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Answer parts (a), (b) and (c) of the question on pages 2–4 of the Section II Writing Booklet - HSC - SSCE Biology - Question 33 - 2013 - Paper 1
Question 33
Answer parts (a), (b) and (c) of the question on pages 2–4 of the Section II Writing Booklet. Start each part of the question on a new page. (a) Outline polygenic i... show full transcript
Worked Solution & Example Answer:Answer parts (a), (b) and (c) of the question on pages 2–4 of the Section II Writing Booklet - HSC - SSCE Biology - Question 33 - 2013 - Paper 1
Step 1
Outline polygenic inheritance. Include an example in your answer.
Answer
Polygenic inheritance refers to the phenomenon where multiple genes (often located on different chromosomes) contribute to a single trait or phenotype in an organism. This type of inheritance results in a continuous range of phenotypes, rather than discrete categories.
For example, human skin color is influenced by several genes, each contributing to the production of melanin. The combined effects of these genes produce a spectrum of skin tones, demonstrating how polygenic inheritance operates in a population.
Step 2
Outline how the structure Y enables information from DNA to be translated into a polypeptide.
Answer
The structure Y is likely referring to a ribosome, which plays a crucial role in the translation process of protein synthesis.
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mRNA Role: The messenger RNA (mRNA) carries the genetic code from the DNA, which is transcribed in the nucleus and transported to the ribosome.
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tRNA Interaction: Transfer RNA (tRNA) then interprets the mRNA sequence by matching specific amino acids to their corresponding codons on the mRNA.
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Peptide Bond Formation: The ribosome facilitates the binding of tRNA anticodons to the mRNA codons, allowing for the sequential addition of amino acids. This process ultimately leads to the formation of peptide bonds, resulting in the synthesis of a polypeptide.