Presentation on theme: "Topic 2 The World of Plants"— Presentation transcript:
1Topic 2 The World of Plants Standard Grade BiologyTopic 2 The World of PlantsRevision presentation for Mammalian Physiology and behaviour.Recap on main points of specification, and on what pupils should still be able to recall from KS3 and KS4Next slide to summarise the topic before going into detail on each one.
2B- Growing plants (Pollination, Fertilisation, Asexual reproduction) World of Plants is divided into:A- Introducing plantsB- Growing plants (Pollination, Fertilisation, Asexual reproduction)C- Making food
3The life cycle of a plant There are 7 stages in the life cycle of a plant.seed / fruit Formationseed dispersalfertilisationpollinationgerminationflower formationdevelopment
4Seed Structure Parts are: Seed coat Forms a tough protective layer Embryo shootEmbryo – grows into plantSQA-List the functions of 3 main parts of the seed of a dicotyledon ie. seed coat, embryo, food storeFood storeProvides the embryo plant with food.Embryo root
5Seed DissectionUsing a scalpel, carefully dissect your seed in half lengthways.Draw a diagram of what you can see.Identify the parts,and label your drawing(workbook p13).
7Investigation: Germination This is an Exam Board Investigation that makes up part of your Practical Abilities grade (20% of finals)Planning may be done in small groups but after this you must work on your ownWrite in your Investigation booklet.
8What affects germination? 3Bio2 Brainstorm 16/03/07Spacing / number of seedsHumidity / water volumeType of seedsSize of seedsType of soil / massTemperatureDepth of plantingGases / oxygen levelsMeasure by % germination after set time
9Germination and Temperature Example of results table. Also draw a graph.What conclusions can you draw from your experiment?How could you have improved it?TemperatureoCNo. of seedsNo. of seeds germinatedPercentage germination4252050
10Germination conditions Germination is the development of a new plant from the embryo in a seed.Seeds need certain conditions to germinate:Waterto activate enzymes which digest stored foodOxygenNeeded for the production of energy for germinationWarmthNeeded for the enzymes to work effectively.SQAOutline the effect of temperature, and availability of water and oxygen on germinationDescribe the changes in percentage germination that occur over a range of temperatures
11Germination and Temperature The best temperature for germination of a species of plant is known as the optimum temperature.The optimum temperature is normally between 15oC and 30oC.
14Carpelfemale parts Stigma Petals Style Stamen male parts Anther Ovary FilamentSQA-List the functions of the parts of flowers i.e. sepal, petal, stamen, anther, stigma, ovary, nectaryOvulesNectariesSepalsCollect a cut-out flower, colour it in and put it together.
15What do the parts do? Sepals- protect the flower when it is a bud Stamen- anther produces male sex cells (pollen)Carpel- stigma traps pollenStyle is where pollen tube grows down to female sex cells.Petals- colourful to attract the insectsBotanical gardens booklet 1- flowers and pollination (blue)Nectaries- give out sugary liquid to attract insectsCarpel- ovary produces female sex cells (ovules)
16Quick Test Why is the seed coat important? Name the parts of the embryo plant.Why is the food store in a seed important?Name the three factors required for germination.Where are a plant’s sex organs found?Name two parts of a flower that attract insects.Name the male part of a flower.Which part of the flower contains ovules?Which part of the flower produces pollen?Which part of a flower catches pollen grains?
17PollinationPollination involves the transfer of pollen (male gamete) from the anther to the stigma (outermost female part)If it is in the same flower it is calledself-pollination.If between different flowers it is calledcross-pollinationPlants are pollinated by insects or the wind.
21Pollination Activity Look at the Botanics Posters Which features are from wind pollinated or insect pollinated plants?Workbook p28Construct a table to show the differences between insect and wind pollinated plants.B
23Hayfever World of plants workbook G – pages 34 &35 C- pages 36 & 37 Answer Q 1 – 5 on hayfeverandAnswer Q 1 – 5 on pollenin the air from Feb - Sept
24FertilisationFertilisation involves the fusion of the nucleus of the male gamete (in the pollen) with the nucleus of the female gamete (in the ovules).Botanical gardens booklet 2World of plants –fruits and seedsgreen
25FertilisationSQA-Describe the growth of a pollen tube and fusion of gametesSQA- Describe fertilisation and fruit formationBotanics fruit formationTomato- juicy fruitBean- podSycamore- small dry nutHazelnut- hard outer wallBotanics infoPollen tubes measured were 6, 9, 11 cm long!!
26Pollen tubes The pollen grain grows a tube. The tube reaches an ovule. The gamete nuclei fuse (fertilisation) and a zygote (seed) forms.
28FertilisationOnce fertilisation has taken place the zygote (fertilised ovule)becomes a seed, and the ovary becomes a fruit.The petals die and fall off.The plant seeds are in the fruit.Soft and juicy- tomato, plum and appleHard and dry- sycamore, dandelion
29What are fruits like? The fruits can be: - soft & fleshy - hard & dry What fruits can you think of?What are their seeds like?Draw a table with headings for each type and write some examples for them.
