Asking Questions in Biology

Background Content

Skin

Skin is the largest organ in the human body. The three main layers are epidermis, dermis, and hypodermis (see Figure 1). The primary function of skin is protection from bacteria, germs, sun, rain, and other elements. The epidermis also makes new cells to replace ones that are shed and provides skin color. The dermis, the layer below the epidermis, has collagen and elastin which make it strong and flexible. The dermis contains, hair follicles, sweat and oil glands, nerves, and blood vessels. The hypodermis is the bottom layer. It is fatty, provides cushion, connects to muscles and bones, regulates body temperature, and contains larger blood vessels and nerves.[1]

Figure 1: Skin cross-section; Courtesy of National Institute of General Medical Science (NIGMS)

The epidermis protects the dermis including the nerves, the sweat glands, and the ridge pattern. If the dermis is damaged, either through an injury or disease, a person could scar or permanently damage the ridge pattern.[2]

Have you ever stayed in the bathtub or a pool too long? What happens to your fingers and toes? They become wrinkly or prune. Do you know why?  It is because the skin on our hands and feet absorb the moisture. The rest of your body does not. Do you know why? What might repel water? Oil. The skin on the rest of our body has sebaceous oil glands. Why would we not want our hands and feet to be oily? Would oily skin help with our grasp? Oil would hinder our grip because it is slippery and causes less friction.

Taxonomy

Taxonomy is the study and classification of living and extinct species. Carl Linnaeus was a Swedish naturalist, known as the Father of Taxonomy. He first described the binomial nomenclature system in his 1735 work Systema Naturae which classified plants and animals into kingdom, class, order, genus and species.  Over time, the system expanded. Today it includes the categories: kingdom, phylum, class, order, family, genus, and species.[3] Figure 2 shows how humans, primates, and koalas are classified, which will be relevant in the fingerprint section below.

Figure 2: Taxonomic Classification Chart

Species with Fingerprints

The uniqueness of fingerprints was recognized for thousands of years, yet the discovery and understanding of fingerprints is the source of much debate. Why do humans have fingerprints? How do they form? Why do primates, humans, and koalas have fingerprints, whereas other animals do not? I believe my students will be interested in fingerprints and curious to learn more about them. Fingerprints are an evolutionary adaptation with which scientists are grappling to better understand. It is interesting that humans, primates, and koalas have fingerprints, but not other mammals that climb trees and have dexterity such as raccoons. Human fingerprints and an adult koala’s fingerprints are so similar that an electron microscope cannot distinguish between the two.[4] However, koalas only have ridges on their fingertips and on parts of their palms, while humans have ridges on the entire palm and fingers. Some scientists may argue that the fingerprint characteristic may have evolved before the mammalian split into placental and marsupial occurred. The mammalian split into placental and marsupial groups occurred early in the Cretaceous period about 130 million years ago.[5] In which case many more animals that climbed trees in the forest would have had fingerprints. Did the fingerprint trait disappear from many mammals and marsupials as did our tails? It seems unlikely. Why would the trait disappear if it helps arboreal mammals to survive? Another viewpoint is that koalas and humans both have fingerprints because of convergence, meaning that two lineages developed the traits independently through natural selection and not through a common ancestor.[6] Henneberg et al makes the claim that the adaptations evolved in arboreal environments to help grasp branches.[7] Fingerprints seem to be an adaptation for climbing as a result of environmental selection pressure.[8] Thus, fingerprints on humans and koalas would be an example of independent trait evolution.

Formation of Fingerprints

Special skin, or friction skin, forms on the hands and feet of primates. It is thicker than other skin and is adapted for climbing and grasping. It also contains many more sweat pores. Friction skin forms in the fourth week of pregnancy and generally does not change throughout a person’s lifetime, unless there is injury or disease. There is not one commonly accepted way that fingerprints form. The authors Kücken and Newell have observed fingerprints to determine how they form. In their 2005 article, they describe how they have used computer modeling and the outcome supports their previously-made observations. The ridge patterns and volar pads are closely connected.[9] The primary ridges form around the thirteenth gestational week. Sweat glands form in week sixteen and primary ridge formation terminates by week seventeen. Then smaller secondary ridges form. Volar pads are present during weeks nine through fifteen of gestation. According to Kücken and Newell, the epidermis is layered on top of a more fibrous amorphous dermis. The epidermis meets the dermis at the basal layer, and here cells form columns with an axis that is perpendicular to the skin surface. The basal layer then forms waves or undulations and form folds. The folds become the primary ridges. The patterning waves determine the fingerprint pattern type. Glover et al, shows that the unique fingerprint patterns are produced by a Turing reaction that is named after Alan Turing who showed with mathematical models how high-level patterns such as zebra stripes and leopard spots emerge due to particle diffusion and chemical reactions.[10]

