Biology - Eva Varga

As a science educator, I have always relied on my own experience and the wealth of material that I have collected over the years to develop our homeschool science curriculum. I have also allowed the interests of my children to drive our studies, ensuring that we also cover a variety of topics.

Months ago, when we were in the midst of our Human Anatomy unit with our STEM Club, I realized that I needed to go more in-depth, specifically for my daughter. I hadn’t taught high school level science, however, so I was a little apprehensive. Would I be able to find labs that would be both challenging and adaptable for the homeschool setting?

As I began my research, I was delighted to discover a great resource for teaching middle school and high school biology, Amy Brown Science. As I browsed her website and the products available at her Teachers Pay Teachers store, I was immediately drawn to her Genetics Complete Bundle Unit and am delighted to share with you how we’ve begun to use it in our homeschool.

Genetics Unit Bundle

Though my son is a few years younger than my daughter, I generally teach them both simultaneously. I thereby began our study by reading aloud, Gregor Mendel: The Friar Who Grew Peas. While this is a picture book, I have found that everyone enjoys listening to quality literature and it was a great way to spark interest in the new unit. I then followed up with Amy’s Genetics Warm-ups to review the material that was covered in the book.

Note: The warm-ups are a separate item in Amy’s TpT store and are not part of the Genetics Complete Bundle. However, they are the perfect tool for review and reinforcement.

Together, we viewed the PowerPoint and took notes along the way. My daughter and I have now begun to progress slowly through the material in the bundle. There is really so very much – it will take us a while to complete everything. I am impressed with the quality of the material – the lessons are laid out very clearly and each warm-up includes a teacher’s answer key.

My favorite component are the labs: Simple DNA Extraction, Effect of Environment on Gene Expression, and The Hardy Weinberg Equation. While each is available individually, the fact that they are bundled not only saves me time but puts everything into context.

Amy does an excellent job of describing the lab procedures in a way that students can easily follow along. She also provides tips for the teacher in regards to set-up and preparation.

The genetics unit focuses almost entirely on Mendelian genetics and on genetics topics that arose after Mendel’s death. The materials do include some discussion of Darwin and natural selection.

The Genetics Complete Unit Plan Bundle contains at least 3 weeks of materials depending on how many lab activities you want to do. This unit has everything that a teacher needs to teach a unit on genetics to Biology or life science students in grades 8-12.

The bundle includes:

A 61 Slide PowerPoint
Teacher Notes
Student Notes
3 Labs
A Jeopardy-style game to review concepts
5 Quizzes
7 Genetics Practice Problem Worksheets
A Crossword Puzzle
A Unit Test

Wow! All that for a bundled price of just $25.99! This is a savings of 39% off the price if you were to purchase the items individually.

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.

Misconceptions 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.

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.

The Dean Creek Elk Viewing Area and the O.H. Hinsdale Interpretive Center are popular tourist stops along Hwy. 38 near Reedsport. Here, visitors are able to observe up-close views of Roosevelt Elk, with the herd sometimes reaching as many as 120 elk. This area of mountains, meadows, and marshes also are home to beaver, coyote, muskrat, mallards, Canada geese, and great blue heron.

Roosevelt Elk: A Nature Study @EvaVarga.net The Roosevelt Elk are native to the area and are considered Oregon’s largest land animal. Inhabiting forests and meadows from northern California to British Columbia, they are the largest of six sub-species of elk. They generally live between 10 to 15 years, but some may live more than 20 years.

In this short video by Chris Cru, you can observe the Roosevelt Elk peacefully grazing as well as a coyote running in the background.

The antlers of a Roosevelt elk can reach spreads of nearly 3 feet and are thicker than the antlers of the Rocky Mountain elk. Older, stronger bulls have larger antlers, with 6 or more points per side, while yearling bulls have single spikes.

A mature bull elk can weigh an imposing 700 to 1200 pounds, standing 5 feet tall at the shoulder. Cows weigh about 500 to 700 pounds, while a calf weighs just 23 to 45 pounds at birth.

Their brown-gray winter coat will turn to a glossy, reddish-bay color in the summer. A tawny rump patch is outlined in black and they boast a thicker mane. At birth, calves are spotted and more tawny in color. As mature elk age, their coats will lighten in color.

