<< 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

can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
is it 3×y ?
Joan Reply
J, combine like terms 7x-4y
Bridget Reply
im not good at math so would this help me
Rachael Reply
yes
Asali
I'm not good at math so would you help me
Samantha
what is the problem that i will help you to self with?
Asali
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris 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
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
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
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!
QuizOver.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