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Variation: Instead of using one cylinder with water and one with food dye, use two different colour food dyes (e.g. blue and red). At first the flower will showtwo separate colours, but as time goes by the whole flower will show both dyes. This is because water can move sideways between xylem vessels through openingsalong their length. The ability of water to move sideways between vessels is useful for when air becomes trapped in a vessel, causing a blockage. If you cutthe stem right up to the base of the flower, this will limit movement between the xylem vessels.

Variation: Try using celery stalks with leaves. Cut open the celery stalk (cross-section) and you will see that the little holes inside are coloured – these arethe vessels.

An example of this experiment with photographs can be found at: http://www.practicalbiology.org/areas/intermediate/cells-to-systems/transport- in-plants/investigating-transport-systems-in-a-flowering-plant,70,EXP.html

Secondary growth

Meristematic tissue

  • Meristematic tissue consists of small cells that are unspecialized. These cells divide by mitosis to form new cells that can differentiate (undergo changes intheir structure) and can become specialized tissue (e.g. xylem, phloem, epidermal cells)
  • Primary meristematic tissue is found in the tips of roots, stems and buds. When it divides new cells are produced which causes the plant to grow longer. Thisis referred to as primary growth.
  • Secondary meristematic tissue originates from permanent tissue, usually parenchyma tissue which divides by mitosis. Cambium is secondary meristematictissue that is found in roots and stems. When these cells divide by mitosis it results in the plant becoming wider. This is called secondary growth.
  • Every growing season the stem of a plant increases in width – this is known as secondary thickening.
  • Towards the end of the first year of growth, the parenchyma cells between the vascular bundles become meristematic and link up with the cambium tissue toform a cambium ring.
  • The cells in the cambium ring start dividing to form secondary phloem (on the outside) and secondary xylem (on the inside).
  • Each year another ring of secondary phloem and secondary xylem is formed, making the stem grow wider.
  • It is not possible to see the layers of secondary phloem but the secondary xylem are visible. These form rings called annular rings which can be used to workout the age of a plant.
  • As new rings are formed each year, the older rings are pushed inward and the xylem vessels collapse due to the pressure. The wood in the centre becomesdenser and harder than the wood at the surface and is called heartwood.
  • The youngest annual rings found on the outside serve its function of transporting water. This wood is not as dense and is called sapwood.
  • The light-coloured rings are called spring wood. They are formed during spring and summer when the growing conditions are favourable. The rings are thereforerelatively thick and light in colour as the xylem cell walls are thin.
  • The dark-coloured rings are called autumn wood. They are formed during autumn and winter when the growing conditions are unfavourable. The rings aretherefore relatively thin and dark in colour as the xylem cell walls are thick.

Questions & Answers

how can chip be made from sand
Eke Reply
are nano particles real
Missy Reply
yeah
Joseph
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
Lohitha
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
has a lot of application modern world
Kamaluddeen
yes
narayan
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
why and for what was five kingdom of classification of organisms introduced
SUBHIKSHA Reply
give the ans as fast as possible
SUBHIKSHA
Comment on the ozone depletion over the period of 1982 to 1996
Mpho Reply

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Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
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