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chromosomes. This creates variation among individuals, which is important for the survival of a species. Variation helps some individuals adapt better to changing environments and over time, this process contributes to evolution. For example, some people can tolerate low oxygen levels at high altitudes, or digest milk in their adulthood. 11.2.2 Sexual reproduction in flowering plants Flowering plants, also called angiosperms, are the most diverse group of plants on the Earth. Flowers serve as reproductive organs in angiosperms, however, non-flowering plants like pines also reproduce sexually. You will study them in the next chapter. Look at the herbs, shrubs and trees in your surroundings. Their leaves perform photosynthesis, their roots absorb water and nutrients from the soil, and their stems provide strength to the plant, these are some of the functions of a plant. Flowers also enhance the aesthetics of the plants as they are coloured and/or fragrant. How are these features of flowers useful for reproduction? Explore flowers and their buds on some plants. Record your observations in your notebook. Do you observe thin, flat, green covering, Anther and coloured projections present in both? Stamen Stigma In flower buds, the coloured projections are Filament often covered by a green covering. In the bud Style stage, green covering around all the parts is the outermost whorl of the flower. This Petal Pistilstructure is called a sepal. Do you think that Sepal sepals protect flowers in the bud stage, along with other parts of the flower when it blooms? Ovary The coloured projections of flowers are called petals (Fig. 11.10). Do all flowers have these Fig. 11.10: Longitudinal section of a flower showing its different parts twoparts?Whataretheotherpartsofaflower? Activity 11.5: Let us explore 1. Collect different types of flowers from your surroundings. 2. Carefully observe each part of the flowers you have collected, starting from the outer whorl to the inner one. 3. Record the presence of various floral parts in the different flowers that you collected in Table 11.1. Table 11.1: Observation table to study the parts of a flower Presence of floral parts in different Guess the S. No. Flower parts flowers Other function of feature(s) flower part A B C D 1. Sepal Yes 2. Petal Yes 3. Stamen No 4. Pistil Yes 214 Exploration|Grade 9