Roosevelt Elk: A Nature Study @EvaVarga.net — Using a range finder to calculate our distance apart

Nature predators include mountain lion and black bear which primarily feed on new calves and sick animals. When approached or threatened, both cows and bulls will use their sharp front hooves for protection. Cows will bark an alarm that sounds like a high-pitched neigh while calves will bleat when danger approaches.

In late summer, bulls shed their velvet by rubbing antlers against tree limbs and bushes until the new antlers are hardened and shiny. This helps the males win over the female when the mating season begins in autumn.

The elk bulls bugle during the fall season. This is a great time to see the males in action. The bull elk’s deep, resonating bugle can be heard across the meadow as the males call to attract a female, move in to spar with a competitor, and take control of the harem.

To signal their status and fitness, the bulls will wallow in mud and spray themselves with urine. They will also tangle plants in their antlers to appear more imposing and better emphasize their size and power.

Roosevelt Elk: A Nature Study @EvaVarga.net When the rut season is over, the females will force the males out of the heard once again. He will generally join up with a small group of other males though occasionally he’ll remain solitary. They then focus on grazing to gain nourishment fro the oncoming winter months.

The bulls drop their antlers in the later winter which become an important source of calcium for smaller forest mammals including coyotes, squirrels, and mice.

~ ~ ~

We’ve always enjoyed taking part in the monthly challenges at Handbook of Nature Study. This month our selected challenge was to Sketch Outdoors.

When my son was diagnosed with congenital nystagmus as an infant, I became increasingly interested in heredity or the passing of phenotypic traits from parents to their offspring. Both my brothers also have nystagmus and it was now clear that I carry the gene as does my daughter.

The Father of Genetics, Gregor Mendel @EvaVarga.net

This post contains affiliate links.

Nystagmus is inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes in each cell. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two copies of the X chromosome), one altered copy of the gene in each cell can cause the condition, although affected females may experience less severe symptoms than affected males.

Genetics is the study of genes, heredity, and genetic variation in living organisms.

Single gene inheritance is also referred to as Mendelian inheritance as it follows transmission patterns Gregor Mendel, a late 19th-century scientist and Augustinian friar, observed in his research on peas. As a result of his work, he is known as the Father of Genetics.

Mendel studied ‘trait inheritance’ or how different traits are passed on from parents to their children. He observed that organisms (pea plants) inherit traits by way of discrete “units of inheritance”. This term is a somewhat ambiguous definition of what is referred to today as a gene.

The four types of Mendelian inheritance patterns he described include:

Autosomal: the gene responsible for the phenotype is located on one of the 22 pairs of autosomes (non-sex determining chromosomes).

X-linked: the gene that encodes for the trait is located on the X chromosome.

Dominant: conditions that are manifest in heterozygotes (individuals with just one copy of the mutant allele).

Recessive: conditions are only manifest in individuals who have two copies of the mutant allele (are homozygous).

Biography

The Father of Genetics, Gregor Mendel @EvaVarga.net Johann Mendel was born July 20, 1822, in Heinzendorf bei Odrau, a small village in the Czech Republic (formerly the Austrian Empire). His parents were small farmers who made financial sacrifices to pay for his education.

He entered the University of Olomouc in 1840. He took courses in physics, mathematics and philosophy. He was advised by a professor to join the Abbey of St. Thomas in Brünn as a monk when he was 21 years of age to help offset the cost of his education.

The Abbey actually had a good reputation for its teaching of sciences, and its director, Abbot Franz Cyril Napp, was particularly interested in heredity of traits in plants and animals on farms. Upon joining the Abbey, he took the name Gregor.

My scientific studies have afforded me great satisfaction; and I am convinced that it will not be long before the whole world acknowledges the results of my work. ~ Gregor Mendel

After completing his studies, he returned to the monastery in 1854 and took a position as a physics teacher at a school at Brünn, where he taught for the next 16 years. The monastery had a 5 acre garden, and two former professors encouraged Mendel to pursue his interest in heredity by using the garden for experiments.

Mendel set himself the very ambitious task of discovering the laws of heredity. To achieve this, he embarked on a highly systematic, eight year study of edible peas, individually and carefully recording the traits shown by every plant in successive generations. His work involved growing and recording the traits in about 30,000 plants.

