We’ve had a lot of fun making a lot of different circuits, now let’s step it up a notch and build a percussion instrument synthesizer. This circuit will build on what we’ve learned so far and use a lot of different parts to create a synthesizer that will generate a plucked string or drum sound. Are you ready to make some more noise? I am!
A comparators is a form of an Op AMP that can either be on or off. This may not sound useful, but you can do things with comparators that are very useful. To demonstrate this, let’s take a look at comparators, what they are, and how to use them. In this experiment we’ll get use a comparator to control two different LEDs, and when the comparator is off, one LED will glow and when the comparator is on the other LED will glow.
Oh, this one is about LED bargraphs, and you know I love LEDs. In this experiment we are going to build an LED bargraph and then use that bargraph to measure how much light is hitting the photoresistor. In essence, we are going to build an LED bargraph light meter!
Let’s have some more fun with the photoresistor and build a buzzer that has two modes. The first will be the buzzer triggering off of light and the second will be the buzzer triggering off of darkness. This circuit is exactly how a laser eye alarm works and we can try this by setting the circuit up to trigger when someone walks through a door! I’m not waiting, I’m doing this one now!
Did you like the bargraph experiment? Well, in this one we are going to build a bigger and better bargraph. In this experiment we’ll build a 8 segment LED bargraph that has a sensitivity adjustment. You know me and LEDs, so let’s get wiring!
Did you know that VCO stand for Voltage Controller Oscillator? Well, in this experiment we are going to build one using a 555 timer, a few capacitors, and a potentiometer. We’ll then send the signal from the VCO to the speaker and make some neat tones!
Timers are really neat, and we’ve already seen a few in action. Now, let’s build one that operate the buzzer and an LED and can run both for up to 100 seconds. We’ll be using a 555 timer, several capacitors, a potentiometer, and a few switches as well. Sound like fun to me!
We’ve created a lot of circuits together and now it’s time to start looking at a new part, the 4046 is a Phased-Locked Loop IC that contains both analog and digital circuitry inside. Well be using the 4046 to help generate the siren sound for this circuit. We’ll also be using the 555 timer and all the potentiometers in the kit. So let’s get started and build us a siren!
Want to see how computers add? Well, in this experiment we are going to use a exclusive OR gate to build a binary half adder to get an idea of how computers add numbers. This is a critical lesson in understanding binary and how binary numbers are added together, we’ll also expand on this experiment in the next video.
This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn!
Discover the world of clean, renewable energy that scientists are developing today! Explore how they are harnessing the energy of tides and waves, lean how cars can run on just sunlight and water, tour a hydroelectric power plant, visit the largest wind farms on the planet, and more! You’ll learn how streets are being designed to generate electricity, how teenagers are making jet fuel from pond scum in their garage, and how 70 million tons of salt can provide free, clean energy 24 hours a day forever! During class, you’ll learn how to bake solar cookies, magni-fry marshmallows and do the experiment with light Einstein won a Nobel prize for that is the basis of all photovoltaic energy today.
Materials:
If you enjoyed these experiments, then you’re in for a real treat, because there’s a lot MORE experiments in Lesson 4: Digital Logic!
Since the mid 1980’s, digital electronics have slowly become an ever increasing part of our lives. And now, you’d be hard pressed to find any device that doesn’t use digital electronics. Digital electronics are in the TV you watch, your computer, your phone, your car, the appliances in your kitchen, and so much more. So, to help understand how digital works, we’ll be exploring digital electronics in this series of videos.
We are going to cover a lot of ground in workbook 2 beginning with learning about the basics of digital electronics. This will include learning what a bit is, what a high and a low are, basic digital gates, among other topics.
Click here to view the next set of experiments in Electronics.
Your brain is divided into two sides, called hemispheres. Through experiments, scientists have determined that each side is responsible for different things. We’ll talk more about this in Unit 19, but for now, just know that the left side of the brain is mainly responsible for language, while the right side is in charge of spatial perception. Also, each side of the brain controls the action of the opposite side of the body.
Humans are not the only animals with different hemispheres controlling different actions. This experiment will explore if feeding in lizards is controlled mainly by one side of the body, and if lizards feed mainly to one side.
Here’s how to experiment with lizard brain lateralization:
1. Obtain a lizard in a terrarium – can you find a friend that already has one and borrow it?
2. Set up a video camera to record the lizard for several days.
3. Place live crickets in the terrarium for the lizard to eat. Watch the lizard eat a few to get an idea of what the strike looks like, but the since you are capturing the action on video, you don’t need to sit there all day.
