Plants - peelschools.org

twoeggfinnishΒιοτεχνολογία

14 Δεκ 2012 (πριν από 4 χρόνια και 8 μήνες)

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They’re green.






They can’t move.


Why are plants green?



CHLOROPHYLL


Pigment used for photosynthesis



TWO main systems:



Shoot system


Stem, leaf, flower


Root system


Roots


Unlike animals, which are made up of many
systems


Plants can make their own food (no need for
digestive or musculoskeletal system to obtain
food)



But they still need to:


Exchange gases


Move water and nutrients within their bodies


Reproduce


Appr
. 75% of modern medicines come from
plants!



Examples:


Aspirin (Birch bark)


A tree sap that speeds healing


A compound that treats malaria



Right now many plants species are disappearing
before they can be studied.


Absorb water and minerals, store food,
anchor plant



What are some root vegetables? (The ones
where we eat the root, and not the shoots.)



2 main functions:



Conduct photosynthesis


Where?


How? Which organelle is involved?


Which leaves do we eat?



Produce flowers


What are flowers for?


Pollen = plant sperm


Ovary = contains eggs


After pollination (fertilization of eggs by pollen),
seeds are formed. Sometimes surrounded by
fruit. What might a fruit be for?


Occurs with the help of wind or animals.


Ex. insects, bats, birds


Trunks of trees



Contains vascular tissue connecting leaves
flowers, fruits to roots



Sugar cane, wood/paper, cork, linen (i.e.
COTTON)


3 main types:



Dermal tissue system


Outer surfaces of plant parts



Vascular tissue system


Tissues that transport water and nutrients



Ground tissue system


All other structures

Epidermal tissue


layer of cells covering all non
-
woody surfaces
of plant



Periderm

tissue


tissues that produce bark


Xylem:


Transports water and minerals UP from roots to
stem and leaves


Mature cells not alive



Phloem:


Transports nutrients, sugars, hormones, and
water throughout the plant; UP and DOWN


Mature cells alive


Meristematic

cells


Undifferentiated plant cells that can form any
kind of specialized tissue


Located at tips of roots and shoots (areas of rapid
growth)


Xylem rings show each
year’s growth


Outer lateral
meristem

(cork cambium)


Inner lateral
meristem

(vascular
meristem

=
makes new phloem)


There are lots of fields that study plants.



Example


Ethnobotany



the study of how indigenous (native)
plants are used by different cultures


Economic botany
-

plants with commercial
importance. Economic botany includes the study of
harmful and beneficial plants and plant products.


Biotechnology


genetic engineering of plants


Natural resource management


responsible use of
and protection of natural resources