Plant Biology - Biology and Society - Lecture Notes, Study notes of Biology

Download Plant Biology - Biology and Society - Lecture Notes and more Study notes Biology in PDF only on Docsity! 1 Plant Lab Materials for lab Bring a digital camera if you have one available Teaching Objectives Plant diversity: Applications and importance Plant form and function: Plant survival and human use Local and global examples of terrestrial plant types Student Learning Objectives (1) View the plant diversity on campus (2) Know how to access information regarding plant identification (3) Be aware of differences between mosses, ferns, and flowering plants Plant Biology Docsity.com 2 INTRODUCTION Plants are the producers in a food web. Solar energy is stored in the chemical bonds of the sugars produced by plant photosynthesis, the biochemical process by which plants utilize light energy from the sun to produce sugar from carbon dioxide and water. Consumers in a food web derive their energy by breaking down these bonds during respiration, which releases the stored energy. Energy flowing within the food web therefore enters it by way of plant photosynthesis. The importance of plants to the survival of humans and other animals cannot be over-emphasized. Our basic needs of oxygen, food, shelter, and clothing are provided, directly or indirectly, by plants. Because plants absorb carbon dioxide and release oxygen in photosynthesis, they may be a significant factor in reducing the "greenhouse effect", which is caused by human activities that increase the carbon dioxide in the atmosphere. Deforestation and the burning of fossil fuels (oil, coal, and gas) are two examples of such activities. There are about 235,000 species of flowering plants in existence today. Approximately a third of these are native to temperate regions, and the remainder are found in the tropics. A vast number of tropical plants are in danger of extinction in the wild within the next hundred years because the human populations of most tropical countries continue to double every 20 to 25 years, and because the forests are rapidly being cleared for wood and cultivation. More than half of the world's tropical forests have already been cleared, and experts predict that most of what is left will be gone in less than 50 years. With them will vanish a quarter of all life-forms including, perhaps, a plant that could provide a cure for cancer or help end world hunger. So little is known of the plants of the tropics that many have not even been given scientific names. Preserved samples of these plants may well be all that are passed on to our descendants in the 21St century and beyond. The useful properties these plants possess can certainly be determined better today, when species are still in existence, than at any point in the future. This week's lab is designed to introduce you to the incredible diversity within the plant kingdom, to note some of the purposes for which plants have been utilized by humans, and to help you appreciate the forms into which they have been modified and shaped by evolution. Docsity.com 5 Basic leaf shapes Sword-shaped (ensiformis) Long, thin, pointed Lance-shaped (lanceolata) Long, wider in the middle Ovate (ovata) Oval, with a tapering point Elliptic (elliptica) Oval, with a short point Round (rotundifolia) Circular Cordate (cordata) Heart-shaped Oblanceolate (oblanceolata) Top wider than bottom Spathulate (spathulata) Spoon- shaped Rhomboid (rhomboidalis) Diamond- shaped Lobed (lobata) With several points Spear-shaped (hastata) Pointed, with barbs Pinnatisect (pinnatifida) Cut, but not to the midrib Pinnate (pinnata) 2 rows of leaflets Bipinnate (bipinnata) Each leaflet also pinnate Tripinnate (tripinnata) Each leaflet divided into 3 Trifoliate (trifoliata) Divided into 3 leaflets Palmate (palmata) Divided into many lobes Digitate (digitata) Divided into 5 lobes Opposite (oppositifolia) Leaves opposite one another Alternate (alternifolia) Arranged alternately Perfoliate (perfoliata) Stem through the leaves Peltate (peltata) Rounded, stem underneath Whorled In circles round the