SEMESTER 3 Practical Science 1 Experiment 7 Topic: Investigating the structure of flowers, Angiospermatophyta. Purpose: A: To investigate the morphology of the flame of the forest (Delonix regia) flower and its relation to its function. Theory:
Flowers vary greatly in structure. The fundamental similarities among flowers of different kinds of plants are, however, greater than their differences, since all flowers have the same basic structural plan. Each individual flower is borne at the tip of a speciali speciali zed stalk known as a pedicel. The floral organs borne by the pedicel are usually grouped in four concentric whorls. Sepals make up the outermost whorl of floral organs. Sepals surround and protect the other parts of the developing flower. Petals make up the next whorl. Most animalpollinated flowers have bright petals to attract the pollinators. The two innermost whorls contain the reproductive structures. The male reproductive organs are the stamens. Stamens have two parts: a pollen sac ( anther ) on the end of a stalk (filament). (filament). An anther contains mirosporangia, mirosporangia , which produce microsporesthat microspores that mature into pollen into pollen grains. grains . The innermost whorl contains the female reproductive structures, which are called carpels. One or more carpels fused together make up the structure called a pistil . The pistil is comprised of a swollen base called the ovary containing the ovules (eggs), the stalk-like style rising from the ovary, and the hairy hairy or sticky pollen pollen trapping tip of the style known as the stigma. stigma. Flowers containing all four whorls are known as complete or perfect or perfect flowers. flowers. Any flowers lacking one or more of the four whorls are termed incomplete flowers. Some types lack sepals or in the case of the tulips and lilies, the sepals are brightly colored and identical to the petals. Others may lack petals and possibly sepals as well. Members of the grass family all form incomplete flowers lacking both petals and stamens. Grass flowers are so small and so drab due to lack of petals that most people aren¶t aware they even exist. Or people don¶t recognize them as flowers because they confuse flower and petal as being synonymous when they in fact are not. Some flowers lack one set of sexual organs. Plants whose flowers have only male stamens but no female pistils are said to be incomplete staminate flowers. Those with pistils but lacking stamens are said to be incomplete pistilate flowers.
From the human perspective, the flower may well be the second most important plant structure on the planet (Leaves are undoubtedly the most important). Flowers produce the seeds that allow all the plant species we depend upon for our food, materials, medicine, and general comfort of life to continue to exist. Radially symmetrical flowers are called actinomorphic and bilaterially symmetrical flowers called zygomorphic flowers. Floral diagram provides a plan of the flower as viewed from above. It looks like diagrammatic cross-section. If a bract, a leaf-like structure immediately beneath the flower, is present it should be facing you, the flower stalk should be furthest away and the main stem of the plant should be at the top of the flower. You will probably cut a cross -section of the ovary so that we can show the position of the ovules in the diagram. If the petals, sepals, or stamens are joined, link them with simple brackets. If the stamens arise from the petals, link them with radial lines.
Apparatus and Material: 1.
2. 3. 4. 5. 6.
Flame of the forest flower Orchid flower Knife Hand lens Tiles Ruler
Procedures:
The flower was cut into two equal halves using a knife. A large labelled drawing of the dissected flowers was make as well as the floral diagram. The scale of drawing is stated. Scale:
B: To investigate the morphology of the orchid flower and its relation to its function.
Apparatus and Material: 1.
2. 3. 4. 5.
Orchid flower ( Dendrobium) Knife Hand lens Tiles Ruler
Procedure:
The flower is cut into two equal halves using a knife. A large labelled drawing of the dissected flower is make as well as the floral diagram of the flower. The le of the drawing is stated
Discussion
A flower is basically made up of four concentric rings of structures. There is an outer ring of modified leaves called sepals. These provide protection to the flower before it opens and are usually green. This outer ring is known as the calyx. Inside the sepals is another ring of modified leaves called petals which are often brightly coloured. This layer is known as the corolla. Within the corolla are one or more stamens conta ining pollen, which are the male reproductive structures. In the very centre of the flower are the female reproductive organs.The female parts of a flower consist of an ovary, which contains one or more ovules, a style and the stigma. The ovary is at the b ase of the flower. From the ovary, extends a tubular structure called the style and on the top of the style is a surface receptive to pollen called the stigma.The stigma can take many different forms, most of them designed to help trap pollen. There are ma ny variations on this basic structural theme. The male parts of a flower consist of one or more stamens. Each stamen is made up of paired anthers (sacs containing pollen) on a filament or stalk.The anthers are the orange/yellow structures often seen in the centre of a flower. Pollen from the anthers of one flower is transferred to the stigma of another usually either by wind, or by animals, especially insects. Flowers do not always have the two outer layers of calyx and corolla. These two layers are most noticeable in plants which are pollinated by insects. The corolla or petals are often brightly coloured with markings attractive to insects. The flowers may also be scented. For instance, Honeysuckle has showy, attractive flowers which attract insects by day. However, in the dark, their colourful show is not much use, and their heady scent then helps to attract night -flying moths. In insect-pollinated plants, there are also usually nectarines which secrete sugary nectar, located within the flower. These provide an incentive to insects to visit the flowers. In the search for nectar, the insects will often get pollen grains caught on their bodies. This may then brush off onto the stigma of the next flower visited and in this way the flowers are pollinated. Many flowers have evolved very specific associations with a particular insect species or group of species. In these cases flower structure may be very specialized (e.g. orchids). Foxgloves (Digitalis purpurea) and Primroses (Primula vulgaris) show a range of adaptations to insect pollination. Wind pollination is also common in flowering plants. In this case, because there is no necessity to attract insects, the calyx and corolla of the flowers may be absent.
