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UNIT 1 - Area of Study 2: Functioning organisms. The common requirements of living things are; Energy Gas exchange Water & nutrients Removal of wastes Reproduction. Name: Class: . AUTOTROPHS. Meristematic tissue. Cells that undergo cell division
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UNIT 1 - Area of Study 2: Functioning organisms The common requirements of living things are; • Energy • Gas exchange • Water & nutrients • Removal of wastes • Reproduction Name: Class:
Meristematic tissue • Cells that undergo cell division • Usually found in the roots and shoots of plants • Referred to as meristems
1. Dermal tissue • Cover surface of plant • Protection from cuts and microorganisms • Epidermis: protects plant body • Cuticle: prevents water loss • Root hairs: aid water and mineral absorption
Dermalstoma, trichomes, & root hairs http://www.ucd.ie/botany/Steer/hair/roothairs.html
2. Ground tissue • Internal cells • Storage, support and photosynthesis
3. Vascular tissue • Conducting tissue • Transports substances • Xylem • Transports water • Dead cells • Phloem • Transports “phood”: sugar • Living cells
Phloem • Sieve tube cells: • Have no nucleus, mitochondria or vacuole. • Cytoplasm is free flowing between pores at ends of cell wall. • Pores allow for a channel which sugars flow through. • Companion cells: • Found beside sieve cells. • Have a nucleus and other organelles to help control sieve tube cells.
Vegetative Organs • Roots • Stems • Leaves
Function of roots • Anchor the plant • Absorb water and minerals from soil • Storage of glucose • Zone of cell division • Zone of cell elongation • Zone of maturation
Tap roots: large tapering main root moves vertically • Fibrous roots: smaller roots of equal size, don’t go deep but hold soil in place • Roots provide surface area for water to be taken up. • Surface area increased by root hairs. • Water enters through osmosis. • Root pressure is a force pushing water up. • Minerals are actively transported through specific channels in the root cell plasma membranes.
Many plants have root nodules, which contain nitrogen-fixing bacteria. • The bacteria enter the root hairs from the soil and infect the root, causing it to swell into a nodule. The nodule is well connected to the plant transport systems and the bacteria are contained within the root nodule cells. • Nitrogen-fixing organisms make life possible by providing nitrogen in a form that they, and other organisms, can use. • Nitrogen is required in large amounts because it is a component of all proteins.
Function of stems • Support leaves to maximize light absorption • Part of a channel for transporting water, minerals, and organic solutes • Adhesion and cohesion allow continuous movement of water through plant in xylem tissue. • Storage of glucose
The continuous movement of water through the plant is known as the transpiration. • Translocation is the movement of sugars in solution through the plant. Sugars, usually in the form of sucrose, are actively transported against a concentration gradient (from high to low concentration) into the sieve cells. This requires energy. The energy for this comes from respiration occurring in the mitochondria of the companion cells.
Function of leaves • The continuous movement of water through the plant is known as the transpiration. • This constant upwards movement is driven by the evaporation of water from the leaves. • Storage of glucose.
Leaves are also the MAIN photosynthetic structure. • Many leaves have a distinct upper and lower surface. • The cells containing chloroplasts (mesophyll cells) are localised under the upper (dorsal) surface to receive the most sunlight. • Their stomata are found on the lower (ventral) and cooler surface to reduce the loss of water. • http://www.youtube.com/watch?v=0IJMRsTcwcg&feature=related
Systems – Heinemann Biology • Energy • Soil • Photosynthesis • Mycorrhiza • Nitrogen-fixing bacteria • Carnivorous plants • Gas exchange • Epidermis • Stomata • Diffusion • Transport system • Transpiration • Adhesion/cohesion • Translocation • Xylem • Phloem • Vascular bundles • Waste removal • In leaves • Dropping leaves & limbs • Dissolving in vacuoles • Resins, waxes, etc
AUTOTROPHS KEYWORDS The basic structure of a plant comprises stem (for support), leaves (for photosynthesis) and roots (to anchor into the soil).
Digestive Systems • Mechanical digestion • Chemical digestion • enzymes • Ingestion • Digestion • Absorption • Egestion • Varies with differing diets
http://science.nationalgeographic.com/science/health-and-human-body/human-body/digestive-system-article/http://science.nationalgeographic.com/science/health-and-human-body/human-body/digestive-system-article/ • http://bio-animations.blogspot.com.au/2008/04/human-biology-digestive-system.html
Herbivore – Foregut fermentation Herbivore – Hindgut fermentation Carnivore Omnivore Koala
O2 by diffusion