Question

Annie was conducting research on the number of fruits produced by watermelon under different conditions. She grew 25 watermelon plants each in both glass house A and B. She introduced pollinators in glass house A only.

1. What difference will she observe in the number of fruits produced in the two glass houses? Explain with reason.
2. List 3 changes that will occur in a flower once it gets fertilized.

Answer 1

1. Watermelon has unisexual flowers; the male and female flowers are separate. The presence of pollinators will facilitate cross pollination between the flowers, increasing the chance of fertilisation and the number of fruits being produced. Without pollinators the probability of pollen falling on the stigma reduces in a unisexual flower, especially if they are far apart; thus, the number of fruits produced will be less.
2. The three changes observed are:
   1. An ovule develops a tough coat and becomes a seed.
   2. The ovary grows and ripens to form fruit.
   3. Petals, sepals, stamen, style and stigma may shrivel and fall off.