Flame of the forest
In this flower we had discovered that this flower is a type of. For the structure for this flower is can be divided into many characteristic. The peduncle for this flower stalk is green in colour. The receptacle part of flower is to stalk bearing the floral organs, at base of flower and the colour of receptacle is green in colour. Sepal is leaf-like structures at flower base and the function of sepal to flower is to protect young flower bud. Flame of the forest has five sepals and the colour is red at the top and green in colour at the bottom of sepals. Petal of flame of the forest is located in and above the sepals, often large and colourful red in colour, sometimes scented, sometimes producing nectar. Often serve to attract pollinators to the plant and Flame of the forest has five petals. The texture of this flower is soft and the thickness of this plant also thin. These flower parts are arranged spirally or in whorls around the receptacle. Dicotyledonous flowers usually have four whorls, whereas monocotyledonous flowers typically have three whorls. The third whorl, the endroecium,consist o f stamens which are the male reproductive organs of the flower. Each stamen is made up of anther and filament. This flower of Flame of the Forest has 10 stamens. The anther is brown in colour that contains pollen sacs which produce pollen. The filaments of this Flame of the Forest have red in colour that contains vascular tissue which carries food and water to the anther. The gynaecium or pistil is the whorl at the centre of the flower, and it is made up of one carpels in this flower Flame of the Forest. Carpels have three main parts. First is a swollen base, the ovary which contains one ovule. These parts develop into seed after fertilisation. Seconds, a sticky or feathery tip called the stigma for easy adherence of pollen grains. Thirds is a stalk called the style which holds the stigma in a suitable position to receive pollen. If the ovary is inserted above the other whorls on the receptacle, it is called a superior ovary and if the position of the ovary o the receptacle is below the ot her whorls, it is called an inferior ovary. From the observation during experiment I had seen the position of the ovary for this Flame of the Forest and the position of the ovary is inserted above the other whorls on the receptacle and for sure it is superior ovary. Flower may be actinomorphic or regular, that is, the floral parts are arranged in radial symmetry on the receptacle, or they may be zygomorphic or irregular, that is, the floral parts show bilateral symmetry only. From this experiment this flower of Flame of the Forest has actinomorphic or regular this is because we can cut the flower in many part or line to get radial symmetry.
Orchid
In this flower we had discovered that this flower is a type of Dendrobium flower. For the structure for this flower is can be divided into many characteristic. The peduncle for this flower stalk is yellow in colour. The receptacle part of flower is to stalk bearing the floral organs, at base of flower and the colour of receptac le is yellow in colour. Sepal is leaf -like structures at flower base and the function of sepal to flower is to protect young flower bud. Orchid flower has one dorsal sepals and two lateral sepals that yellow with purple dot colour. Petal of orchid flower is located between the sepals, often same colour with sepals in colour . Often serve to attract pollinators to the plant and orchid has two petals. The texture of this flower is soft, rough and the thickness of this plant also quite thick than flame of the forest.. Dicotyledonous flowers usually have four whorls, whereas monocotyledonous flowers typically have three whorls. The third whorl, the endroecium,consist of stamens which are the male reproductive organs of the flower. Each stamen is made up of anther and filament. This flower of orchid has anther cap and stigma in same position or we can say in same column foot. The anther cap is purple in colour that contains pollen sacs which produce pollen. The filam ents of this orchid have red in colour that contains vascular tissue which carries food and water to the anther. The gynaecium or pistil is the whorl at the centre of the flower, and it is made up of one carpels in this orchid. As you know this orchid anther share same column foot with carpel. To simple the discussion we say that the orchid column . Orchid column have four stage of structure. First is a anther cap, second is the stigma, third is column foot and lastly the ovary which contains one ovule. These parts develop into seed after fertilisation. Seconds, a sticky or feathery tip called the stigma for easy adherence of pollen grains. If the ovary is inserted above the other whorls on the receptacle, it is called a superior ovary and if the position of the ovary o the receptacle is below the other whorls, it is called an inferior ovary. From the observation during experiment I had seen the position of the ovary for this orchid and the position of the ovary is inserted above the other whorls on the receptacle and for sure it is superior ovary. Flower may be actinomorphic or regular, that is, the floral parts are arranged in radial symmetry on the receptacle, or they may be zygomorphic or irregular, that is, the floral parts show bilateral symmetry only. From this experiment th is flower of orchid has zygomorphic or irregular this is because we can¶t cut the flower in many part or line to get radial symmetry. Hence to get the symmetry line only one line that can be cut.