4. Watch the video of each cricket capture. If possible watch in slow motion.
5. Cover the monitor on which you are watching the strikes with clear plastic wrap, and draw a line from the center of the lizard prior to the strike (right between the eyes) to the point of capture. Be careful that nothing you are doing will damage your monitor.
6. Do this for all the strikes. (Twenty would be a good number to get some reliable data, but realize that will make this experiment take some time, as lizards take a while to eat 20 crickets.)
7. Once you have all your lines drawn, count the number of times the lizard struck to the left, struck to the right, or went straight ahead. Record your results.
What’s Happening: Remember that each side of the brain controls the opposite side of the body. You can determine with side of the lizard’s brain is more responsible for predation (eating) based on which side it strikes on more often. This will vary from lizard to lizard.
Mirror, Mirror, on The Wall… Did you know that a betta fish has a special relationship with a mirror? When you look in a mirror, you recognize that what you see is your reflection. Not all animals realize this. Many animals think the animal they see is another member of their species, and react with either fear or a show or bravado to defend to defend their territory.
Let’s examine the reaction of the standard betta. You’ll need a male betta in a bowl and a mirror… and a little bit of time.
1. Obtain a male betta, and place it alone in a bowl.
2. Place a mirror in the bowl.
3. When the betta sees his reflection, record his response.
What’s happening: Most male bettas will respond by showing all of their fins, a behavior known as flaring, designed to make the fish look large, and protect their territory. When mirrors have been left in bowls, males have become so obsessed with flaring they have even forgotten to eat and died, so take the mirror out as soon as the experiment is over!
In the animal kingdom, only primates have been shown to generally understand that they are looking at themselves in the mirror. Amongst humans, babies under 10 months of age generally don’t understand this concept. If your betta did not react by flaring, see if you can think of why. Is the fish used to living with others and not very territorial? This is the trouble with only testing one animal. There are usually other factors involved.
Lizards and snakes make up the largest order of the reptiles. Although we often think of them differently, snakes are basically legless lizards, from a biological perspective. Reptiles in this group are characterized by having scales or shields on their body and by having a lower jawbone that can be moved independently from the braincase. This allows snakes and lizards to open their mouths very wide, a trait that is especially noticeable when snakes, which also have a very flexible jaw, are eating relatively large food, as you can see below:
Besides the obvious lack of legs, snakes are distinguished from lizard by the lack of external ears. Snakes are all carnivorous, meaning they eat meat of other animals. Snakes frequently eat rodents, insects, eggs, and even other snakes. Almost all snakes lay eggs, and they generally abandon the eggs shortly after laying them.
The somewhat unusual body structure of snakes leads to some unusual characteristics. As was mentioned above, snakes have very flexible jaws. This helps make up for the fact that they cannot use limbs to grasp prey, like most animals do. Also, because their bodies are so long and narrow, if a snake has two of a certain organ, such as the kidney, they are found one in front of the other as opposed to side by side.
Only a small minority of snakes have venom. Of those that do, venom is usually used to immobilize and begin to digest prey, rather than as a means of self-defense. Nevertheless, snake bites can be both painful and dangerous, so it is always best to steer clear of snakes (as well as most other animals) in the wild. Snakes without venom usually kill prey by constricting, or wrapping their bodies around the prey and squeezing tightly.
About 6,000 species of animals belong to the class amphibia, commonly called the amphibians. A class is a group of living things in the same phylum or sub-phylum (in this case, vertebrata) that share certain characteristics. One of the most important characteristics they share is that they begin life in the water, but then spend most of their lives on land.
Although amphibians inhabit many environments, from tropical to arctic climates, they cannot live in saltwater, eliminating the oceans as a place to find these animals. Some amphibians do live in brackish water, which is slightly salty, but these animals generally live in or near freshwater. Amphibians are ectothermic and carnivorous, generally feeding on bugs and other arthropods.
The life cycle of amphibians is one of the most interesting of the vertebrates. Adult animals lay a shell-less egg, usually in a pond or some other freshwater location. A larva then hatches. The legless larva lives in the water, breathing through gills, as fish do. Slowly, over time, the larva undergoes a metamorphosis, or change in body structure. During this change, the larva takes on the adult form, losing its gills, growing four legs, and eventually becoming completely terrestrial, meaning that it lives only on land.
The lifecycle of the frog, in which the larva is called a tadpole, is typical of amphibians.
