Question

Plant Lab Select 3 differently shaped flowers from a florist or grocery store – (Walmart even has a decent selection – a lily, a carnation, and a snapdragon are all nice and very different from one another). • Find out what kind of flowers you have and find an image of each on the internet – It would be best if you can find one that talks about flower parts • For each flower, note whether there are sepals, petals, stamens, and carpels and record the information about them below as best you can. • Most of the flowers you select have been genetically or otherwise modified. Do you see the presence of any “extra or missing” structures – for example, natural flowers only have 3-5 petals. o Note any modifications that you observe. Flower #1 • Name: • Sepals (present or absent, #, color): • Petals (present or absent, #, color, symmetrical-radial/lateral) • Stamens (separate or attached to other structures, long or short filaments, is pollen present?) • Carpel (what shape is the stigma, is the style long/short, how many ovules can you see (if you take a knife and cut the ovule open transversely (on the short axis) this may be easier to see) Flower #2 • Name: • Sepals (present or absent, #, color): • Petals (present or absent, #, color, symmetrical-radial/lateral) • Stamens (separate or attached to other structures, long or short filaments, is pollen present?) • Carpel (what shape is the stigma, is the style long/short, how many ovules can you see (if you take a knife and cut the ovule open transversely (on the short axis) this may be easier to see) Flower #3 • Name: • Sepals (present or absent, #, color): • Petals (present or absent, #, color, symmetrical-radial/lateral) • Stamens (separate or attached to other structures, long or short filaments, is pollen present?) • Carpel (what shape is the stigma, is the style long/short, how many ovules can you see (if you take a knife and cut the ovule open transversely (on the short axis) this may be easier to see) Answer the following questions: 1. What is the function of sepals? 2. Why do we create modified flowers to sell to consumers? Would these modifications be an advantage or disadvantage in the wild (justify your answer)? 3. Many flowers have developed mechanisms to prevent self-pollination. Based on your observation of the position of male/female structures, why is the necessary? Use the text or internet to find 2 examples of ways plants prevent self-pollination. Select 3 fruits/veggies from the store – get 2 of each (not root veggies like potatoes or carrots or celery) • Observe the outside of the fruit and note any remaining flower parts. • Cut one fruit horizontally and one longitudinally. • Observe the layers of the fruit and the position of seeds. • Use the following information to classify your fruits – if it is a berry make sure you decide if it is “just a berry” or if it is a hesperidium or pepo. I. Simple Fruits - Fruits formed from 1 pistil. They may be either true or accessory fruits. B. Fleshy Fruits - A fruit in which the wall becomes soft and fleshy as it matures. 1. Drupe - A one-seeded simple fruit developed from a superior ovary in which the innermost portion of the wall (endocarp) becomes hard and stony, the outermost part (exocarp) becomes a relatively thin skin, and the middle portion between the skin and the stone (mesocarp) becomes either fleshy or fibrous. (cherry, coconut) 2. Berry - A simple fruit in which the ovary wall or at least its inner portions become enlarged and usually juicy. (grape, gooseberry). Two special types of berry-like fruits may be singled out for special consideration. (a) Hesperidium - This is a special type of berry in which a leathery rind forms; the interior of the fruit divided by septa, indicating the number of carpels. (b) Pepo - This is a special type of berry in which a relatively hard rind is formed; the interior of fruit not divided by septa. (squash) 3. Pome - An accessory fleshy fruit formed by a group of carpels more or less firmly united with each other and surrounded by and united to the floral tube or receptacle. (pear) II. Aggregate Fruit - A fruit formed by the development of a number of pistils from the same flower. The individual units may be berries or other specific types. (raspberry) III. Multiple Fruit - A fruit formed by the development of a number of pistils often with accessory parts, the pistils being from a number of flowers. (mulberry) Fruit #1 • Name: • Remaining flower parts: • Type of fruit • Distinguishing characteristics that you based your type on Fruit #2 • Name: • Remaining flower parts: • Type of fruit • Distinguishing characteristics that you based your type on Fruit #3 • Name: • Remaining flower parts: • Type of fruit • Distinguishing characteristics that you based your type on Answer the following questions: 1. Why are these fruits “fleshy” – what is the purpose of the flesh? 2. What advantages do you see in each of the fruits you observed in terms of protecting and distributing their seeds.

Answer 1

1) The fleshy fruits contain nutrients required for the germination of seeds. It also acts as a protective cover for seeds and help in seed dispersion.

2) The outer pericarp gives protection to seeds. It also attracts animals that consume them thereby helping in dispersal if seeds.