Precaution: 1.
Use the sharp knife to cut the flower without imperfectly separates the flowers parts. 2. Handle the knife with carefully without being injured. 3. Cut the flower with arranged in radial symmetry on the receptacle whether the flower is actinomorphic or zygomorphic.
Conclusion
The phylum Angiospermophyta comprises flowering plants which produce seed protected by an ovary wall. The whole structure is called a fruit. The flower is an organ of asexual reproduction ( produce spore) and sexual reproduction ( produce gametes ). All flowers have the same basic structure like they have petal, sepal and many more but the total of part of flower and floral part be might different. The different of flower we can see from the structure, type of symmetry, and pollination structure this is because flower need to be comfortable their structure to make all the process become success.
Question: 1.
State the family, type of ovary and the symmetry of both flowers that are being investigated.
Name of Flower Family T ype
of ovary
Symmetry of flower
Flame of the Forest F abaceae
/ (Bean family)
Leguminosae
Orchid Orchidaceae
Superior ovary
Inferior ovary
Actinomorphic (Radially symmetrical)
Zygomorphic flower flower (Bilaterally symmetrical)
2. What are the special features, which both flower has to ensure the success of their fertilization process?
i.
Flame of the Forest
The flowers have attractive colour and contain much nectar is evidenced by the frequent visits of many species of birds; sunbirds, mynahs and babblers are usually to be seen, hurrying from flower to flower. ii.
Orchid
Pollinators are often visually attracted by the shape and colours of the labellum. The flowers may produce attractive odours. When the pollinator enters into the flower, it touches a viscidium, which promptly sticks to its body. While leaving the flower, it pulls the pollinium out of the anther, as it is connected to the viscidium by the caudicle or stipe. The caudicle then bends and the pollinium is moved forwards and downwards. When the pollinator enters another flower of the same species, the pollinium has taken such position that it will stick to the stigma of the second flower, just below the rostellum, pollinating it.
Reflection
Firstly thanks to God that still makes me breathing in this world with peacefully. I would like to thanks to Pn. Siti Rogayah Binti Abdullah that always help me and my friends to solve this experiment more professional and thanks to him again be cause of his spirit to teach we her good personality. Then, thanks also to my all friend that always help me to done this report. Before we carried out this experiment, we had been informing what to do in this experiment with clearly. We had been explained by our lecturer about how to dissect this flower with carefully without any mistake. Through this experiment I feel more excited because to do the experiment of dissection of the flower need patient and knowledge because it is hard to see t he inner part of flower like an ovule . This experiment teaches us to think critically that develop our minds to set in critical thinking skill to handle any situation in experiment time. Other that, through this experiment I had get many thing about dissection of the Angiospermatophyta flower because through this experiment we can know more deeply about how the flower carry on the pollination that is involving many part of flower and other creatures. Lastly I hope another biology experime nt will come soon because I¶m excited to do the biology experiment and report. Apologize to all if my report has any problems or error and I promise to do more carefully for the next experiment.
Reference 1.
Pre-u Text STPM Biology Volume 2, Lee Ching, J. Arunasalam, PEARSON MALAYSIA SDN. BHD. 2. Hassan Abdullah (2009). Biology for Matriculation Semester I. Shah Alam: SAP Publications. Foo Yuen Kooi (2 003). STPM Biology Volume I. Bangi: Penerbitan Pelangi. 3. Web Page=Johnson R.S (2008). This is the title of a Web Page. http://botanydeItaly.net. Accessed on 20 July 2010. K.V. Fernandez (2006). This is the title of a Web Page. http://www.lovingflower.com . Accessed on 20 July 2010.
Result & Observation:
Result & Observation:
