AP BIOLOGY

Detailed explanation-1: -Megasporangium is equivalent to the ovule which is present inside the ovary that is connected to the cushion which is referred to as the placenta. It consists of a single embryo sac that is formed from a megaspore employing reduction division.

Detailed explanation-2: -Each ovule contains an egg. 1 Pollen grains land on the stigma and begin to grow pollen tubes. Sperm cells within the pollen grain move down the pollen tube and into an ovule. Fertilization occurs as one of the sperm cells fuses with the egg inside the ovule.

Detailed explanation-3: -OVULE AND SEED DEVELOPMENT. After pollination, the megasporocyte develops within the megasporangium of the ovule (Figures 5.10A, 5.11A). The megasporocyte is a single cell that undergoes meiosis, producing a tetrad of four haploid megaspores (megasporogenesis).

Detailed explanation-4: -Megasporangium in Angiosperms Megasporangium or the ovule contains megaspores. Megaspores further divide to give rise to the megagametophyte. After this division, remnants are the only things left, and they form the whole of the nucellus. Hence, Nucellus is the megasporangium in an Angiosperm ovule.