Biology
The given figures A and B show …………… and …………… conditions which favour cross-pollination.
- Herkogamy and Heterostyly
- Heterostyly and Herkogamy
- Herkogamy and Homogamy
- Heterostyly and Homogamy
Answer
Herkogamy and Heterostyly
Reason — In herkogamy, a structural barrier or the relative position of anthers and stigma prevents self-pollination and promotes cross-pollination. In heterostyly, the style and stamens are of different lengths in different flowers, which promotes cross-pollination.
In homogamy, anthers and stigma mature at the same time. So, it favours self-pollination, not cross-pollination.
Related Questions
Wing and keel petals are found in the flowers of:
- Pea plants
- Vallisneria
- Maize plants
- Dahlia
Which of these does not belong to the embryo sac of a flower?
- Generative nucleus
- Antipodal cells
- Polar Nuclei
- Synergids
Look at the table given below and identify the kind of pollination that usually occurs in the flower mentioned.
Flower Kind of pollination Hibiscus P Hydrilla Q Wheat R - P — Entomophily, Q — Hydrophily, R — Anemophily
- P — Hydrophily, Q — Elephophily, R — Anemophily
- P — Ornithophily, Q — Anemophily, R — Elephophily
- P — Ornithophily, Q — Hydrophily, R — Entomophily
Given below is the internal structure of an ovule. Read the information below the diagram and fill in the blanks:
Ovule is located in the inner part of the ovary. It is destined to become the seed and the ovary to become the fruit. The number of ovules in the ovary vary from species to species. It can be one or more.
Each ovule has one or two protective coverings, the integuments. The integuments leave a small opening called the (a) …………… at one end. Enclosed by the integuments is the (b) ………………(a mass of food laden cells), and further inside it, is the embryo sac. Embryo sac contains one (c) …………… and two (d) …………… at one end. Three (e) …………… cells are found at the opposite end of embryo sac.