Question

(a) Name any two copper releasing intra-uterine devices. State two reasons that make them effective contraceptives.
(b) Name any two outbreeding devices that flowering plants have developed and explain how they help in encouraging cross-pollination.

Hint:

(a) Copper-releasing IUDs are highly effective as they not only prevent fertilization but also alter the uterine environment to reduce sperm mobility.
(b) Outbreeding devices like bright flowers and varying flowering times ensure cross-pollination, which increases genetic diversity in plants.

Answer 1

(a) Two copper-releasing intra-uterine devices (IUDs) are: 1. Copper-T 2. Multiload Cu375
Their contraceptive effectiveness stems from: 1. The release of copper ions, which establish a hostile uterine environment, inhibiting sperm from fertilizing the ovum. 2. Alterations to cervical mucus, increasing its viscosity and reducing sperm penetrability.
(b) Two outbreeding mechanisms in flowering plants that promote cross-pollination include: 1. Vividly colored blossoms: These attract pollinators such as bees, birds, and butterflies, facilitating pollen transfer between flowers. 2. Disparate flowering periods: Plants may exhibit varied flowering seasons to preclude self-pollination, thereby encouraging cross-pollination when different species or individuals bloom asynchronously.