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Natural sciences

Grade 9

Plants: structure, including genetics

Module 27

Plant organs: roots

Plants live and grow unobtrusively and we are often unaware of the marvels that are hidden within them. We need to take a closer look to understand how miraculously they function.

A plant consists basically of four kinds of organs: roots , stems , leaves and flowers.

Activity 1:

to identify the organs of a plant

[LO 2.2]

Assignment 1:

Complete the tables by supplying the missing information about the different organs.

Plant organ
Above ground/Underground
Main function

Activity: 2

To determine how the structure of a plant stem is related to the functions that it performs

[lo 1.2, 2.4]

Plant roots

Assignment 1:

Go to the garden or the school playing fields and collect one small example of each of four kinds of common plants. Choose weeds, if possible. Ensure that you remove the plant with its root system intact. Rinse off any soil and arrange the plants on a sheet of clean paper.

Do you observe any noticeable differences with regard to the root system?

If you are lucky your plant samples will have two different kinds of root system. Sketch the two main types of root system. Your educator will provide the necessary guidance.

The TWO types of root system are known as the ADVENTITIOUS ROOT SYSTEM and the TAP ROOT SYSTEM .

Plants that have a taproot system have a main root that grows deep into the soil. Most of the plants that survive for more than a year (perennials) have a taproot system. This type of root system can reach water that is far below the soil surface and can anchor the plant. High trees and shrubs and bushes need such root systems. They belong to the group DICOTYLEDONS . They develop from seeds that have two seed leaves or cotyledons, like the seed of the bean plant. Many dicotyledonous plants, of course, are also annuals, but they do have taproot systems.

Monocotyledons, e.g. grasses and maize plants, are annuals. As they grow for one season only, they do not need very deep root systems. They actually need a wide, shallow root system to absorb all the moisture that might reach the soil. MONOCOTYLEDONOUS plants have adventitious root systems and develop from seeds that have one cotyledon, e.g. a maize kernel.

A taproot system consists of one main root, the taproot, and lateral roots that grow from it.

An adventitious root system consists of equally sized roots that grow from the base of the stem and are called adventitious roots . These roots are not branched.

Assignment 2:

Provide the correct labels for the sketches of the two types of root systems.

1. Which type of root system would you find with petunias, which are annuals?

2. Why do petunias develop this type of root system?

3. Which type of root system would an oak tree have?

4. Why would a tree need this type of root system?

5. Do trees have adventitious roots? Provide an explanation for this.

6. Can lateral roots develop from adventitious roots? Explain your answer.

7. Explain the main functions of roots.

Assessment of Root systems

Were you able to distinguish different types of roots and apply your knowledge?

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 9. OpenStax CNX. Sep 15, 2009 Download for free at http://cnx.org/content/col11069/1.1
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