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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?

Dicotyledonous leaf

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.

Questions & Answers

what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
Shelly Reply
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu
what's microbiome?
john Reply
Microbiology is the scientific study of microorganisms
Ibra
the microorganisms in a particular environment (including the body or a part of the body).
Ibra
describe the bacterial cell
Akello
The biggest populations of microbes reside in the gut.other popular habitats include the skin genitals.The microbial cells and their genetic material ,the microbiome ,live with human from birth .
Zahreen
can agriculture be integrated into biology
David
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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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