# 2.1.1 - anatomy of dicotyledenous plants  (Page 6/6)

 Page 6 / 6

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookplantanat.html

This website provides information on plant structure and support.

This diagram shows the process of secondary thickening in stems

This diagrams shows the annual rings of a tree trunk

## Investigation - tree rings and climate change

Every year a tree forms a new layer of xylem around the trunk. This forms tree rings, which are visible as circles in a cross section of a tree that has beencut down. Each tree ring, or wood layer, consists of two colours of wood; light wood that grows in spring and summer and dark wood that grows in autumn andwinter. Tree rings can be counted to give you a rough estimation of the age of a tree. Occasionally a tree will form many rings in one year or miss formingrings in a year. The width of tree rings is greater in years where good growing conditions occur. In years with droughts or low temperatures, the trees willproduce smaller rings. Therefore, by looking at the tree rings you can get an idea of the weather affecting a tree in a particular year. Scientists can usethis information to help determine the weather patterns of the past as well as events such as forest fires, earthquakes and volcanic eruptions. The study ofpast events using the growth rings of trees is known as dendrochronology (“dendros” = tree, “chronos” = time).

Aim: to observe annual tree rings to assess age and climatic conditions

1. Find a cut or fallen tree, and count the tree rings, starting with the innermost ring. Measure the width of each ring using a ruler, or make a note ofwhether a ring is narrow or wide. Make a note of any scars caused by events such as fires or pests.

2. Draw a bar graph showing the width of your tree rings for every year of the tree's life.

3. How old is your tree? What can you say about the climatic conditions throughout the life of your tree?

http://www.classzone.com/books/earth_science/terc/content/investigations/es2905/ es2905page01.cfm

This is a link to an online tutorial about counting tree rings.

http://www.arborday.org/kids/carly/lifeofatree/

This is a link to a great cartoon video about the different tissue layers in trees (xylem, phloem, etc) and the formation of tree rings.

http://www.worsleyschool.net/science/files/tree/rings.html

This is a link to a good website about tissue layers in trees.

## Economic importance of plant support tissues

Plant support tissue supplies with two important resources namely wood and fibre . Xylem is a source of wood and the sclerenchyma is a source of fibre.

Of course in order to obtain wood and fibre we need to cut down numerous trees. This is called deforestation . Deforestation has escalated in the recent years due to the growing need for wood.

Activity

Collect data showing the area covered by forests in the years 1990 and 2010. Find this data for the following countries: South Africa, Europe, Asia, Northand Central America and South America.

Divide the class into two teams. One group will argue the need for us to cut down trees and the other will be responsible for convincing us thatdeforestation must be reduced dramatically.

## Indigenous knowledge

Making paper, flax, cotton, sisal. Traditional use of fibrous plants by san bushman using sansevaria to make rope etc. thatching. Can we please get helpwith this?

## Internal structure of the dicotyledonous leaf

Refer to chapter 1 to remind yourselves of the internal structure of a dicotyledonous leaf.

This diagram shows the movement of water through a dicot leaf.

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
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
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
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
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
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?
what is a peer
What is meant by 'nano scale'?
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 ?
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
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
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Good
why and for what was five kingdom of classification of organisms introduced
give the ans as fast as possible
SUBHIKSHA
Comment on the ozone depletion over the period of 1982 to 1996