Answer: The correct answer is 3) A segment of a DNA molecule that contains the instructions for producing a trait in an organism.
Gene is a segment of DNA molecule that contains instructions ( in the form of nucleotide sequences), which are required for producing a specific trait ( characteristic) of an organism.
For this, gene is first transcribed into mRNA ( messenger RNA), which is then translated to produce a particular protein. The protein thus formed gives a specific characteristic to the organism.
Thus, option 3) is the best description for a gene.
They use their skin to do gas exchange
Answer:
B. The ddNTPs lack a 3′ hydroxyl group.
Explanation:
Dideoxynucleotides is a family of inhibitors of the DNA polymerase, its official name is 2',3' dideoxynucleotides but they are commonly called ddNTPs. One of the main characteristics of this compound is the absence of the 3'-hydroxyl group in the deoxyribose, due to the absence of this group, it is impossible to form a phosphodiester bond between nucleotides and the DNA synthesis is stopped.
Venus is the answer, you can tell easily because Venus has no moons or rings :)