Download Science misconceptions and explanations

Science misconceptions and
explanations
Request
If any errors in the explanations are discovered, please give your feedback for amendments to be made. :)
Misconceptions were selected and complied from the following sources. Common misconceptions
surfaced during testing, fellow educators, internet, and assessment books.
Misconceptions and explanations
A spider is an insect.
According to scientific classification, insects have six
legs but spiders have eight, hence they are not insects.
A whale is a fish.
A whale is a mammal because it gives birth to it's
young alive, and has lungs instead of gills.
Micro organisms are animals
Living things are classified as plants, animals, fungi
and micro organisms. Thus, micro organisms are a
category of living things and not a subset of animals.
Fungi are plants.
Plants are able to make food but fungi don't, so they
are not plants.
Misconceptions and explanations
Objects that move are living things.
The definition of living things also includes the
ability to reproduce, grow, response to stimuli etc. Not
all objects that move will exhibit these characteristics
(examples man-made objects), hence the above is a
misconception.
Hard objects are strong.
Degree of hardness and the strength of a material are
two different aspects. Hardness refers to resistance to
scratches while strength refers resistance to breaking.
Large objects are heavier.
A counter-example to show the above is a
misconception. Children's balloons are larger than a
piece of pebble but they are lighter.
Heavy objects sink while lighter objects float
A ship will float while a small stone sinks. :)
Misconceptions and explanations
The mass of an object is its weight.
Mass refers to the amount of matter in a body. Weight
refers to the force of gravity acting on an object.
(things weight differently (lighter) on the moon
compared to the Earth, but the objects still remain the
same.) :)
"White cloud" coming out of kettle is steam.
The white cloud is steam condensing on the cooler air
as it emerges from the sprout. Hence, it is made of
tiny water droplets. Clouds, mist, fog are water vapour.
Clouds, mist and fog are all made of tiny water
droplets.
Misconceptions and explanations
The body has only 5 systems.
The primary science syllabus only teaches about five body
systems but there are a lot more, for example, the nervous
system.
Food is digested in every part of the body system/large
intestine.
Digestion only occurs in three parts of the digestive
system, the mouth, stomach and small intestine, with the
bulk of the digestion taking place in the small intestine.
The large intestine is responsible for the removal of water
from indigested food.
Misconceptions and explanations
The water carrying tubes and food carrying tubes are only
found in the stem.
Water carrying tubes and food carrying tubes are found all
over the plant. The stem is the part of the plant that
connects the other various parts together and hence is like
"a highway that links small roads together."
"Coldness" travels from a cold object to a hot object.
There is no such term as coldness in science. Heat flows
from objects of higher temperature to objects of lower
temperature.
Misconceptions and explanations
Heat is temperature.
Heat is a measure of the amount of energy in an object
while temperature is the degree of hotness. An analogy.
Imagine two piggy banks. One has a dollar note while the
other is filled with 100 ten cent coins. The dollar note is
of higher denomination than a ten cent coin (temperature).
In terms of total amount (energy), the piggy bank with 10
cent coins is higher.
Two different volumes of water at the same temperature
have the same amount of heat.
An analogy. Do two different piggy banks with different
amount of ten cent coins have the same amount of money?
More heat energy means higher temperature.
See the above analogies. Misconceptions and explanations
Light travels from our eyes to an object.
Light travels to our eyes and then to an object.
For both, light travels from a light source, to an object,
which then reflects the light into our eyes. The colors we
see when we look at objects are the colors that have been
reflected.
Larger magnets are stronger than smaller magnets.
The strength of a magnet depends on the degree in which
it has been magnetized and not the size. Imagine using the
stroke method to magnetize a large piece of iron by
stroking only one time and a small piece of iron by
stroking it 20 times. (assumption, both pieces of iron
differs only in size).
Misconceptions and explanations
Plastics (example) are insulators of heat.