30Types of FruitsSoft & fleshyHard & dryAppleTomatoHazelnut
31Seed Dispersal- why?Seeds must be carried away (dispersed / scattered) from the parent plant to:Reduce overcrowdingReduce competition for:- Water- Light- NutrientsBotanical gardens booklet 2World of plants –fruits and seedsgreen
32Seed Dispersal Dispersal method Description Seeds/ Fruits Wind Seeds are designed to travel as far as possible.May have extensions which act as parachutes or wings.Fruits may be shaken like a pepper pot.SQA-Give one example for each of the following different dispersal mechanisms: wind, animal – internal, animal - externalPlus water but rare and don’t need to know about it.Water- seeds float and can travel for miles down rivers and into seaParachute/wings- sycamore, dandelionPepperpot- poppyBotanicsAnimal externalMule grab- wool/hair, trample burr-foot, hooked burr-wool, mistletoe-beakAnimal internalBrightly coloured to attract animalLike to eat as sweet, nutrient sourceSeeds pass through stomach must be able to resist acidWindSycamore 110cm, dandelion 163cm, elm 50cm, pine 79cm (by throwing seeds in air?)
33Seed Dispersal Dispersal method Description Seeds/ Fruits Animal (internal)Fruit is brightly coloured to attract animals.When eaten the seed travels with the animal, survives acidic digestive juices and is passed out in the faeces.SQA-Give one example for each of the following different dispersal mechanisms: wind, animal – internal, animal – externalExamples animal internal- Cherry, tomato
34Seed Dispersal Dispersal method Description Seeds/ Fruits Animal (external)Some have little hooks or sticky substances so they stick onto the animal’s fur, are carried away and rubbed off later.Some carried away by animals and dropped.SQA-Give one example for each of the following different dispersal mechanisms: wind, animal – internal, animal – externalanimal externalMistletoe has a sticky substance on the outside.Hooks on outside- burdockCarried and dropped- hazelnuts
35Activity Wind Animal (external) Animal (internal) Cut out the seeds, match and stick them into appropriate columns in a table, for:WindAnimal (external)Animal (internal)Photocopied handout of seed to cut and stick.[There is also mechanical (eg broom, sea cucumber) and water (eg coconut) but you don’t need to know them for Standard grade]
36Activity Listening exercise on seed dispersal Listen to the tape, Use the commentary to help you answer questions on your handout.File in box in animal house with polypocketed commentary (white paper) of tapeWorld of Plants Workbook p41Comparing Lime and Sycamore seeds.Go through the problem solving activity
37Quick Test-A What term is used to describe male and female gametes? What is pollination?Name the two types of pollination.Describe the differences in the pollen between insect and wind pollinated plants.Explain why the stigmas of wind pollinated flowers hang outside the flowers.
38Quick test-B Why do wind pollinated flowers not produce nectar? How does the male gamete reach the female gamete?What is a fruit?Name three ways in which fruits and seeds are dispersed.Why is it important that fruits and seeds are carried away from the parent plant?
39Types of reproduction Sexual reproduction Involves 2 parents and sex cells ie. pollen and ovule join to make a new individual.Asexual reproductionInvolves 1 parent and no sex cells.Ways they naturally reproduce include:- Tubers- ( Bulbs )- RunnersSQA Describe asexual reproduction by runners and tubersBotanics book 3 asexual reproductionYellow
40TubersTubers are underground food stores which stores food over the winter and provides a new plant with food until it can make its own.Examples: potato, artichoke, yam, cassava, water chestnut, arrowrootTuber info fromTaro- Japanese potatoFood made by the new plant is sent to make new tubers. Thereby reproducing itself.
41Arrowrootarrowroot = arrow root = Chinese potato (this name also is used for jicama) = goo = seegoo = arrowhead = Chinese arrowhead = tse goo = ci gu = tsu gooNotes: The name arrowroot is more commonly associated with a thickener that's made from the plant.A fresh arrowroot tuber looks like a small onion, only without the layers.It should be peeled, and then it can be boiled or stir-fried.Look for it in Chinese markets during the winter.
42Cassavacassava = casava = manioc = mandioca = tapioca root = yucca = yucca root = yuca root = Brazilian arrowroot Pronunciation: kuh-SAH-vuhNotes: People in Hispanic countries use cassavas much like Americans use potatoes. There's both a sweet and a bitter variety of cassava. The sweet one can be eaten raw, but the bitter one requires cooking to destroy the harmful prussic acid it contains.