Hypotheses

Since scientists strive to understand dermatoglyphics, they ask questions and propose hypotheses to determine the best explanation with the facts that they have at the current time. Henneberg et al, proposes two hypotheses to explain the dermatoglyphic similarities across species. “(1) dermatoglyphic similarities, due to high heritability of dermatoglyphic patterns, are an expression of genetic similarities, (2) dermatoglyphic similarities due to dermatoglyphic pattern configuration being dependent on the morphology of underlying structures, are an expression of functional, biomechanical similarities.”[11] Henneberg et al, then explains that the first hypothesis (1) can be proven false by showing that the similarities in fingerprint patterns are from distinctly separate taxa and the second hypothesis (2) can be corroborated by showing similar dermatoglyphic patterns in species that have diverse taxonomies.[12] This example demonstrates how scientists ask questions to work through the vast unknown, or area of ignorance, to explain the world around them.

There are various hypotheses to explain the purpose of fingerprints. Hoffman et al, makes the claim that enhanced sense of touch, known as the Fruit Texture hypothesis, suggests that fingerprints evolved to sense texture and determine the edibility of fruit.[13] When the ridges of a fingerprint rub over a surface, amplified vibrations occur. Our skin contains mechanoreceptors for fine textures and coarse textures.[14] The ridges enhance tactile sensitivity which scientists theorize helps animals determine the ripeness of fruit. Knowledge of how vibrations aid tactile sensations has potential to help improve prosthetic hand development in the future. The second hypotheses proposes that fingerprints improve grip by creating friction. Recently, Yum et al, describes how the fingerprint ridges control moisture thus enhancing grip in wet and dry situations. When the hands are wet, the ridges move the water away as ridges in a landscape funnel the water to the valleys. When the hands are dry, the abundance of sweat glands produce sweat to create moisture. Sometimes when our hands are too dry to pick up a piece of paper, people lick their fingertips to add moisture and improve their grip. Interestingly, new world monkeys, which are those found in Mexico, Central and South America have “tailprints” on their prehensile tails, which are used to grip branches.[15] Tailprints seem to provide compelling evidence that fingerprints form to help with grip. The various hypotheses that scientists have developed to explain aspects of fingerprints provides a glimpse of how scientists ask questions to come to some understanding and cut through a vast area of ignorance.

Fingerprint Types

The three most common patterns of fingerprints are arches, whorls, and loops (See Figure 3).

Figure 3: Image hand drawn by Valerie Schwarz

Arches are in the shape of arches similar to the image I conjure up in my head of an engineered structure such as a Roman aqueduct, a bridge, or a doorway. The tented arch comes to more of a point. Arches make up only 5% of the populations’s fingerprints. Loops go to one side of the digits. There are ulnar and radial loops. Ulnar loops are the most common and they curve toward the pinky or the side with the ulna bone. The radial loops curve backwards toward the thumb and the radial bone. Loops are the most popular type and comprise of 60-65% of fingerprints. There are left and right loops which indicate the side the ridges enter and leave. Whorls have concentric pattern of ridges in the center and comprise 35% of fingerprints. Double loops are a type of whorl in which two separate loops intertwine forming an S or W pattern. Pocket loops make complete circles, and the left/right direction tell the direction the loops enter and exit. A mixed figure combines two or more of the fingerprint patterns forming a rare and complex pattern. Triradii form a Y-shaped pattern with ridges intersecting from three different angles.[16]

Fingerprints as Identification

Since fingerprints are unique, they are used for identification, which may be to solve a crime or to identify a body. The use of fingerprints as unique identifiers dates back to Babylon and ancient China. According to a timeline in The Forensic Laboratory Handbook, a novel from China in 1200 used fingerprints in a criminal investigation. Knowledge of the ridges, pattern class, and use in fraud prevention developed from the 1600-1800. In 1890, Argentina developed the first fingerprint identification system to aid police investigations and in 1892, Argentina solved its first criminal case with the use of fingerprints.[17] The Federal Bureau of Investigation (FBI) in Washington, D.C. established the FBI Identification Division in 1924 because the police throughout the nation saw a need for a central location of fingerprint cards and arrest records.[18] Today, every country in the world stores fingerprint records, and some fingerprints have been digitalized.

More recently fingerprints are used for cybersecurity. Fingerprints are used for account protection and fraud detection. An example of account protection is that Apple computers use Touch ID to protect your device and privacy. Once Touch ID is set up, a sensor can easily read a fingerprint and allow or deny access.

