2.1 2.1 Plant Cells, Tissues and Organs How do the cells of a seed become different parts of a plant?
Specialized Cells and Tissues in Plants Tissue: Organ: Meristem cell: Meristematic cells are constantly producing more cells which become specialized These cells become _______________________________ • Summarize the roles of these tissues in your notes
Repairing & Replacing Specialized Cells Plants are different from animals; plants form new organs throughout their lives (i.e. new leaves) Due to rapidly dividing meristematic cells, plants push upwards, downwards & outwards Bud: Terminal bud: Lateral bud:
Growing up or Branching out? Cells in actively growing areas (terminal bud) give off a hormone called ______________ Auxin causes the lateral buds to be ____________
Plant Organs: The leaf Flowering plants only have 4 organs: A leaf provides a large surface area where ________________ can take place
2.1 Plant Organs: The leaf
Plant Organs: The leaf • Use your textbook (page 61) to define the role of the following parts of the leaf • cuticle, upper epidermis, mesophyll tissue, palisade cells, spongy parenchyma, vascular bundles, xylem, phloem, lower epidermis, guard cells, stomata • Also define transpiration
Plant Organs: The leaf Transpiration: Evaporation of water from leaves Why does a plant transpire?
The Choloroplast Photosynthesis happens in the ______________________ Light energy from the sun combines with CO2 and water to form glucose Glucose (C6H12O6) is a carbohydrate used by plants and animals to store energy 6CO2 + 6H2O + light energy C6H12O6 + 6O2
The Chloroplast Chloroplasts can change their shape and position to capture ___________________ Chloroplasts contain little sacs called ___________ which contain ____________ Thylakoids are arranged in stacks called _____________
The Stem Two functions:______________ and __________________, __________________________ Xylem cells grow to be long, then die leaving their cell walls behind which form pipes that __________________________ Dead xylem cells are fortified with ____________ Xylem cells are grouped with phloem vessels in vascular bundles Phloem cells are porous which allows ___________________(e.g. sucrose) between phloem and cells of the plant
The Roots • 3 functions: Roots hairs: absorb water and minerals Cortex cells store starch Endodermis: Pericycle:
Types of Roots Tap Root Fibrous Root
Plants under attack! Plants become infected by ________________________(just like animals!) Plant diseases are important: multibillion dollar industry, can cause famines, has forced people to move throughout history More than 400 plant viruses known – cause more than 1000 plant diseases! Brown Rust
Plants under attack! Plant Galls: Plants produce galls in response to attack from insects, bacteria, fungi and viruses Some insects lay eggs in plants (oak tree, golden rod) and the larvae develop in the gall Chemicals secreted by insects cause certain genes to be activated by the plant causing production of the gall
The Reproductive Organ: The Flower The only role of the flower is reproduction The flower is just a specialized leaf: one type produces pollen (which makes sperm), while the other produces eggs Most plants accomplish pollination using the wind, animals or insects Colour and scent attracts insects or animals to the plant; pollen is picked up from the male part, deposited on female part After fertilization, seeds are produced which are embedded in fruits