In a plant species, the allele for purple flowers (P) is dominant over the allele for white flowers (p), and the allele for tall plants (T) is dominant over the allele for short plants (t). A plant that is heterozygous for both traits (PpTt) is crossed with a plant that has white flowers and is short (pptt).

 a) What are the genotypes of the parent plants? (2 marks) 

 b) What are the possible gametes produced by the heterozygous plant? (4 marks) 

 c) Use a Punnett square to determine the genotypic and phenotypic ratios of the offspring. (9 marks)

2. (15 marks)** **Gene Expression and Regulation:

 Explain the process of transcription and translation in eukaryotic cells. Include in your answer the roles of mRNA, tRNA, and rRNA. Discuss how gene expression can be regulated at the transcriptional and post-transcriptional levels.

3. (20 marks) Genetic Diseases:

 Discuss the genetic basis of sickle cell anemia and Huntington's disease. Compare and contrast the inheritance patterns, molecular mechanisms, and the impact of these diseases on affected individuals. Include a discussion on how genetic testing and counseling can assist families with a history of these conditions.