Different matters conduct heat in various degrees and those
that do not allow heat to flow through well are called poor
conductors of heat, not insulators as the term implies that
there is no heat transfer at all.
All eggs will develop into young organisms.
Only fertilized eggs will develop into young organisms.
Always be careful if you see the word "all" in science as there
can be exceptions or differences under different conditions.
Flowers must have anthers and filaments to become a fruit.
The fruit is developed when ovules are fertilized in the
female part of the flower. Hence, the female parts of the
flower, the stigma, style and ovary must be present for such
to take place. The flowers can be pollinated by pollen grains
from other flowers.
Misconceptions and explanations
Plastics (example) are insulators of heat.
Different matters conduct heat in various degrees and those
that do not allow heat to flow through well are called poor
conductors of heat, not insulators as the term implies that
there is no heat transfer at all.
All eggs will develop into young organisms.
Only fertilized eggs will develop into young organisms.
Always be careful if you see the word "all" in science as there
can be exceptions or differences under different conditions.
Flowers must have anthers and filaments to become a fruit.
The fruit is developed when ovules are fertilized in the
female part of the flower. Hence, the female parts of the
flower, the stigma, style and ovary must be present for such
to take place. The flowers can be pollinated by pollen grains
from other flowers.
Misconceptions and explanations
All plant cells contains chloroplasts.
For most plants, only the leaves contain chloroplasts, which
gives the leaves their green color.
All cells contains a nucleus.
Red blood cells have no nucleus. Again, be careful of the
word 'all' when you encounter it in general statements.
Water does not gain heat when it is boiling as its temperature
is constant.
Heat is needed to enable the change of state from water to
steam.
Misconceptions and explanations
Breathing is respiration.
Breathing refers to the inflow and outflow of air into and
out of the body. Respiration refers to the process whereby
energy is released from food in the body, a process which
requires oxygen.
We breathe in oxygen and breathe out carbon dioxide.
We breathe in air and breathe out air also, with the only
difference being the amount of oxygen and carbon dioxide
these contain. The air we breathe in has higher
concentration of oxygen compared to the air we breathe
out. The air we breathe out has higher concentration of
carbon dioxide compared to the air we breathe in. It is also
a misconception if we think that the air we breathe out has
a higher concentration of carbon dioxide than oxygen.
Misconceptions and explanations
Plants respire at night and photosynthesizes in the day.
Respiration occurs all the time since plants need energy
constantly to carry out life processes. Photosynthesis occurs
when light is present (natural or man-made). However, most
of the time when such statements are made, the plants are
situated in natural surroundings or in areas where no other
light sources are mentioned so we can say that the plant
photosynthesises in the day.
Batteries store electricity.
Batteries contain chemicals that when connected in a circuit,
causes electrons to "flow" through the circuit. All non metals are insulators of electricity.
Graphite is a non metal and conducts electricity. (be careful
of the word "all")
Energy is used up.
Energy can only change from one form to another.
Misconceptions and explanations
Plants respire at night and photosynthesizes in the day.
Respiration occurs all the time since plants need energy
constantly to carry out life processes. Photosynthesis occurs
when light is present (natural or man-made). However, most
of the time when such statements are made, the plants are
situated in natural surroundings or in areas where no other
light sources are mentioned so we can say that the plant
photosynthesises in the day.
Batteries store electricity.
Batteries contain chemicals that when connected in a circuit,
causes electrons to "flow" through the circuit. All non metals are insulators of electricity.
Graphite is a non metal and conducts electricity. (be careful
of the word "all")
Energy is used up.
Energy can only change from one form to another.
Misconceptions and explanations
Friction exists only in moving objects.
Stationary objects have friction. Give a demonstration by
putting an object like a box on an inclined plane.
Earthworms, flies and snails etc are decomposers.
These organisms help in the process of decomposition but
they are not decomposers as they do not change the dead
matter into simple substances.
Other concerns:
Pupils forget the sequence in the life cycle of a plantpollination, fertilization, seed dispersal, germination etc.