The human eye may be only about the size of a ping-pong ball, but it is an amazingly complex sensory organ that requires all of its components to function properly in order for a person to have optimal vision. Each part of the eye works together with the others to process light rays into electrical impulses, or messages that are transmitted to the brain. The brain interprets this information and allows us to be aware of our surroundings. Our eyes and brain are able to capture and interpret millions of images a day, shaping our view of the world.
In 1953, Francis Crick and James Watson discovered the structure of the DNA molecule, the double helix. Their discovery led to many developments in the fields of forensic science and biotechnology and in the understanding of heredity and genetic diseases. The two high school seniors featured in this SciFri Vfideo were able to apply DNA extraction for a more practical application: to find out what really is in the food that we eat. In this activity, students will review and discuss the definition, function and importance of DNA.
Some microbes produce different types of gases as a byproduct of their metabolic processes. The microbes in this Science Friday Video released an odorless and flammable gas called methane. The type of gas or gases released by a microbe depends on the species and their metabolic characteristics. In this activity, students will conduct an experiment to observe the metabolic process of yeast by using household ingredients. Students will vary conditions in the yeast’s surrounding environment and observe the amount of gas that the yeast releases
Nanotechnology is the study of what happens when things get very, very small â€“ only a few atoms in size. The word “nanometer” means one billionth of a meter, perhaps five or six atoms long. At the nanoscale, materials can have very different physical or chemical properties, even though they are the same. In particular, super thin films of material, only a few nanometers thick, can cause interference within light reflecting off them, resulting in beautiful displays of colors.
A crystal is a natural solid made up of a repeated pattern of molecules connected together. Crystals can form through the slow cooling of molten material (gemstones), or when a warm gas such as oxygen cools down (snowflakes), or when a liquid that contains dissolved minerals cools very slowly (salt). In this activity, students will observe various substances and determine whether these substances are crystals based on their physical properties. They will also learn one of the processes for crystal formation and how to create their own crystals by cooling a supersaturated solution.
Sound is all around us. Everything we hear in our day-to-day lives has a distinctive sound, from the jingling of keys to the tapping of footsteps in a hallway. Sound is created when objects vibrate. These vibrations cause the air around them to vibrate, sending sound waves in various directions. Some objects tend to vibrate at a specific rate. This is known as their resonant frequency. In this activity, students will explore the vibrating nature of sound and how it travels from molecule to molecule.
Complex fluids are special kinds of mixtures that have characteristics of more than one phase of matter. In this video, the combination of cornstarch and water resulted in a substance that exhibited the properties of a solid and a liquid depending on the amount of pressure or force applied to it. These types of fluids that don’t behave like what we think of as “normal” fluids are called non-Newtonian fluids. Many non-Newtonian fluids are made of polymers, long chains of repeating molecules that give the fluid unusual physical properties such as flexibility and strength.
In this lesson, students will be amateur mycologists–collecting and analyzing various mushrooms. Through observation and discussion, students will gain knowledge of the basic anatomy of mushrooms, their life cycle, and their method of reproduction through spores. Students will learn to create spore prints of mushrooms and label and preserve their spore prints, just like a mycologist. Students also will learn that by comparing spore prints, they can identify different mushroom species.
Many popular sports, including basketball, are based upon the use of a ball. Yet each type of ball is easily associated with a specific sport, because each ball is distinctly different. A ball’s performance is directly influenced by its characteristics or properties. For example, the oval shape of a football allows it to travel farther in the air than a ball that is round. In this activity, students will explore the properties of various balls from different sports, and discuss why the design of each ball is suited to its associated sport.
Bacteria are one-celled organisms that can only be seen under a microscope. There are thousands of kinds of bacteria, and they are found everywhere – in the air, in the depths of the ocean, in the human body and on human skin. Under favorable conditions, bacteria can multiply rapidly and form colonies (millions of bacterial cells grouped together) that can be observed with the naked eye. In this activity, students will formulate a hypothesis about which area of skin on their bodies may have the most or least amount or kinds of bacteria.