stem Rosette Leaves in close rings Docsity.com 6 FLESHY FRUITS formed from a single flower Berry A Berry is a single fleshy fruit without a stone, usually containing a number of seeds. This is a Kiwi Fruit (Actinidia chinensis). Other fruits of this type are: Banana (Musa), Coffee (Coffea arabica), Currant (Ribes), Pasionfruit (Passiflora), Pepper (Capsicum), Tomato (Lycopersicon esculentus). Drupe A Drupe is a single fleshy fruit with a hard stone which contains the single seed. This is a Cherry (Prunus avium). Other fruits of this type are: Apricot (Prunus armeniaca), Plum (Prunus x domestica), Coconut (Cocos nucifera), Olive (Olea europaea), Peach (Prunus persica), Sloe (Prunus spinosa). Aggregation of Drupes An Aggregation of Drupes is a fleshy fruit, made up of many drupes but formed from a single flower, each drupe containing one seed. This is a Raspberry (Rubus idaeus). Other fruits of this type are: Loganberry (Rubus), Blackberry (Rubus fruticosus). Pome A Pome is a fleshy fruit with a thin skin, not formed from the ovary but from another part of the plant. These are sometimes called Accessory Fruits. The seeds are contained in chambers in the centre of the fruit. This is an Apple (Malus domestica). Other fruits of this type are: Firethorn (Pyracantha), Hawthorn (Crataegus), Medlar (Mespilus germanica), Pear (Pyrus communis), Quince (Cydonia oblonga). Hesperidium A Hesperidium is a berry with a tough, aromatic rind. This is an Orange (Citrus sinensis). Other fruits of this type are all Citrus fruits: Citron (Citrus medica), Grapefruit (Citrus x paradisi), Kumquat (Fortunella), Lemon (Citrus limon), Lime (Citrus aurantifolia). There are other types of fleshy fruit which some people classify separately. A Hep or Hip is a fleshy fruit containing achenes, as in the Rose (Rosa); a Pepo is a fleshy fruit with a leathery skin, formed from an inferior ovary. This type of fruit is found only in members of the Gourd Family (Cucurbitaceae) - Cucumbers (Cucumis melo), Water Melon (Citrullus lanatus), Pumpkin (Cucurbita maxima), and Pseudocarp. Docsity.com 7 Pseudocarp A Pseudocarp is a false fruit, because it does not contain the seeds. The seeds are achenes, on the outside of a fleshy fruit. This is a Strawberry (Fragaria x ananassa). FLESHY FRUITS formed from a group of flowers There are a few fruits formed from a group of flowers (inflorescence) rather than just one, but which form only one fruit. These are Sorosis, as in the Mulberry (Morus), Syngonium, as in the Fig (Ficus), and Coenocarpium, as in the Pineapple (Ananas). DRY DEHISCENT FRUITS Follicle A Follicle is a dry dehiscent fruit which splits on one side only. It may contain one or many seeds. This is the fruit of a Columbine (Aquilegia). Other fruits of this type are: Delphinium (Delphinium), Larkspur (Consolida), Love in a Mist (Nigella damascena), Milkweed (Asclepias), Peony (Paeonia). Legume A Legume is a dry dehiscent pod that splits on two sides. This is the fruit of a Sweet Pea (Lathyrus odoratus). Other fruits of this type are all in members of the Pea Family (Leguminosae/Fabaceae): Acacia (Acacia), Alfalfa (Medicago sativa), Liquorice (Glycyrrhiza glabra), Flamboyant (Delonix regia), Pea (Pisum sativa), Peanut (Arachis hypogaea), Redbud (Cercis occidentalis), Runner Bean (Phaseolus coccineus), Wisteria (Wisteria). Lomentum A Lomentum is a dry dehiscent fruit, a legume constricted between the seeds. This is the fruit of a Golden Chain Tree (Laburnum anagyroides). Other fruits of this type are: Sophora (Sophora), Tick Trefoil (Desmodium). Silique A Silique is a dry dehiscent fruit. It is long and thin, splits down the two long sides, and has a papery membrane (the septum) between the two halves. This is the fruit of a Wallflower (Erysimum cheiri). Other fruits of this type are all in members of the Cabbage Family (Brassicaceae): Aubrieta (Aubrieta x cultorum), Cabbage (Brassica olearacea), Honesty (Lunaria annua), Radish (Raphanus sativus). A silique which is less than twice as long as broad is called a Silicula. Docsity.com 10 Flower Parts Docsity.com 11 Flower Parts Terms