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Plants: Roots, Stems, Leaves, seeds and Flowers. Why are Plants so Important?. Produce oxygen Take out carbon dioxide from our world Can be used to make medicine Can be used as shelter Make food (so we have energy) Can make paper, desks, walls, etc. Parts of a Plant.
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Why are Plants so Important? • Produce oxygen • Take out carbon dioxide from our world • Can be used to make medicine • Can be used as shelter • Make food (so we have energy) • Can make paper, desks, walls, etc
Label all parts of plant • Words to use: • - Root - Flower • - Stem - Fruit • Leaves - Seeds
Roots – 2 types a) Taproot b) Fibrous Example: Carrots, Turnips Examples: Corn, Beans
Functions of ROOTS • Anchors to hold plants in place • Absorb water and minerals • Transport water and minerals to stem • Sometimes used for food storage
How Can Plant Roots Get Damaged? • Adding chemicals to soil (pesticides, chemical waste, etc) • People cutting down trees – chopping off the roots • Putting salt on roads – salt ends up in the Earth/soil • Forest fires (destroy plants and their roots)
What happens when a plant’s roots are damaged? • Plant will not grow and die
What makes the roots grow downwards? • A hormone inside the plant called ‘gravitropism’ makes the roots grow downwards
Functions of Stems • To hold leaves up to the sunlight • To transport materials between roots and leaves • Food Storage (Example: Irish potato tubers) • Protection (Example – thorns) • Can be used to create new plants • Can carry out photosynthesis (if stem is green – like cactus plant)
Stems – 2 types a) Herbaceous b) Woody Example: Tulips Examples: Trees and shrubs
Annual Rings • Each year an ‘annual ring’ forms • Scientists count up these annual rings and determine the age of the plant. • Scientists examine the thickness of these annual rings to determine the length of the growing season (i.e. how long summer was, etc)
How Can Plant Stems Get Damaged? • People/animals cut down trees • Harsh weather (like snow, high winds, floods) can break off branches • Acid precipitation • Forest fires
What happens when a plant’s Stems are damaged? • Transport of food/water to leaves does not happen – can lead to plant death • Plant not supported properly – so plant falls over • No photosynthesis in green stems
What makes the Stems grow Upwards? • A hormone inside the plant called ‘gravitropism’ makes the stems (shoots) grow upwards
Main Functions • Primary site of photosynthesis • Must be able to: • Capture sunlight • Be able to carry out gas exchange • Prevent dehydration • Regulate water loss by opening and closingguard cells • Storage (for food and water) • Support (like for the tendrils on grape vines)
If carrying out photosynthesis was the main function of leaves, then why aren’t all leaves very wide? If leaves were too wide, then leaves would dry out too quickly
How Can Plant leaves Get Damaged? • Insects eating them • Pesticide usage on them (can burn the leaf or prevent photosynthesis) • Acid rain (chemicals) can burn the epidermis of the leaf • Forest fires and natural disasters can kill plants
What happens when a plant’s leaves are damaged? • No photosynthesis can occur • This means: - no oxygen being made - no food being made by plants (so - animals that eat plants cannot, so they die)
Seeds vs. Spores • Seeds – have genetic information and nutrition (fleshy part) • Spores – only genetic information (no food or nutrition, no fleshy parts)
Main Function of Seeds/Spores • To hold genetic information and create new plant
Parts of a Seed • Seed cover – protects embryo • Embryo - little plant - contains food to nourish plant • Seed leaves (cotyledons) - provide the necessary food energy until roots and true leaves form.
How Can Plant Seeds/spores Get Damaged? • Humans touching them and destroying them • Acid rain • Chemicals being thrown onto plants • Too much heat/cold
What happens when a plant’s Seeds/spores are damaged? • Plant will not grow
Main Function of Fruits/Flowers • To help plant produce a new plant (help hold and protect genetic information and later on get the seeds/pollen/spores out)