Exploring Melanin: A Journey into Genetics and Evolution in 9th-Grade Biology
In Holly Briggs' 9th-grade biology class, students have embarked on a fascinating exploration of melanin, a unit that explores the genetics behind evolution, seeking to answer the question: why do we observe varying melanin levels across the globe?
The unit commenced with a captivating case study featuring a family from Brazil. The family, comprising six children—three with Albinism and three without—paved the way for an in-depth examination of the genetic underpinnings of melanin production. Curious about the origins of Albinism in their lineage, the family sought answers from their dermatologist.
As students began to discover the intricacies of melanin's function—its role in protecting individuals from the sun while potentially hindering vitamin D production—they confronted the delicate balance between sun protection and vitamin synthesis. The study extended to the challenges faced by individuals with Albinism, from the necessity of sunscreen use to heightened susceptibility to melanoma. Two girls in the family, both with Albinism, illustrated the impact on eyesight, compelling them to sit closer to the board in school.
Students, inspired by the family's questions about Albinism, began to explore the topic further. They posed questions on sticky notes around the room, setting the stage for a deeper investigation into the genetic aspects of this phenomenon.
Pedigree analysis took center stage as students probed whether Albinism is a dominant or recessive trait. The focus shifted towards unraveling how individual genes shape physical appearances. The inquiry led to the examination of various mutations, ultimately decoding the chain of amino acids. The students then compared these amino acid sequences with corresponding phenotypes, paving the way for a comprehensive understanding of how DNA codes for proteins.
The culmination of the unit involves the identification of specific mutations, amino acids, and protein strands associated with Albinism in individuals. Through these explorations, students enhance their comprehension of genetics and evolution and gain insights into the intricate mechanisms governing physical appearances at a molecular level.
Briggs' biology class serves as a microcosm of scientific inquiry, where students actively unravel the mysteries of melanin, fostering a profound appreciation for the complex interplay between genetics, evolution, and human diversity.