Answer

Across:8. Histones9. DNA replication12. Mutations13. Frameshift15. Transcription16. Point mutationDown:1. rRNA2. Histones3. Nucleotide4. DNA polymerase5. Genes6. tRNA7. Chargaff's rule10. Codons11. Translation14. mRNA

Explanation

This crossword puzzle is related to the structure and function of DNA and its role in protein synthesis. The answers to the clues are based on fundamental concepts in molecular biology. Let's go through each clue and provide the appropriate term.Across:8. Proteins that DNA coils around: These are called histones. Histones are proteins that DNA wraps around, forming a structure known as a nucleosome.9. The duplication of DNA: This process is known as DNA replication. It is the process by which a cell duplicates its DNA before cell division.12. Changes in genetic material: These are referred to as mutations. Mutations can occur in the DNA sequence and can lead to changes in the organism's traits.13. A mutation that adds or deletes a nucleotide thus shifting the "reading frame" of the genetic message: This is known as a frameshift mutation. It can have significant effects on the resulting protein.15. The process of producing RNA molecules by copying a portion of DNA into a complementary RNA sequence: This process is called transcription. It is the first step in gene expression.16. A mutation that changes a nucleotide at a single point: This is known as a point mutation or a substitution. It can result in a change in the amino acid sequence of a protein.Down:1. Ribosomes are made up of this kind of RNA: Ribosomal RNA (rRNA) is the type of RNA that, along with proteins, makes up ribosomes.2. DNA tightly coiled around proteins: As mentioned earlier, this is referring to histones.3. The unit that makes up a DNA molecule: The basic unit of DNA is the nucleotide, which consists of a sugar, a phosphate group, and a nitrogenous base.4. Enzyme involved in DNA replication: DNA polymerase is the enzyme responsible for adding nucleotides to a growing DNA strand during replication.5. Coded DNA instructions that help control the production of proteins within the cell: These are called genes. Genes contain the instructions for making proteins.6. RNA that carries the amino acids to the ribosome: Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosome during protein synthesis.7. The principle stating that hydrogen bonds can only form between adenine and thymine and guanine and cytosine: This is known as Chargaff's rule.10. Three consecutive nucleotides that specify a single amino acid to be added to the protein: These are called codons. Each codon corresponds to a specific amino acid.11. The decoding of an mRNA message into a protein: This process is called translation. It is the second step in gene expression, where the mRNA is read by ribosomes to produce a protein.14. RNA molecules that carry copies of genes: These are called messenger RNA (mRNA). mRNA carries the genetic information from DNA to the ribosome, where it is translated into a protein.