43Topinambour tapioca root Topinambour Water chestnut Chinese water chestnutNotes: Water chestnuts are delightfully sweet and crisp- if you buy them fresh. You need to peel off their brown jackets and simmer them for five minutes before stir-frying.Tinned Water chestnuts are easily available but not nearly as good. If you use them, blanch them first in boiling water for thirty seconds. ACTIVITYWORKBOOK p 39 Growing potatoes PS
44BulbsBulbs are also underground food stores which work in the same way as tubers.The difference is that bulbs have thick fleshy ‘leaves’.Keukenhof gardens near Amsterdam Holland.
461. Sept.- Oct. Planting Time The tulip bulbs are going to be planted twice as deep as the bulb is high. They have no roots at this stage.2. November Making Roots The roots start growing out of the base, establish themselves taking nutrients from the soil. Mother bulbs get ready for winter.4. Feb. – March Growing Period The bulbs begin to change as the starch, or carbohydrates in them turns to sugar. As this occurs, the leaves and flower gradually push up-wards out of the bulb.5. April – May Blooming Time The tulips are in bloom-they receive their nourishment from the roots-only the brown skin of the bulb remains as all of the energy has gone to the bloom.6. May – June Regeneration After flowering the blooms are cut and the leaves are left on the plant. The new daughter-bulbs use the food in the leaves to grow.7. July - Sept. Multiplying Up to five small bulbs can be expected to grow out of the mother bulb. They form their roots slowly, and develop their blooms and leaves within the bulb, for next year's plant.Source3. Dec. - Jan.Cooling Period Rest period. In order for bulbs to bloom in the spring they need weeks of at least 5oC. Frost at this time doesn’t harm them.
47Runners Runners are side shoots which grow out from the parent plant. Buds form at points along the runner and eventually these buds form roots and grow into new plants.Examples: spider plant (Anthericum), strawberry (Fragaria x ananassa)
48Collect Information Card “Asexual Reproduction” Flame violet(Episcia reptans)Info card in box file in animal house- blue sheet polypocketed.Collect Information Card“Asexual Reproduction”Take short notes from it.
49World of plants workbook ActivityWorld of plants workbookRead p20“Advantages of asexual reproduction”Read p32 & 33.Copy and complete the table.Summarising advantages & disadvantages of sexual versus asexual reproductionSQA- List the advantages of both sexual and asexual reproduction to plants
50Reproduction- advantages AsexualSexualGenetically identical offspring (clones) which have parent’s strong characteristics (but weak ones also passed on) and are suited to their environment.Narrow distribution spreading over the area quickly as no vulnerable stages involved.Genetically different offspring- variation.More chance of survival if conditions change.Wide distributionReduces competition for water/light/nutrients as no dense growth around the parent.Using seeds allows the offspring to travel to new areas.
51ClonesA clone is the name given to the genetically identical plants produced from a single parent plant.They are formed during asexual reproduction only.SQA- State what Is meant by the term “clone”
52Artificial Propagation People can make use of plants’ ability to reproduce asexually (instead of using seeds) by using methods of artificial propagation such as:- Cuttings- GraftingsAgain this produces genetically identical offspring (clones).ACTIVITYWORKBOOK p40 Dandelion roots PS
53Cuttings They can be placed in moist soil or water (and sometimes Cuttings are small pieces of stem with some leaves attached, the new plant grows from this.SQA- Describe ways of propagating flowering plants artificially by cuttings and graftingsSourcecounties.cce.cornell.edu/.../propagation.htmThey can be placed in moistsoil or water (and sometimesdipped in rootingpowder).
54GraftingA cut stem of one plant (with good flower or fruit growth) (the graft) is taken and firmly attached to the rootstock of another plant (which has a strong, established root system) (the stock).Examples- roses, fruit trees
55Grafting- advantagesAllows you to clone the commercial qualities of a particular fruit variety on another tree. Seed trees have highly variable fruit quality.They come into production much earlier (2-3 years) than trees grown from seed (5-10 years).
56World of Plants Workbook p42 ActivityWorld of Plants Workbook p42The effect of rooting powder on cuttingsCollect some graph paper and work through the problem solving activity
57World of plants workbook p33 ActivityWorld of plants workbook p33“Artificial propagation- commercial advantages”Read page. Collect Information sheetWrite short notes on it.SQA- Explain the advantages to man of artificial propagation in flowering plants
58Commercial aspectsArtificial propagation has allowed us to adapt and improve plants for our own use.Some of the benefits include:Quick production of large numbers of genetically identical plants.ACTIVITYWORKBOOK p42 Air Layering in clematis PSSpecific varieties, desired features or consistent quality can be produced especially in fruit, flowers.
59Quick Test-C One Runners, tubers, bulbs Spider plant, strawberry How many parents are involved in asexual reproduction?Name 3 ways in which plants reproduce asexually.Give 2 examples of plants that reproduce asexually by producing runners.What term is used to describe a population of genetically identical plants?Name 2 common methods of artificial propagation.Give the commercial advantages of artificial propagation.OneRunners, tubers, bulbsSpider plant, strawberryClonesQ from Leckie bookCuttings, graftingQuick method, producing large numbers of plants, of known quality and specific variety
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