Collecting and Analyzing Fingerprints

Our fingers pick up oils and dirt when our hands touch our face, hair, or objects. Then when our fingers touch objects we leave fingerprints behind. Some fingerprints are visible such as ones left on a computer screen, a mirror, or a cell phone. Others are hidden, or latent. Police and detectives look for prints visible and latent as a tool to solve crimes. Fingerprints from a crime scene must be handled carefully by an examiner. An important step in crime scene investigation is to gather the prints of all persons who regularly enter the space where the latent fingerprint was discovered. Detectives will gather inked prints from the people called elimination prints. Sometimes only fragments of the print exist, which makes analysis more difficult.

A variety of powders and chemicals are used to “develop” latent prints. Visible prints should be photographed. Prints that are found in dust or are greasy or bloody should not be brushed with powder as this will destroy them. Fingerprints that are wet must first be dried. Forensic scientists lightly brush powder over a “latent-bearing surface” and the powder sticks to the grease or moisture in the ridges, making the print visible. The color of the powder should contrast the color of the surface to make the fingerprints more prominent. Gray or black powder are preferred. Gray works well on mirrors and polished metal surfaces, while black works well on light -colored surfaces. Once the prints appear, the brush strokes should follow the direction of the ridges. Beginners tend to use too much or too little powder. Once the prints are dusted, they should be photographed before they are lifted using rubber and transparent tape. Black powder should be lifted on white tape and gray powder on black tape to enhance the contrast. The tape has a film over it that is removed before taking the print, and the print collector must be careful to avoid getting their own fingerprints on the tape. The print is then labeled including the operator (collector), date, and object from which it was collected.[19]

As a part of this curriculum unit, students will not only learn how to ink their own fingerprints, but also how to find and lift fingerprints around the classroom. The students will explore how their fingerprints are visible on Scotch^TM tape and on computer and cell phone screens. They will also explore how to use powders, brushes, and tape to lift fingerprints. As a part of learning to think like a scientist, the students will collect and analyze data some of which will include fingerprints.

Data Cycle

According to Boston University, “Data science is emerging as one of the most sought-after career paths of the 21st century.”[20] So it is no surprise that in 2025, there was a big push in Virginia to include the Data Cycle into lessons across all content areas. The Data Cycle as described by the Virginia Department of Education (VDOE) has four steps. They are: 1) formulate questions 2) collect or acquire data 3) organize and represent data and 4) analyze data and communicate results. In fourth grade, we review bar graphs from third grade, but the focus is line graphs. Students use the data cycle and create line graphs. An important understanding is that line graphs represent data over time. The data cycle is an important component of what scientists do as they work from discovery to knowledge.

Figure 4: The Data Cycle - Courtesy of: Focus on Mathematics Implementing the Data Cycle © 2025 by the Commonwealth of Virginia, Virginia Department of Education. All rights reserved. Reproduced by permission.

Questioning

In addition to scientists and inventors, venture capitalists ask questions that often lead to innovation. Netflix is a company that came to fruition because of a question. Warren Berger, author of Beautiful Questions in the Classroom, explains how Netflix was created when the founder asked why he should have to pay the late fees at Blockbuster? He wondered why no one had come up with a better way. More questions flooded his mind. What if the video rental business was more like a health club? Just like that, Netflix was born! The business continued to evolve in response to more questions. Why are we only renting films and shows? What if we made them too?[21] I want my students to learn how to formulate their own questions and use them for a purpose. Questioning will allow students to explore science, history, math, or any subject matter. It will teach them to be creative and innovative. I want to spark curiosity, engagement, and passion within my students and show them that asking questions is beneficial and not something to fear!

Questioning is a skill that separates humans from other primates. From an early age young children ask questions to gain new information and make sense of the world around them. When children learn to talk, they ask questions to learn the names or labels for objects. Paul Harris, a child psychologist from Harvard, reports that a child could ask about 40,000 questions between ages 2-5.[22]  As young children’s vocabulary develops between ages 2-5, the types of questions they ask also shifts from “Who?” “What?” then adding in “Where?” and “How?” and “Why?” as they try to understand how things work. As children ask questions their brains are making connections – about a quadrillion!! Research has shown that asking questions triggers reward processing, so it feels good and creates joy.

Studies show that as children enter preschool the number of questions they ask declines. This has been shown in various cultures throughout the world. Through research, a British psychologist, Susan Engel, found that children asked up to 26 questions per hour at home however, the number of questions asked for the same children dropped to two per hour at school.[23] Berger emphasizes that questioning stops in school. The article “The Creativity Crisis” published in Newsweek reports that, “Preschool children, on average, ask their parents about 100 questions a day. By middle school, they’ve pretty much stopped asking.” Figure 5 shows the decline in questioning that occurs with children.

