Question

1. which nitrogen bases pair together in dna? 5. which base is found only in rna? 6. what is the \sugar - phosphate backbone\ in a nucleic acid? 7. why is dna referred to as the \code of life\? 8. how does rna contribute to protein synthesis? 9. explain how genetic information is inherited through dna.

Explanation:

1. In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G) through hydrogen - bonding.
2. Uracil (U) is the base found only in RNA. It replaces thymine in RNA.
3. The sugar - phosphate backbone in a nucleic acid is formed by alternating sugar (deoxyribose in DNA, ribose in RNA) and phosphate groups. Phosphodiester bonds link the 3' carbon of one sugar to the 5' carbon of the next sugar.
4. DNA is referred to as the "code of life" because it contains the genetic instructions for the development, functioning, growth, and reproduction of all living organisms. The sequence of nucleotides in DNA determines the sequence of amino acids in proteins, which carry out most of the cell's functions.
5. RNA contributes to protein synthesis in several ways. Messenger RNA (mRNA) carries the genetic code from DNA in the nucleus to the ribosomes in the cytoplasm. Transfer RNA (tRNA) brings the appropriate amino acids to the ribosome based on the codons on the mRNA. Ribosomal RNA (rRNA) is a component of the ribosomes, which are the sites of protein synthesis.
6. Genetic information is inherited through DNA because during cell division (mitosis and meiosis), DNA is replicated. The replicated DNA is then passed on to daughter cells. In sexual reproduction, the DNA from two parents combines during fertilization, and the offspring inherit a combination of genetic information from both parents.

Answer:

1. Adenine (A) pairs with thymine (T), cytosine (C) pairs with guanine (G).
2. Uracil (U).
3. Alternating sugar (deoxyribose in DNA, ribose in RNA) and phosphate groups linked by phosphodiester bonds.
4. It contains genetic instructions for life processes.
5. mRNA carries genetic code, tRNA brings amino - acids, rRNA is part of ribosomes.
6. DNA is replicated during cell division and passed to daughter cells; in sexual reproduction, parental DNA combines.