Flower part Part function Petal Petals are used to attract insects into the flower, they may have guidelines on them and be scented. Stigma Is covered in a sticky substance that the pollen grains will adhere to. Style The style raises the stigma away from the Ovary to decrease the likelihood of pollen contamination. It varies in length. Ovary This protects the ovule and once fertilization has taken place it will become the fruit. Ovule The Ovule is like the egg in animals and once fertilization has taken place will become the seed. Receptacle This is the flower's attachment to the stalk and in some cases becomes part of the fruit after fertilization e.g. strawberry. Flower stalk Gives support to the flower and elevates the flower for the insects. Nectary This is where a sugary solution called nectar is held to attract insects. Sepal Sepals protect the flower whilst the flower is developing from a bud. Filament This is the stalk of the Anther. Anther The Anthers contain pollen sacs. The sacs release pollen on to the outside of the anthers that brush against insects on entering the flowers. The pollen once deposited on the insect is transferred to the stigma of another flower or the same flower. The ovule is then able to be fertilized. Please note: The stigma, style, ovary, and ovule are often known collectively as the carpel or female parts of the flower. The filament and the Anthers are collectively known as the Stamen or the male parts of the plant. Docsity.com 12 Flower Types • Imperfect Flower A flower that has either all male parts or all female parts, but not both in the same flower. Examples: cucumbers, pumpkin, and melons. • Perfect Flower A flower that has both the male parts and female parts in the same flower. Examples: roses, lilies, and dandelion. Docsity.com 15 Assignment 1 • Identify 20 leaf shapes (Table 1). • Draw an outline and vein patterns in your field book • Bring a small sample back for identifying plant parts (don’t take from the Hawaiian garden) • Bring a flower back for identifying flower parts (don’t take from the Hawaiian garden and one per group). Draw in field book. • Is it perfect or imperfect? • Go to the grocery store or China Town and identify 20 types of fruits or seeds (Table 2). Take a picture of you at the grocery store. You can show me it on your cell phone next week. • Due next week Compare Ferns, Gymnosperms & Angiosperms FERNS Ferns do not form flowers or seeds; instead they produce reproductive bodies called spores. When the spores are mature they are released and are spread by the wind. The spores germinate when they land on sufficiently moist soil. Laua'e Fern or Maile-Scented Fern (Phymatosorus grossus) Fern leaves are called fronds. Turn a frond over carefully and observe the underside. Notice the patches of dots. These are the reproductive structures of a fern; they are called sporangia. Spores are produced in the sporangia by a process called meiosis. During meiosis, the number of chromosomes (the nuclear structures containing DNA) in a dividing cell is reduced by half. These spores then germinate to produce a tiny, heart-shaped plant that lays close to the moist ground. Following fertilization within this tiny plant, the embryo has the potential to grow into a new fern plant. The maile-scented fern is native to the Hawaiian Islands and to many other islands in the Pacific Ocean. Squash a little bit of the frond and smell it; it smells like maile, a native vine that is frequently used for making lei. Docsity.com 16 Exercise: Examine a fern frond and make a sketch to show the pattern of spores that you see. GYMNOSPERMS Gymnosperm means "naked seed". Unlike the seeds of flowering plants, which are enclosed in a protective fruit, the seeds of gymnosperms are more exposed and unprotected. Many types of gymnosperms produce their seeds in cones, and these types are referred to as "conifers". Pine, spruce, cedar, and fir trees are examples of conifers. There are no gymnosperms native to Hawai'i. All the conifers that you see growing in Hawai'i have been introduced from elsewhere. There is an angiosperm on