(Objectives from the Kenya Institute of Education) Science- Plants Standard 6,7,8

Transcription

1 Plants Objectives: Draw and label parts of a flower Classify plants Classify crops Describe pollination and fertilization (meaning and fusion) Draw and label parts of a seed (monocot and dicot) Name weeds and control of weeds Name external plant parts and their function (roots, leaves, flower) Investigate conditions necessary for germination Explain interdependence between plants Explain interdependence between plants and animals Explain what a food chain is Explain meaning of crop pests Identify some crop pests, their effects and control measures Explain how plants are adapted to their environment (dry areas, wet areas) Identify signs of unhealthy crops State effects of crop diseases Vocabulary: Interdependence: support, habitat, shade, food, oxygen, co2, shelter, pollination, medicines, nutrients, animal waste, decomposition, food chain (max. 4 members), unhealthy (stunted growth, discolouration on growing leaves/ears/stems, curled leaves, wilting, spot/streaks) Crop pests: aphids, cutworms, stalk borers, weaver birds Storage pests: rodents weevils, white ants; effects (reduced yields, quality, transmission of disease); control (scaring, trapping, hand picking, weeding, spraying, pruning) Control measures: scaring, trapping, hand picking, weeding, spraying, pruning

2 Cereal crops Maize, millet, Food crops sorghum, oat, wheat, rice Cash crops Oily crops Sunflower, sim sim, coconut, macadamia, castor oil, avocado Leguminous crops Bean, peas, groundnut, green grams, black bean, etc Fruit crop Orange, mango, passion, pawpaw Tubers Cassava, sweet potato, carrot, beet root Fibres crops Cotton, flax, sisal, palm Beverage Tea, cocoa, coffee, barley Stems Irish potato, yams, ginger, crocus Plants 1. Categorize a. Crops i. Cash crops ii. Food crops b. Weeds: unwanted plants i. Ex: oxalis, mexican marigold, pig weed, black jack, thorn apple, wandering jew ii. Effects 1. Compete for space, sunlight, mineral salt, water 2. Provide hiding for pests 3. Spread disease to crops iii. Controls 1. Digging them out, slashing, mulching, uprooting, flooding, use of herbicide 2. Classify (Use a Plant Flow Chart/ graphic organizer) a. Non-green/non-flowering (e.g. Fungi) i. Penicillin, puffball, toadstool, yeast, mould, mushroom b. Green i. Flowering 1. Mono-cot a. Millet, sorghum, rice, wheat 2. Di-cot a. Maize, bean, peas ii. Non-flowering 1. Algae, lichen, moss, fern 3. Plant parts a. Roots (2 main types) i. Fibrous 1. Monocot plants 2. E.g. Maize, millet, sorghum, wheat ii. Tap 1. Dicot plants a. E.g. Beans, peas, green grams iii. Others (modified)

3 1. Breathing root - absorbs 2. Clasping root - offers support 3. Prop root - support monocot plants 4. True aerial root - absorbs moisture in air iv. Function 1. Absorbs water and mineral salt 2. Stores food in some plants 3. Support plant (e.g. Strong wind) b. Leaves i. Simple ii. Compound iii. Function 1. Manufacturing plant food by photosynthesis 2. Carrying out transpiration through stomata 3. Stores food in some plants c. Flower i. Parts 1. Sepals (Calyx) - offers protection at bud stage 2. Ovules - female gamete, becomes seed when fertilized 3. Filament - hold anther in upright position for pollination 4. Anther - produces male gamates (pollen grain) 5. Style - holds stigma in upright position for pollination 6. Stigma - receives pollen grain 7. Petal (corolla)- attracts insect for pollination ii. Pollination 1. The transfer of pollen grains from anther to stigma i. Self pollination - transfer of pollen grains in same flower (or different flowers in same plant) ii. Cross pollination - transfer of pollen grain to stigma of a different plant of the same kind 2. Agents of pollination a. Wind pollinated flowers i. No smell (scent) ii. Dull coloured petals iii. Small flowers iv. Loosely attached anther v. Stigma hangout in the flower vi. No nectar produced b. Insect pollinated flowers i. Strong scent ii. Coloured petals iii. Large flower iv. Firmly attached anthers v. Stigma are in the flower (short) vi. Produce nectar 3. Process of fertilization a. Fusion of male gamete and female gamete resulting in formation of seed and fuit 4. Stages of flower fertilization a. Pollination b. Germination of pollen grain into pollen tube c. Development of pollen tube through the style d. Fusion of male nucleus with female nucleus in the ovary e. Formation of fruit from ovary iii. Seed/fruit

4 i. Needed for germination: Air (oxygen), warmth (right temperature), water (moisture) ii. Has two scars fruit Formed from ovary Has one scar seed Formed from ovules iv. Crop pest Covered by pericarp Covered by testa Field pest Storage pests Others Attacks crops in the shamba Attacks crops in the store Locusts - eat green parts of plants Examples: Aphids - suck sap Stalkborer- bores holes in stalk Cutworm - cut young seedlings on the stem Examples: Weevil - make hole on grains Rat - eat grains Moths- eat grains 1. Effects a. Transmit disease b. Reduce crop yields (quality and quantity) c. Economic loss 2. Controlling pests a. Use of pesticide b. Use of scarecrow c. Pruning and weeding d. Use of predator (biological) v. Signs and effects of unhealthy crops 1. Signs a. Discoloured leaves b. Distortion of fruit c. Wilting and/or curled leaves d. Stunted growth e. Spots or streaks f. Malformation 2. Effects a. Reduced yield and quality b. Transmission of disease to other plants and/or man c. Economic loss vi. Adaptation -adjustment features in plants that make them survive in its habitat 1. Wet - hydrophytes 2. Dry - xerophytes Army worm - eat leaves Birds (weaver, quelea, sudan dioch) eat grains Moles (rodent) eat tubers, etc. Name Examples Characteristics

5 Wet areas hydrophytes Water lily, aquatic fern, mangroves, water hyacinth, rice, arrow root Broad leaves Shallow roots Thin cuticle Many stomata Flexible stems Air sacs Floating flowers Dry areas xerophytes Cactus, baobab, acacia, sisal, euphorbia, candelabra Narrow leaves Deep roots Few stomata Succulent stem Folded leaves Shiny hair to reflect sunlight