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[LO 1.2, 2.4]

Take a fresh plant with roots, rinse the roots to remove the soil and carefully examine the roots. Are you able to see the fine, hair-like growths at the tips of the roots? They will be particularly visible on bean plants that you germinate from seeds yourself. These structures are known as root hairs, or radical hairs.

What is the function of a root hair?

The following is an illustration of the tip of a root:

Assignment 3:

Explain what happens in each of the following regions:

Root hair region:

owing region:

Root tip:

Root hairs consist of special cells on the outer surface of the root right behind the growing region, which increase the surface of the root so that the maximum amount of water and mineral salts can be taken up from the soil.

Assignment 4:

Make a drawing showing the structure of a typical root hair. Provide your drawing with labels and a caption.

The root hair penetrates the small spaces between the particles of soil to suck up the moisture that is trapped between the soil particles. Then it is the function of the next plant organ, namely the plant stem, to conduct the moisture further.

Assessment: Root hairs

Were you able to draw the basic sketch?

[LO 1.2]

Assessment

LO 1: Scientific investigations:

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

This is evident when the learner:

  • conducts investigations and collects data;

LO 2: Constructing Science Knowledge:

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

This is evident when the learner:

  • categorises information;

2.4 applies knowledge.

Memorandum

PLANT ORGANS: ROOTS

Activity 1

Assignment 1

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

A typical plant consists of the PLANT ORGANS :

Root, stem, leaf and flower

Plant organ
Root
Stem
Leaf
Flower
Above ground or underground
Under
Above
Above
Above
Main function with regard to the plant
Absorbs water and minerals; anchors the plant.
Bears the leaves and flowers, and fruit, eventually, in a way that exposes each organ correctly.
Photosynthesis
Propagation
Above ground or undergroundMain function with regard to the plant
Root UnderAbsorbs water and minerals; anchors the plant.
Stem AboveBears the leaves and flowers, and fruit, eventually, in a way that exposes each organ correctly.
Leaf AbovePhotosynthesis
Flower AbovePropagation

Activity 2

Assignment 1

ROOT SYSTEMS

  1. There are adventitious root systems and taproot systems.
  2. Plants develop one or the other of these systems according to the type of plant that they are (There are two main types).
  3. Plants that survive for more than one year, perennials, require deep root systems for finding water during dry seasons and to be anchored properly. You will realise that tall trees and large shrubs and bushes need such root systems. They belong to the group called DICOTYLEDONS . They develop from seeds that have two seed leaves or cotyledons, like the seed of the bean plant.
  4. Other plants, like grasses and maize plants, annuals, live and grow for one season only and therefore do not need such deep root systems. They need wide-reaching, shallow root systems. These plants belong to the MONOCOTYLEDONS and develop from seeds that have one seed leaf, e.g. a maize kernel.

Assignment 2

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, the adventitious roots .

The life cycle of annuals is completed in a year – they do not need taproots – and they will therefore have an adventitious root system

Trees have a taproot system because they require to be anchored deeply and have to obtain water from deep below the ground.

As adventitious roots grow from stems, they will be of no value for trees that need deep anchoring.

Lateral roots only grow out of other roots.

Main functions of roots:

anchoring

uptake of water

uptake of mineral salts in solution

conducting water to the upper parts of the plant

When a root system is investigated, the following structure can be observed:

Assignment 3

Root hair region: region where root hairs develop

Cell lengthening region: region where cells lengthen and differentiate

Cell division region: where cells divide

Meristem: general region where cell division and cell lengthening occur

Root tip: Protects the sensitive foremost growth tip by keeping it slimy to prevent wear.

  1. A root hair is a special cell on the outer surface of the root – immediately following the growth tip – that is specially enlarged to take up a maximal amount of water and salts from the soil.

The srtucture of the root hair is of importance in further studies in Biology.

Assignment 4

This is what we shall focus on next.

Root hair

  1. The root hair penetrates the small spaces between the particles of soil to suck up all moisture that is trapped between the soil particles. Then it is the function of the next plant organ, namely the plant stem, to conduct the water.

Questions & Answers

what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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
Daniel
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
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
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.
Tarell
what is the actual application of fullerenes nowadays?
Damian
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.
Tarell
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.
Virgil
is Bucky paper clear?
CYNTHIA
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.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor 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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