Biology 9 Lesson 19: Relationship between genes and traits
1. Theoretical Summary
1.1. What is the relationship between RNA and protein?
-mRNA is the intermediate form in the relationship between genes and proteins.
-mRNA is responsible for conveying information about the structure of the protein that is about to be synthesized from the nucleus to the cytoplasm.
– Formation of aa chain:
- The mRNA leaves the nucleus to the cytoplasm to synthesize the aa strand.
- The tRNAs are attached to 1 aa at one end, and the other end carries a set of three countercodes to the ribosome that matches the mRNA according to the A-U complementarity principle; G-X.
- When the ribosome moves 1 step on the mRNA (each step corresponds to 3 nucleotides), 1 aa is assembled into the aa chain.
- When the ribosome has moved the entire length of the mRNA, the aa strand is complete.
– The principle of forming chain aa:
- Based on the mRNA template and on the principle of A – U complement; G – X at the same time every 3 nucleotides corresponds to 1 aa.
- The nucleotide sequence on the mRNA determines the sequence of the aa on the protein.
1.2. Relationship between genes and traits
– Gene (a piece of DNA) → mRNA → Protein → Trait
- Gene is the template for the synthesis of mRNA.
- mRNA is the template for synthesizing the aa chain that makes up a protein.
- Proteins represent body traits.
– Nature of gene relationship → trait:
– The sequence of nucleotides in DNA (genes) determines the sequence of nucleotides in the mRNA, thereby determining the sequence of aa to make a protein. Proteins participate in the structure, physiological activities of cells and expression into traits.
2. Illustrated exercise
Describe the relationship between DNA, RNA, and proteins
Between RNA and genes, there is a relationship between genes and proteins: DNA is the template for RNA synthesis, RNA is the template for synthesizing amino acid chains to form proteins of the body. Proteins are directly expressed as traits of the organism.
3.1. Essay exercises
Question 1: How is NTBS represented in the new relationship in the diagram below?
Verse 2: Describe the nature of the relationship between genes and traits through the diagram:
Gene (a piece of DNA) → mRNA → Protein → Trait
Question 3: Compare DNA and proteins in terms of structure and function.
Question 4: What is the building block of a protein? List the functions of proteins.
3.2. Multiple choice exercises
Question 1: During protein synthesis, the A of the mRNA binds to?
A.T of tRNA
B. U of tRNA
C.G of tRNA
D.X of tRNA
Verse 2: What are the principles of amino acid chain synthesis?
D. Includes A and C
Question 3: A gene with 3000 nucleotides performs the synthesis of mRNA and then continues to synthesize proteins. What is the number of amino acids in the primary structure of a protein?
Question 4: If a gene has a length of 5100 A0, how many amino acids does the complete protein synthesized from the template of that gene have?
A. 497 amino acids
B. 498 amino acids
C. 499 amino acids
D. 500 amino acids
Question 5: Which of the following is not directly involved in the translation process?
After completing this lesson, you should:
- Understand the relationship between RNA and protein.
- State the relationship between genes and traits through the diagram: Gene → mRNA → Protein → Trait.