Figure 5: The decline in questioning with age based on data from The Right Question Institute

There are several scientific reasons to support the decline in questioning. In young children the brain is rapidly forming synapses and connections, but around age five, “synaptic pruning” curtails the amount of questioning. Synaptic pruning is a natural process where our experiences strengthen the most relevant circuits and the weakest circuits fade.[24] As young children develop mental models and categories to understand the world, they do not ask to identify as many things around them. However, these neural changes alone do not fully explain the sharp decline in questioning, particularly in schools.

Berger lays out five enemies of classroom questioning: fear, apathy, ignorance, time, and culture. As a classroom teacher with almost 30 years of experience, I have seen all these questioning enemies play out in the classroom. Students are fearful of being wrong, fearful of showing their vulnerability that they do not understand a topic, and fearful of the perception of their peers. They may be afraid to look “nerdy” or show that they care about learning. They may be fearful that their question will be perceived as “wrong.” I have seen apathy play out when a student acts as if they do not care about learning because the reality is they struggle in their learning journey. It is easier to not care than to show one’s vulnerability. Some students do not care about learning, and some students bring trauma and other circumstances beyond their control, perhaps hunger or home situations that preoccupy their mind that limit the bandwidth for learning. Conformity and compliance are often required of students which can result in an unintended consequence of apathy. I have seen ignorance when a student may not have background knowledge, or may not understand the lesson, and they do not know what to ask. There often is a fear of looking ignorant. Berger states that while some questioning may be an innate skill, other questioning must be learned and practiced. If the innate questioning is not used for many years, “the question-asking muscle” (as Rothstein calls it) atrophies it must be strengthened.[25] The first three enemies to questioning, fear, apathy, and ignorance, seem to relate more to the students and the way they feel. The next two, time and culture, seem to relate to the teacher. Time is scarce with the vast number of standards that must be covered, and high-stakes testing has increased the pressure on students and teachers. In my quest to get through the required material, I often find myself limiting the number of questions I have the capacity to answer. Sarah Westbrook from the Right Question Institute (RQI) says, “We try to show that questioning can be a shortcut to deeper learning, rather than a detour.” She also explains that students’ questions reveal gaps in student understanding and thus enabling the teacher to fill in the gaps.[26] Berger considers the culture of the classroom as an enemy. The culture of a room where students are afraid to ask questions and afraid to be wrong certainly would be inimical. Berger makes the case that schools were designed during the Industrial Age and focused on compliance and memorization. While these skills may have been desirable during the Industrial Age, the 21^st-century is more suited for innovation and independence.[27] Knowing the enemies of questioning is vital as I design a curriculum unit to promote an environment where students will ask questions and formulate their own questions to drive their learning.

Create a Questioning Culture

According to Warren Berger, “Questioning is one of the most important and underrated skills a person can possess. It enables us to learn, understand, explore, adapt, and communicate.”[28] As the teacher, it is up to me to foster a culture where students are encouraged and taught to formulate their own questions. The students must first feel comfortable, valued, and willing to take risks.

This is clearly to the detriment of the students. After reading many books about questioning and the importance of having students formulate their own questions, I am going to figure out how to change my current practice, so that students are driving the questions. I want to become proficient with the questioning strategies and consummate at directing the focus through questioning techniques.

The Right Question Institute developed the Question Formulation Technique (QFT), which is described in more detail in the book, Make Just One Change Teach Students to Ask Their Own Questions. The authors of the book are also the founders of The Right Question Institute. The six core components of the QFT are:

• A Question Focus is typically created by the teacher, as I did with oceans (see below)
• Students produce questions
• Students work to identify and manipulate closed- and open-ended questions
• Students select priority questions
• A teacher and students determine next steps– what they will do with the priority questions
• Students will complete a reflection activity[29]

This past spring, I tested out a strategy that Berger suggested in preparation for the development of this unit. I had my students write as many questions as they could in a short period of time about a topic. Our topic was oceans, and the students were so engaged. After the students wrote their questions I took them and developed a short slide presentation based on them. One student, who loves bunnies, asked, “Why aren’t there bunnies in the ocean?” For fun I looked it up, and discovered that there are rabbit fish, whose mouths resemble a rabbit’s mouth and sea bunnies, which are mollusks without shells that live near Japan. I shared my discoveries with the class and showed them how questioning is a great way to learn more about topics about which they are passionate.

As I use the QFT protocol with this unit, I will teach the students to categorize questions as open and closed. Warren Berger describes questions as closed and open. Closed questions are questions that have a definitive answer. They may be “yes” or “no” questions or factual questions such as “How many ounces in one pound?” Open questions do not have a definitive answer. They tend to start with how, why, or what if. The next step is for the students to prioritize the questions, then we will decide the culminating project together. I will include a suggestion in the activities section.