Question

1. describe how is dna related to chromosomes?
2. identify relationships how are proteins involved in dna replication?
3. list what are three parts of a nucleotide?

Explanation:

4. DNA and Chromosomes

Chromosomes are structures within cells that contain DNA. DNA is the genetic material that holds the instructions for the development, functioning, and reproduction of living organisms. Chromosomes are made up of DNA tightly coiled around proteins called histones.

5. Proteins in DNA Replication

• Helicase: Unwinds the double - stranded DNA by breaking the hydrogen bonds between the base pairs.
• Primase: Synthesizes short RNA primers. These primers provide a starting point for DNA polymerase to begin adding nucleotides.
• DNA polymerase: Adds complementary nucleotides to the growing DNA strand. There are different types of DNA polymerases, with DNA polymerase III (in bacteria) being the main enzyme for adding nucleotides during elongation.
• Ligase: Joins the Okazaki fragments (short DNA segments on the lagging strand) together by forming phosphodiester bonds.

6. Parts of a Nucleotide

A nucleotide is the basic building block of nucleic acids (DNA and RNA). It consists of three parts:

• Nitrogenous base: In DNA, the nitrogenous bases are adenine (A), thymine (T), cytosine (C), and guanine (G). In RNA, thymine is replaced by uracil (U).
• Pentose sugar: In DNA, it is deoxyribose; in RNA, it is ribose.
• Phosphate group: One or more phosphate groups are attached to the sugar. In a nucleic acid strand, nucleotides are linked together by phosphodiester bonds between the phosphate group of one nucleotide and the sugar of the next nucleotide.

Answer:

1. Chromosomes are made of DNA coiled around histones.
2. Helicase unwinds DNA, primase makes RNA primers, DNA polymerase adds nucleotides, ligase joins fragments.
3. Nitrogenous base, pentose sugar, phosphate group.