One of the keys to his success was breeding from closely related pea varieties which would differ in only a small number of traits. The seven traits of pea plants that Mendel chose to study: seed wrinkles; seed color; seed-coat color, which leads to flower color; pod shape; pod color; flower location; and plant height.

In 1866, he published his heredity work, though it was not immediately recognized for the wealth of information it contained.

Bring it Home

? Explore genetics in more depth with a Genetics Unit Bundle from Amy Brown.

? Use M&M’s to visually see the genetic probability that an offspring will carry a certain trait. Just don’t each them all before you finish!

? Explore the genetics of sickle cell disease through Punnett squares, pedigrees, and an optional chi-square analysis with this classroom activity from the Howard Hughes Medical Institute.

? Enjoy this 3-D animation, available in both basic and advanced detail, which depicts the molecular machinery responsible for quickly and accurately copying DNA.

? Here is a cute video of an interview with Gregor Mendel from Untamed Science.

? Download the free printables from Stephanie Harrington and enjoy the book Gregor Mendel: The Friar Who Grew Peas.

? Create a DNA model of your own using pipe cleaners and beads or if you prefer, Lego bricks.

? Erect a DNA Double Helix Table Sculpture Puzzle

? If you still have those M&Ms, consider this Easter egg and M&M genetics activity from All Things Beautiful!

Science Milestones

Visit my Science Milestones page to learn more about scientists whose discoveries and advancements have made a significant difference in our lives or who have advanced our understanding of the world around us.

The bloggers of the iHomeschool Network have teamed up to create fun and original unit studies on fascinating people who were born in July.

I was recently sitting on the pool deck one afternoon waiting for our kids to finish swim practice. As summer was still just a few weeks away, a few moms and I got to talking about activities to keep the kids engaged through the hot summer.

One mom suggested a subscription kit. “Yeah, but there are so many available today,” one mom replied. “How does one choose?”

I was delighted to share with them my experience with Junior Explorers. When choosing a subscription box – either as a gift or as a curriculum enrichment – my suggestion is to keep the interest and passion of the recipient in mind.

While my son is in the target age, a child passionate about animals would be the ideal recipient for Junior Explorers. I knew the perfect little zoologist – my friend, Liam, who was recently promoted to first grade! I was delighted to be able to assign him his first mission, Mission Amazon.

I received the Junior Explorers mission kit in exchange for an honest review. All opinions expressed are true and completely our own. Please see my disclosure policy for more information. This post contains affiliate links.

Like many children, Liam loves animals and while waiting for his big brother at swim team, he will often role-play what he has learned in school or in the books he has brought along with him.

Junior Explorers helps foster that love to inspire the next generation of environmental stewards. Junior Explorers is a subscription program for kids 6-11 that teaches them all about wildlife and nature through exciting adventures that are sent home each month. Every month kids receive a kit in the mail sending them to a new ecosystem to solve a mystery in nature.

Each monthly mission focuses on a new ecosystem with real facts about wildlife and the environmental threats today. This can be a hard conversation to have with kids, but Junior Explorers introduces the topics in an easy-to-understand and solution oriented way.

The monthly kit contains cool collectibles like figurines, animal trading cards, temporary tattoos, stickers, and more. Every kit also includes a secret code to access a wealth of activities, games, and additional learning materials.

Liam loved the animal trading cards with facts about the featured animals best. “Did you know there are frogs that sweat poison?!” he exclaimed. I didn’t get a chance to elicit more details, he hopped off in delightful imaginary play.

At the end of every mission, kids see a handful of not-for-profit projects doing front-line conservation in the ecosystem they just visited. Kids select their favorite real-world project and watch as their earned points are converted into a real dollar donation.

Junior Explorers is a certified B-Corporation and while this may not mean anything to Liam, us moms can smile knowing that the company has met rigorous standards and been designated as a company that is doing good for the world.

Shipping is only $2 per month to send your child on wild adventures with Junior Explorers subscription boxes! Join Now!

This post contains affiliate links.

