Misconceptions in Biology - Eva Varga

September 4, 2015

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.


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?


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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