucleotides in different parts of the molecule. This makes double-stranded regions and loops, folding the tRNA into an L shape.