Mention any three contrivances in flowers which favour cross-pollination.

Explanation

**Step-by-Step Solution:**

1. **Understanding Cross-Pollination**: Cross-pollination is the transfer of pollen from the anther of one flower to the stigma of another flower, which promotes genetic diversity in plants. Certain adaptations in flowers facilitate this process.

2. **Contrivance 1: Dicogamy**:
- Dicogamy is a phenomenon where the maturation of the male and female reproductive parts occurs at different times.
- There are two types of dicogamy:
- **Protandry**: In protandry, the anthers (male part) mature before the carpels (female part). This ensures that pollen is released before the stigma is ready to receive it, promoting cross-pollination.
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