<< Chapter < Page Chapter >> Page >

[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

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
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
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
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
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
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
Smarajit Reply
Privacy Information Security Software Version 1.1a
Good
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!





Source:  OpenStax, Natural sciences grade 9. OpenStax CNX. Sep 15, 2009 Download for free at http://cnx.org/content/col11069/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Natural sciences grade 9' conversation and receive update notifications?

Ask