As part of becoming terrestrial, amphibians must undergo several changes. Their gills are replaced with another respiratory organ, like lungs, allowing them to breathe on land. Their skin also undergoes a change to keep them from losing water and becoming dehydrated. They develop eyelids to more effectively see in a terrestrial environment. Finally, an eardrum develops separating the exterior from the middle ear.
About 500 amphibian species are salamanders. These animals are generally characterized by tails, short legs, and moist skin. The moist skin of the salamander requires them to live in or near water more than many other amphibians. In fact, some salamanders live their whole lives in water. Others live outside water in the adult stage, but stay in swamps, where the ground is moist, and will not dehydrate their skin.
Salamanders are unique in both their respiration and feeding. Some salamanders have lungs and breathe in a way similar to mammals. Others keep their gills into adulthood, and remain in the water, breathing through their gills. Still others have neither gills nor lungs, and breathe through valerian respiration in which air is passed through the skin. In terms of hunting, a muscle called the hyoid muscle shoots out, along with the tongue. The tongue of the salamander is covered in mucus, and prey is captured in this sticky mucus. Salamanders are also the only vertebrate that can regenerate lost limbs.
Frogs and toads are members of the same order, which is a group of similar living things in the same class. People sometimes distinguish frogs and toads based on the fact that toads usually live in drier environments, and have leathery skin to help them in this environment.
However, there is really very little difference between animals referred to as “frogs” and “toads” in this reading, other than the fact that toads do not have any teeth and must swallow their food whole. To make things simpler in this reading, we will just call this group of animals “frogs.”
Frogs can be characterized by long legs and the absence of a tail. They spend their adulthood out of the water, breathing through lungs. Frogs enter the water in the adult stage only to reproduce. For this reason, the males of many species of frogs have mating calls to draw females into the water to reproduce.
Did you know that in order to catch a frog, all you need is a lure and a fishing pole?
Once frogs lay eggs, they are generally fairly easy to spot in and around the swamps and marshes in which they live. Each frog egg starts out as a tiny dark spot surrounded by a thick layer of clear jelly-like stuff. The jelly acts kind of like a shell that protects the egg. Most frogs’ eggs form clumps. This activity will work around April, when frogs lay their eggs.
1. Visit a local pond or swamp and seek out some frogs. Listen for frog sounds and see if you can identify the type of frog.
2. Once you’ve found frogs, look for eggs.
3. Once you’ve found some eggs, make some observations. Are the eggs floating at the surface or under the water? Are they attached to plants or not? If they form a clump, is it small or large?
4. Come back again in a week or so. How do the eggs look different?
What’s Happening: Over time, the eggs will become larger and take on the shape of the larva (tadpole, that will eventually be hatched from it. If you simply can’t wait, you can grow your own frog farm using the materials here.
Watch the silent video below to see how to make your own frog farm!
The cartilaginous fishes are a group of about 1,000 species and share many things in common, including the presence of jaws, paired fins, a two-chambered heart, and bodies made of cartilage.
By far the largest group of fish are the bony fish. Eight species of bony fish make up a small group called lobe-finned fish, including the lungfish, a fish with the ability to breathe air, that can even drown if it is kept in water too long.
Another 27,000 species make up the ray-finned fish. Remember from above that there are a total of slightly less than 58,000 species of all vertebrates. It is clear that bony, ray-finned fish are the most common vertebrates.
The lungfish is one of only eight species of lobe-finned bony fish.
As with fish in general, bony fish vary greatly in size and weight, from the 3.3 meter (11 foot) ocean sunfish, topping the scales at over 5,000 pounds, to the tiny pygmy goby, a mere 1.5 cm (0.6 in).
In spite of the variation in size and weight, bony fish have several characteristics that group them together and make them unique amongst the fish.
First, these fish have the ability to regenerate bone from cartilage inside their body. Additionally, ray-finned fish are the only fish that can see in color. Finally, all members of this group have swim bladders, which they are able to add oxygen to or remove oxygen from. This allows the fish to control its density.
Why would a fish want to do this? As you may know, things that are more dense than the fluid they are in will sink, while things less dense than the fluid will float. By changing their density compared to the fluid they are in (water), a fish can cause itself to rise up higher or sink down lower as needed.
Here’s a short video of a puffer fish during its inflating and deflating stages:
There are a number of reasons why fish are important to humans. They provide a source of food, especially for people who live in areas near water. Fishing is also a popular recreational activity, and many people enjoy viewing these beautiful animals in aquariums every day. People have included fish, and legends of half-fish, half-human creatures in stories and legends since ancient times.
