Explain which planets have seasons and why some planets have none at all.

Earth is the planet that has seasons but the rest do not

Explanation:

Earth's axis is tilted 23.5 degrees, but Venus is only tilted 3 degrees. This lack of tilt means the planet's surfaces receive a uniform amount of the Sun's energy. Though Venus has seasons, there is little change from one to the next. Venus also has a much shorter orbit than Earth, making its seasons very brief.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.