In tobacco plant, the male gametes have twenty four chromosomes. What is the number of chromosomes in the female gamete? What is the number of chromosomes in the zygote?

Would a Planaria cut vertically into two halves regenerate into two individuals? Complete Figure ‘D’ and ‘E’ by indicating the regenerated regions.

From the internet, gather information about the chromosome numbers of five animals and five plants. Correlate the number with the size of organism and answer the following questions.

(a) Do larger organisms have more number of chromosomes/cells?

(b) Can organism with fewer chromosomes reproduce more easily than organisms with more number of chromosomes?

(c) More the of chromosomes/cells greater is the DNA content. Justify.

Why cannot fertilisation take place in flowers if pollination does not occur?

Is the chromosome number of zygote, embryonal cells and adult of a particular organism always constant? How is the constancy maintained in these three stages?