1. (a) write down 2 distinguishing features between ATP and ADP.  1. (b) Is there any difference between cellular respiration and photosynthesis? Justify your answer in no more than 4 sentences.  1. (c) What makes aerobic respiration different from anaerobic respiration? Mention 2 such major distinguishing features. 
2. (a) Define chromosome and gene. [1+1] 2. (b) Show different allele combinations for Tall (T) character and mention their allele types.  2. (c) The following is the diagram of a pair of chromosomes. Identify a pair of alleles, a gene locus and three pairs of genes. 
3. (a) Write down the two important differences between the first phase of mitosis and the first phase of meiosis cell division.  3. (b) What makes HeLa cells different from any other cell types? What kind of cell division takes place in a HeLa cell line grown in a laboratory? [1+1] 3. (c) How many chromosomes are there in 4 duplicated chromosomes? 
4. (a) Write down two key features of DNA double helix.  4. (b) Explain why DNA replication is semi-conservative in nature (maximum 100 words).  4. (c) What would happen if a prokaryotic cell didn’t have the DNA polymerase enzyme? 
5. (a) What type of mutation occurred in the figure? Explain your reason within 100 words.  5. (b) Give a real life example of this type of mutation.  5. (c) Do you think any other type of DNA disorder can occur in the mentioned sequence due to the environmental causes? Why/Why not? Explain your reason within 100 words.