Marine biologist and author Rachel Carson, whose writing on pesticides helped to launch the modern environmental movement, was born on 27th of May in 1907 in Springdale, Pennsylvania. Carson published her famous work Silent Spring in 1962 which documented the dangers of indiscriminate use of synthetic pesticides, especially on bird populations. Though its publication was met with strong opposition from the chemical industry, the scientific community largely supported her conclusions. Silent Spring also served as a rallying point for the young environment movement just gaining momentum at the time of its publication.

In nature nothing exists alone.

The book fueled public interest in environmental and public health issues and, within a few years, the Nixon Administration formed the Environmental Protection Agency. Much of the EPA’s early work focused on issues raised by Carson’s work such as a 1972 law regulating pesticides and a US ban on the agricultural use of DDT.

Biography

Rachel grew up in a tiny, wooden house with no electricity, heat or plumbing. As a young girl, she was fascinated with the outside world. She spent a great deal of time in the woods and beside streams learning the names of birds, insects, and flowers.

Rachel’s best friend was her mother, Maria Carson, with whom she enjoyed taking long walks with in their nearby woods. Maria had been a teacher before she married and she taught Rachel the names of plants, birds, insects, and animals they encountered. It didn’t take long before Rachel was able to identify dozens of wild things.

Those who contemplate the beauty of the earth find resources of strength that will endure as long as life lasts.

In Rachel’s second year of college, she took a biology course that sparked her interest in this area. She graduated from college with honors and decided to specialize in Marine Biology- the study of animal life in the ocean. In 1929, she won a full scholarship to John Hopkins University in Baltimore, Maryland to obtain her graduate degree in this field of study.

After graduating from Johns Hopkins in 1932 (MA in Zoology), she began a career in the federal service as a scientist and editor and rose to become Editor-in-Chief of all publications for the U. S. Fish and Wildlife Service.

In addition to the well known Silent Spring, she wrote several other articles designed to teach people about the wonder and beauty of the living world, including “Help Your Child to Wonder,” (1956) and “Our Ever-Changing Shore” (1957). Woven throughout her writing was the view that human beings were but one part of nature distinguished primarily by their power to alter it, in some cases irreversibly.

Man is a part of nature, and his war against nature is inevitably a war against himself.

Rachel Carson died in 1964 after a long battle against breast cancer. Her witness for the beauty and integrity of life continues to inspire new generations to protect the living world and all its creatures.

Bring It Home

With Rachel Carson as a guide, students can learn how environmental concerns affect their lives and community. High students should be encouraged to read Silent Spring. Middle school students may be more comfortable reading selected chapters; I recommend the first chapter “A Fable for Tomorrow,” which can be previewed online. [Tip: Do a search on the chapter title to find the full text, which is available from various sources.]

Read a biography:
- Rachel Carson and Her Book That Changed the World for ages 5 to 8
- Rachel Carson: Preserving a Sense of Wonder
- Who Was Rachel Carson?
- Girls Who Looked Under Rocks: The Lives of Six Pioneering Naturalists (for ages 10 and up)
- Headstrong: 52 Women Who Changed Science-and the World(recommended for teens and adults)
Watch the compelling documentary film American Experience: Rachel Carson’s Silent Spring
Have the students write a short story about how they think the world will change in the next ten years.
Ask students how they perceive our oceans being polluted today and let them come up with ways we can contribute to the efforts of protecting our sea life.
Have students research the toxic effects of DDT on the body, where it might be used today, and what alternatives can be used in its place.
Ask students to make a booklet on ways to live that can reduce an individual’s impact on the environment. Examples of subjects include saving water, gardening, cleaning and maintenance around the house, your car, renewable energy, air pollution, and the environmentally aware consumer.
Interview a person who has lived in the community for 30 years or longer. Suggested questions might include:
- How has our community’s environment changed over the time you have lived here?
- What was the environment of our community like when you first lived here?
- What changes made the greatest impact on the environment?
- Have the changes been for the better? Why do you feel this way?
- In retrospect, compare the benefits and detriments of the impact of people on the land.

What about us? Can we avoid the “silent spring” that Carson predicted? In the 53 years since Silent Spring first appeared, people have grown far more aware of our impact on the environment. But we still use many potentially deadly chemicals.”There remains, in this space-age universe,” wrote Rachel Carson, “the possibility that man’s way is not always best.” We would do well to remember her warning.