Fish are important to more than just humans however. The food web of the oceans and lakes of the world are some of the most diverse on the planet, and the wide variety of fish that live in these ecosystems play a crucial role in maintaining a balance. Humans have recognized this, and have begun to restrict fishing and recreational activities in areas where too much human activity could be harmful to the aquatic ecosystem.
There are 57,739 species of vertebrates. The majority of these vertebrates can be classified as fish. This includes jawless species of fish and cartilaginous fishes. (Those are fish with skeletons made of cartilage, the same material that makes up your nose.)
Fish are almost always ectothermic. This means that the body temperature of fish changes based on the outside temperature. This is different than other animals (including humans) who keep a constant body temperature no matter the temperature outside.
Additionally, fish generally lay eggs, have two paired fins, and have scales. Finally, fish typically have gills which allow them to get oxygen from water, allowing them to breathe while in their underwater habitat.
There are plenty of exceptions to these general characteristics of fish. Tuna, for example, have the ability to warm their bodies so that their body temperature is warmer than the cool water in which they live. Moray eels do not have scales. As you will read in the next section, not all fish have paired fins. Even what seems to be the most “fish-like” characteristic of all, living in water, is not something that all fish have in common.
Mudskippers are fish that spend a considerable amount of time on land, living for several days at a time on mudflats, where they absorb oxygen through their skin in order to breathe.
The group agnatha, also known as the jawless fish, make up one group of fishes. There are about 100 species of jawless fish, which can be placed into one of two groups – the lampreys and the hagfish. Interestingly, although these fish do belong to the vertebrate subphylum, they do not technically have vertebrae. In fact, this group of fish is so different than fish with jaws, it has led some scientists to wonder if they should be called “fish” at all.
Along with their lack of jaws, the jawless fish are notably different than other fish because they do not have paired fins. Agnatha do not have an identifiable stomach, and don’t have a true eye, instead having a light-sensitive eye-like structure. These fish have bodies made of cartilage and have a heart with only two chambers as opposed to the normal four.
Hagfish also produce a slimy substance which has led some people to call them “slime eels,” although they are not eels at all. The Pacific Hagfish is one example of a jawless fish.
I have to admit, one of my all-time favorite animals is the octopus. It’s not only an invertebrate, but amazingly intelligent and can be poisonous (like the blue-ring Octopus shown here) or not.
The octopus is an animal because it’s multi-cellular (more than one cell, so amoeba and protists are not animals), it’s moveable (not like a fungus), and a heterotroph (not a plant). Their life cycle starts with a single cell that divides and leads into a multi-celled adult.
All molluscs have a muscular foot on the bottom, and there are three basic shapes: gastropods (snails and slugs), bivalves (oysters and clams), and cephalopods (octpous and squid).
The Indonesian Mimic Octopus, Thaumoctopus mimicus. This fascinating creature was discovered in 1998 off the coast of Sulawesi in Indonesia, the mimic octopus is the first known species to take on the characteristics of multiple species. This octopus is able to copy the physical likeness and movement of more than fifteen different species, including sea snakes, lionfish, flatfish, brittle stars, giant crabs, sea shells, stingrays, jellyfish, sea anemones, and mantis shrimp.
This animal is so intelligent that it is able to discern which dangerous sea creature to impersonate that will present the greatest threat to its current possible predator. For example, scientists observed that when the octopus was attacked by territorial damselfishes, it mimicked the banded sea snake, a known predator of damselfishes.
Invertebrates are organisms without backbones. Let’s look at two very simple types of invertebrates; Sponges and Cnidarians. Sponges (Phylum Porifera), found in oceans all over the world, are made up of colonies of specialized cells—some help push water through the sponge, some help it feed, some are responsible for reproduction, etc.
They feed by filtering water through its pores. They have flagella on the inside that drive the water through and pick up particulates in the water. In this sense, they are known as sessile filter feeders. Sponges are attached to the ground below them—they are sessile (unable to move). However, sponges can move around at certain times in their lifespan.
Scientists use to think they were plants, but we know now that they are in fact animals. Besides their specialized cells, sponges do not have any organs, nerves, or even true tissues. They are held together through the cooperation of the colony.
