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Natural sciences

Grade 4

Life and way of living

Module 5

The senses of smell and taste

Activity: To learn more about the senses of smell and taste [LO 2.1]

When you eat, the tongue tastes the taste of the food and your nose smells the flavour. This is how it works:

The openings of your mouth and nose come together in your throat, behind your mouth. The flavours of the food that you eat go to your nose from the back of your mouth. From there, nerves take a message to the brain and the brain tells you what you smell.

The tongue is rough and covered in taste buds to determine different tastes. Write down what the four tastes are that your tongue can identify:

Now pinch your nostrils together with your fingers to close your nose and drink some tea or cooldrink. Why is the taste different?

What have you noticed when you eat while you have a cold?

The sense of smell is very important in the animal world.

Write a proper sentence to say something about the sense of smell of each of the following animals.







Think of other ways in which animals are able to protect themselves because of their sense of smell.

Try this: Ask someone to mark a route with vanilla or vinegar, without you seeing it. Then try to follow the route by depending on your sense of smell!


LEARNING OUTCOME 2: CONSTRUCTING SCIENCE KNOWLEDGEThe learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

ASSESSMENT STANDARD 2.1: The learner is able to recall significant information.


a. sweet

b. salty

c. bitter

d. sour

When the nostrils are pinched together, scents cannot enter the nose, so you will only distinguish sweet, sour, salty and bitter.

In the case of a cold: the same as above.

The sense of smell in the animal world.

Skunk: Protects itself by spraying a strong smelling / pungent secretion in the direction of the enemy.

Jackal: Depends on its sense of smell when hunting. It also has scent glands that secrete scent as it goes along and helps it to find the way on its return.

Dog: Smells very well. Because of their well-developed sense of smell, dogs are used to sniff out drugs, explosives and even people in crowds. They also use their sense of smell when they are hunting.

Antelope: Uses its sense of smell to stay out of danger. If they smell an enemy, antelopes run off very quickly.

Rhinoceros: They also have scent glands underneath their feet to leave messages for other rhinoceroses.

Hoopoe: Birds usually keep their nests very clean, but not the hoopoe. Part of its defence mechanism is to not clean the nest so that the smell will keep predators away.

Questions & Answers

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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
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 4. OpenStax CNX. Sep 18, 2009 Download for free at http://cnx.org/content/col11096/1.1
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