Misconceptions in Biology

In a series of posts this week, I will be sharing 5 Misconceptions in Science and providing lessons and activities to help dispel these conceptual misunderstandings. Today’s post focuses on common misconceptions in biology.

misconceptionsbiologyMisconceptions in Biology

Misconceptions abound in all science disciplines, even in biology. Some of the misconceptions in biology that I have encountered include:

Coral reefs exist throughout the Gulf and North Atlantic waters.

Dinosaurs and cavemen lived at the same time.

Acquired characteristics can be inherited.

Houseflies live for only 24 hours.

Winter weather can be predicted by studying the thickness of the fur of some animals.

Humans are responsible for the extinction of the dinosaurs.

Why I am not able to dispel all of these in a single post, I’ve selected a couple that I think will work well in a middle school setting.

How to Dispel Misconceptions

As I stated previously, students should be encouraged to ask questions given ample opportunity to engage in hands-on experiments or demonstrations designed to test hypotheses.

In my post, Misconceptions in Astronomy, we explored using demonstrations to dispel the myth that the seasons are caused by the Earth’s tilt. Today will will explore how we can use hands-on inquiry activities and our own observations to dispel a couple of myths in biology.

MISCONCEPTION #5

Houseflies live for only 24 hours

The common housefly (Musca domestica) tends to live for about two to three weeks once it reaches the adult stage. The fly does move through all four of its life stages fairly quickly, 6 to 42 days for an egg to transform from larva to pupa to adult.

Eggs take a few hours to hatch into larvae, which in turn take a couple days or weeks to develop. Once the larva becomes a pupa with a protective case around it, it takes 2 to 10 days to emerge from its shell as an adult. Even after adulthood, it takes a few days for it to be able to reproduce.

They mayfly, which belongs to a different order of insects, also goes through multiple stages of development that lasts about a year. Mayflies lay their eggs in a body of water, where they typically gather on the bottom. They hatch into nymphs, which then undergo a number of molts before they make their way to the top of the water’s surface as a “pre-adult” with wings.

They eventually molt once more before final adulthood. Adult mayflies are not very long-lived as the digestive system stops working with the final molt, and the flies tend to die within a couple of days.

Try It :: Consider rearing housefies or flightless fruit flies in a terrarium to observe the complete life-cycle. How long do they live on average? Does their life-span differ by species?

BONUS MISCONCEPTION

Worms are found in apples

The ‘worm’ frequently featured in cartoons is actually the larva of the codling moth, Cydia pomonella. Female moths lay eggs on small developing apples or leaves. The larva tunnels through the skin and feeds on the seeds. Worms do not have legs, insects do. It would be very difficult for an earthworm to climb a tree or fly.

Try It :: Consider gathering a few apples from an orchard – a few picked from the tree and a few that have fallen on the ground. Place them in a small terrarium and observe what critters emerge from these “nurseries” as the apple decays. Use a hand lens or microscope to closely observe the anatomy of the larvae.

5 Misconceptions in Science & How to Dispel Them @EvaVarga.net

Don’t miss the posts I shared earlier this week:

Misconceptions in Science & How to Dispel Them (series introduction)

Misconceptions in Geology & Meteorology

Misconceptions in Chemistry & Physics

Misconceptions in Astronomy

This concludes my 5 day series featuring common misconceptions in science. If you have enjoyed the series, I encourage you to check out my Science Milestones series that focuses upon the discoveries and advancements of scientists through history.

This series is one of many hopscotch link-ups. Hop over and see what others are sharing.

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Misconceptions in Chemistry and Physics

In a series of posts this week, I will be sharing 5 Misconceptions in Science and providing lessons and activities to help dispel these conceptual misunderstandings. Today’s post focuses on common misconceptions in chemistry and physics.

Misconceptions in Chemistry @EvaVarga.net

Identifying & Dispelling Misconceptions

The first step in dispelling misconceptions is to identify them and to recognize their sources. To identify misconceptions, homeschool parents and teachers can:

  • use open-ended questions to assess what students know about the topic of a lesson.
  • listen and observe students’ answers
  • use direct questioning to discover the students’ reasoning process

Simply correcting a mistaken impression through discussion,  however, may not work. Instead, provide an opportunity for students to test out their theories. This is not only more convincing but develops their scientific reasoning skills.

  • First, help students to verbalize their understanding and thereby formulate a theory.
  • Secondly, guide them to set up an experiment to test their theory.

By using inquiry to test misconceptions, teachers can also foster respect for people, ideas, and scientific inquiry. Teachers can use misconceptions to provide unique opportunities to practice science process skills and interest students in scientific exploration.

Misconceptions in Chemistry & Physics

MISCONCEPTION #4

Comparing and contrasting physical and chemical changes, students may believe that because physical changes are often reversible, chemical changes are irreversible.

Many chemical reactions are NON-REVERSIBLE CHANGES .You cannot turn a baked cake back into its raw ingredients. Some chemical reactions can be reversed, and re-formed into the original substances. These are REVERSIBLE CHANGES.

A reversible change is a change that can be undone or reversed. Sometimes we also call these physical changes. A reversible change might change how a substance looks or feels (changing the physical appearance), and it is easy to turn it back again, but it doesn’t produce new substances.

For example, to demonstrate a reversible chemical change: Dip a heat-sensitive baby spoon and other objects that might change color into a beaker of hot water. Ask students to record their observations or results.

Students might notice that a baby spoon turned white when it was dipped in hot water and returned to its original color as it cooled. Ask students questions that will help them evaluate the results and draw new conclusions: “Did the baby spoon undergo a reversible chemical change?”

