Why Sexual Reproduction? • Sexual reproduction in plants allows the offsprings to inherit beneficial qualities from both parents. • It helps to increase the genetic variation within the population and increases the chances of the species’ survival.
About the Flower… • The flower is the reproductive organ of a plant. • Flowers may occur individually or in clusters called influorescences. • A complete flower consists of the pedicel, receptacle, sepals, petals, stamens and carpels. • Some flowers may lack one or more parts and are known as incomplete flowers.
Parts of a Flower blog.lib.umn.edu
Pollination • Self-pollination: pollen transferred within same flower OR from one flower to another on the same plant • Cross-pollination: pollen transferred from one flower to another on different plants of the same species
Self-pollination • bisexual flowers with anthers and stigmas maturing at the same time. • stigma is situated below the anthers. • in some plants, the flowers do not bloom open. Hence the flower can only self-fertilise.
Question • What are the advantages and disadvantages of self-pollination?
Cross-pollination • plants bear either male flowers or female flowers. • anthers and stigmas mature at different times. • anthers and stigmas may be position away from one another.
Question • What are the advantages and disadvantages of cross-pollination?
After successful fertilisation • the ovule develops into the seed • the ovary develops into the fruit
Dispersion • After the fruit and seeds are formed, they have to be dispersed in order for the species to conquered new territories. • The fruit and the seeds have to be adapted for their specific mode of dispersal.
Useful Links • http://www.bcb.uwc.ac.za/ecotree/flowers/flowerparts.htm • http://www.buzzaboutbees.net/pollination-of-flowers.html • http://www.youtube.com/watch?v=ge3EM8AERV0