DNA, Genes and Principles of Heredity — O/L Science

How do I practise DNA, Genes and Principles of Heredity?

1 question with a worked solution · 6 marks

1. 2022 · Paper II · 6 marks
   Question 8 states that in pea plants the tall allele is dominant over the short allele. It asks you to write the genotype and phenotype of a homozygous tall plant, to use a Punnett square to predict the tall-to-short ratio from crossing two heterozygous tall plants, and to define dominant and recessive allele.
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   (i) Genotype: TT. Phenotype: tall. (ii) Cross: Tt × Tt → TT : Tt : tt = 1:2:1. Phenotype ratio: 3 tall : 1 short. (iii) Dominant allele: the allele that is expressed in the phenotype even when only one copy is present (heterozygous). Recessive allele: only expressed in the phenotype when two copies are present (homozygous recessive).
   Source: Department of Examinations, Sri Lanka — G.C.E. O/L Science 2022, Paper II, Question 8 · https://doenets.lk/pastpapers

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Where does DNA, Genes and Principles of Heredity fit in the syllabus?

Grade 11 · Term 3