campus that resembles a conifer, Casuarina (Australian pine Fig 1). The leaves look like needles, but if you look closely, they are segmented. Try not to confuse it with a conifer. Fig. 1 Australian pine Q1. In terms of evolution, which do you think came first: the gymnosperms or the angiosperms? ANGIOSPERMS Noni (Morinda citrifolia) Noni is a Polynesian introduction, brought to Hawai'i on sailing canoes by early Polynesian settlers. Although most people would consider the ripe fruit to be foul-smelling and tasting, it was one of the most important medicinal plants used by early Hawaiian healers. It was used in the treatment of heart troubles, high blood pressure, and diabetes, as well as a poultice and an insecticide. Red and yellow pigments were derived from the bark and roots, respectively, for use in dying bark cloth (kapa). As traditional medical techniques are enjoying a modern resurgence of interest, noni juice and other noni-derived products can increasingly be found in health food stores or ordered off the Web. Docsity.com 17 Q2. Some plants can be very poisonous even in small quantities. Imagine that you are an ancient healer exploring the properties of a plant you are unfamiliar with. How might you begin to determine if it has healing qualities or is poisonous? Breadfruit tree (Artocarpus altilis, `ulu). One of the most infamous stories in maritime history has its origins in the breadfruit tree. In 1787, H.M.S. (His Majesty's Ship) Bounty sailed from England to Tahiti to gather breadfruit plants for transport to the West Indies in the Caribbean Sea as a source of food for slaves. Bounty lingered in Tahiti for five months and the crew " formed attachments with some of the native females, which had considerable influence upon their conduct". Finally departing Tahiti, Bounty was seized by acting lieutenant Fletcher Christian, beginning the most notorious mutiny in sea annals. Putting 16 crewmen ashore on Tahiti, Christian and 8 shipmates, along with Polynesian women and men, sailed to uninhabited Pitcairn Island, where they burned Bounty to escape detection. During the mutiny Captain William Bligh and 18 loyal shipmates were set adrift in an open boat. They rowed and sailed 3,618 nautical miles and reached a Dutch settlement in Timor (in present-day Indonesia) in 41 days, an unparalleled feat of open-boat navigation. In November 1790 the long arm of the British Admiralty sent H.M.S. Pandora to Tahiti to capture the mutineers and bring them to punishment. Fourteen surviving mutineers who were foolish enough to have remained on Tahiti were taken prisoner. After a fruitless search for Bounty, Pandora headed home for England but struck a reef and sank off the northeast coast of Australia. The survivors made their way in 4 small boats to the Dutch settlement at Timor 1,100 miles away, only a third of the distance sailed by Captain Bligh to the same landfall. Of the 14 mutineers taken prisoner, 4 perished in the shipwreck. The remaining 10 eventually stood court- martial in England; 6 were condemned and, of these, 3 were hanged. Murderous warfare flared on tiny Pitcairn between Polynesians and Englishmen soon after their arrival, bringing violent death to all but 2 mutineers. When the next ship touched Pitcairn in 1808, only one mutineer was still alive, patriarch to a flock of women and children. The burned remains of the Bounty were discovered off Pitcairn Island in 1957, and the wreck of the Pandora was found in 110 feet of water in 1977. Breadfruit was eventually brought to the West Indies by Docsity.com 20 Name: WCC Campus Leaf Shape ID Worksheet (Table 2) Location: Time: Date: On WCC campus, investigate leaf shapes. Draw an outline of its shape and vein structure. The ID # should match the drawing in your field book. ID # Leaf Shape Monocot/Dicot (M/D) Docsity.com 21 One possible course of plant evolution. All organisms placed in the plant kingdom are thought to have evolved from ancestral green algae. Docsity.com 22 Modified from: http://www. biology.hawaii.edu/101L/Spring/Manual%20pdf%20201 0/campus%20tour%20lab%205.pdf 3 Docsity.com