Pollen grain marks the begining of male gametophyte. First Mitotic Division During the initial mitotic division, it generates a larger, naked vegetative cell and a smaller, thinly-walled generative cell. The vegetative cell is rich in food and having irregular shaped nucleus. The generative cell floats in the cytoplasm of vegetative cell. Second Mitotic Division In … Read more
Double fertilization is a unique and crucial process in flowering plants, involving two sperm cells and two female gametes, ultimately leading to both embryo and food source development. It was discovered by Nawaschin in the liliaceous plants like Lilium and Fritillaria. Pollen grains, carrying two male gametes, which lands on the stigma, the sticky landing … Read more
Three Devices Encouraging Cross-pollination in Angiosperms: 1. Dioecy: Separate male and female flowers on different plants, preventing self-pollination. Examples: Willow, spinach, hemp. 2. Dichogamy: Timing mismatch between pollen release and stigma receptivity. 3. Hermaphroditism with Structural Barriers: Physical separation of male and female parts within the same flower. Examples: Hibiscus, iris, snapdragon. Bonus: Self-incompatibility: Genetic … Read more
Incompatibility refers to a suite of pre-zygotic barriers in plants that prevent fertilization between genetically incompatible individuals. This mechanism essentially serves as a natural “bouncer” system, promoting outbreeding and enhancing offspring fitness.
The statement that pollination and seed formation are crucial for fruit formation is absolutely correct. Here’s why: Pollination: Triggers fruit development: Pollination acts as the initial signal for the ovary of the flower to start developing into a fruit. Provides genetic diversity: Pollen grains typically carry male genetic material from another plant, which, upon fertilization, leads to the … Read more
Polyembryony’s commercial potential lies in its ability to produce multiple identical plantlets from a single seed. Here’s how it’s exploited: Reduced seed cost Clones of desirable plants Rootstocks for grafting Disease-free plantlets Faster breeding programs
The primary function of the filiform apparatus is to guide the pollen tube into the embryo sac, specifically towards the egg cell for fertilization.
The two key parts of the pistil that develop into fruits and seeds are: Ovary: This swollen base of the pistil contains ovules, the precursors to seeds. After fertilization, the ovary wall thickens and ripens to become the fruit. Ovules: These are tiny structures within the ovary that contain egg cells. Once fertilized, ovules develop … Read more
Pollination and fertilisation is not required in apomixis as there is no involvement of male gametes in this process.
Parthenocarpy is the natural or artificially induced development of seedless fruits without fertilization.