5 Misconceptions in Science & How to Dispel Them @EvaVarga.net

Misconceptions in Science & How to Dispel Them (series introduction)

Misconceptions in Astronomy 

Misconceptions in Geology & Meteorology

Misconceptions in Biology (coming Friday)

You might also be interested in my travel hopscotch,  Discovering Peru, where you’ll have the chance to win a travel guide of choice from DK Publishing.

My post is one of many hopscotch link-ups. Hop over and see what others are sharing.

Hopcotch2015

Misconceptions in Geology and Meteorology

In a series of posts this week, I will be sharing 5 Misconceptions in Science and providing lessons and activities to help dispel these conceptual misunderstandings. Today’s post focuses on common misconceptions in geology and meteorology. I’ve selected to highlight just a few.

Misconceptions in Geology @EvaVarga.net

Common Sources of Misconceptions

You may be asking yourself, how do misconceptions take root in the first place? Misconceptions are formed by a variety of contributing factors.

  • Everyday language can cause misconceptions. For example, students may have seen their parents buy or administer “plant food” and so believe that plants need food to grow.
  • Lack of evidence leads students to form mistaken conclusions. Because students cannot see germs or microscopic organic materials without a microscope, they may not grasp the concept.
  • Word of mouth, the media, and speculation all spread misconceptions.
  • Confusion over concepts can create wrong impressions.

Misconceptions in Geology & Meteorology

MISCONCEPTION #3

The greenhouse effect is caused when gasses in the atmosphere behave as a blanket and trap radiation which is then re-radiated to the earth.

First let me clarify that the greenhouse effect and global warming are NOT the same thing. The greenhouse effect is the name applied to the process which causes the surface of the Earth to be warmer than it would have been in the absence of an atmosphere. Global warming is the name given to an expected increase in the magnitude of the greenhouse effect, whereby the surface of the Earth will amost inevitably become hotter than it is now.

I will be discussing the greenhouse effect in this post – not global warming.

The fact that Earth has an average surface temperature comfortably between the boiling point and freezing point of water, and thus is suitable for our sort of life, cannot be explained by simply suggesting that our planet orbits at just the right distance from the sun to absorb just the right amount of solar radiation.

Parts of our atmosphere act as an insulating blanket of just the right thickness, trapping sufficient solar energy to keep the global average temperature in a pleasant range. This ‘blanket’ is a collection of atmospheric gases called ‘greenhouse gases’ based on the idea that the gases also ‘trap’ heat similarly to the glass walls of a greenhouse.

These gases, mainly water vapor ( ), carbon dioxide (), methane (), and nitrous oxide (), all act as effective global insulators. To understand why, it’s important to understand a few basic facts about solar radiation and the structure of atmospheric gases.

The following activities will help your students better understand the concepts described above.

What is a Greenhouse?

What Factors Impact a Greenhouse?

5 Misconceptions in Science & How to Dispel Them @EvaVarga.net

Misconceptions in Science & How to Dispel Them

Misconceptions in Astronomy

Misconceptions in Chemistry & Physics 

Misconceptions in Biology

You might also be interested in my travel hopscotch,  Discovering Peru, where you’ll have the chance to win a travel guide of choice from DK Publishing.

My post is one of many hopscotch link-ups. Hop over and see what others are sharing.

Hopcotch2015

5 Misconceptions in Science & How to Dispel Them

Misconceptions can be referred to as a preconceived notion or a conceptual misunderstanding. These are cases in which something a person knows and believes does not match what is known to be scientifically correct.

Concepts can be considered as ideas, objects, or events that help us understand the world around us. Misconceptions, on the other hand can be described as ideas that provide an incorrect understanding of such ideas, objects, or events that are constructed based on a person’s experience including such things as preconceived notions, non-scientific beliefs, naïve theories, mixed conceptions or conceptual misunderstandings.
5 Misconceptions in Science & How to Dispel Them @EvaVarga.netMisconceptions themselves can be related to such things as misunderstanding factual information or being given conflicting information from credible sources such as parents and teachers.

A lot of people who hold misconceptions do not even know that their ideas are false or incorrect. When they are told they are wrong, they often have a hard time giving up their misconceptions, especially if they have held this understanding for a long time.

Be very, very careful what you put into your head because you’ll never, ever get it out. ~ Thomas Wosely, British Cardinal

What is especially worrisome about misconceptions is that people continue to build knowledge on their current understandings. Possessing misconceptions can negatively impact an individual’s learning.

According to the American Institute of Physics, Children’s misconceptions about science are vast. As a science educator and homeschool mom, it is my goal to help change that.

Each day this week, I will be sharing 5 common misconceptions in science. In doing so, I will also provide hands-on activities and lessons that you can utilize with your students to correct these misconceptions.

MISCONCEPTION #1

The water in a sink (or toilet) rotates one way as it drains in the northern hemisphere and the other way in the southern hemisphere. Called the Coriolis Effect, it is caused by the rotation of the earth.

ScienceEquatorTo explore this misconception, I delight in taking you to La Mitad del Mundo – or the equatorial monument near Quito, Ecuador. It was here, while we were traveling in South America, that I experienced first hand how others use our misconceptions to mislead us – and often out of our money!

~ ~ ~

Later this week I will be sharing:

Misconceptions in Astronomy

Misconceptions in Geology & Meteorology

Misconceptions in Chemistry & Physics 

Misconceptions in Biology 

You might also be interested in my 5 day tour through Peru, Discovering Peru. Here you will have the chance to win a travel guide of choice from DK Publishing.

 

This series is one of many hopscotch link-ups. Hop over and see what others are sharing.

Hopcotch2015