Cnidarians (don’t pronounce the ‘c’, so it sounds more like “nay-DAR-ee-ons”) also are radially symmetrical. This means they have a circular body plan such that any way you cut them in half the sides will be equal. There are two basic body forms; polyp and medusa. The polyp is a cup-shaped body—with the mouth facing upward (sea anemones, for example). The medusa is bell-shaped and has a downward-facing mouth (jellyfish, for example). Some can even start in the medusa stage and then move into the hydra stage.
Painful stinging cells, called nematocysts, make the phylum Cnidaria especially notable. Jellyfish and sea anemones are just two examples of these painful creatures. The nematocysts are, in fact, long hollow threads that are used to trap prey. Additionally, these nematocysts are triggered externally, so even if you come across a dead jellyfish don’t step on it!
A Cnidarian with a polyp body plan, a sea anemone, and a Cnidarian with a medusa body plan, a jellyfish. Notice the upward facing mouth of the polyp, and the downward facing one of the jellyfish.
Cnidarians, unlike sponges, have true tissues. They digest their food in a gastrovascular cavity—a large cavity containing digestive enzymes. The digestive cavity also has circulatory functions. Cnidarians, like sponges, can form colonies. Colonies of polyps form the jellyfish the Portuguese Man-O-War. Similarly, colonies of cnidarians form on calcium carbonate skeletons to make coral reefs.
Here we’re going to discuss the differences between three types of worms; flatworms, roundworms, and segmented worms. The word “worm” is not, in fact, a scientific name. It’s an informal way of classifying animals with long bodies and no appendages (no including snakes). They are bilaterally symmetrical (the right and left sides mirror each other). Worms live in salt and fresh water, on land, and inside other organisms as parasites.
The differences between the three types of worms we will discuss depend on the possession of a body cavity and segments. Flatworms have neither a body cavity nor segments. Roundworms only have a body cavity, and segmented worms have both a body cavity and segments.
Flatworms (Phylum Platyhelminthes) have incomplete digestive systems. That means that their digestive system has only one opening. The gas exchange occurs on the surface of their bodies. There are no blood vessels or nervous systems in flatworms. Some are non-parasitic, like the Sea flat worm, and some are parasitic, like the tapeworm.
Echinoderms, meaning “spiny skin”, are radial symmetric marine animals. They are found at all depths—both shallow and deep water. They play important roles in their ecosystems. Despite appearances, they do not have skeletons. The “spiny skin” is, in fact, skin covering a spiny endoskeleton (internal skeleton).
How do echinoderms move? How do they feed themselves?
Echinoderms have a water vascular system responsible for gas exchange, movement, and feeding. This system is an internal network of fluid-filled canals. Depending on the species, they have various ways of getting food into their water vascular systems. Some are filter feeders, while others (such as starfish) are predatory. They use this system in place of gills, heart, and a closed circulatory system. Although they do not have brains, they do have nerve nets responsible for receiving and processing sensory information.
What about their reproduction? They reproduce sexually—with sperms and eggs. Some species provide brainless parental care.
Here’s a super-short quick snippet about starfish:
Echinoderms are found worldwide, and play important roles in their environments. Primarily, they are strong links in the food chain. For example, they control the growth of algae on coral reefs (making it easier for the reefs to filter-feed), and they serve as food for other organisms (otters, for example).
You can do this dissection at home! Here’s a very inexpensive starfish dissection guide and starfish specimen and simple dissection to
ols!
Arthropods, organisms in the phylum arthropoda, are organisms with segmented bodies and appendages on at least one segment. They use these appendages for defense, feeding, sensory perception, and locomotion. We usually see them everyday: fly on the wall, or perhaps moth by the light. The phylum is incredibly divers and the organisms within it have developed numerous adaptations to deal with environments from your kitchen counter to the Amazon!
Arthropoda is the largest phylum in the animal kingdom. Examples of Arthropods include: scorpions, crabs centipedes, insects, and crayfish.
Arthropods are covered my hard external skeletons. When they grow they shed these skeletons in a process called molting. For gas exchange aquatic arthropods have gills, while terrestrial (land-based) arthropods have either a tracheal systems or book lungs. Tracheal systems are air sacs fed by pores in the exoskeleton. Book lungs are gills modified to extract oxygen from air.
Six classes of crustaceans are recognized in the word, and almost fifty two thousand species. Most of them are aquatic. Interestingly, they have a brain in the form of ganglia (connections between nerve cells).
In the phylum Mirapoda (Centipedes and Millipedes), over thirteen thousand species exist! All of them live on land. Some species have fewer than ten legs, while some can have over seven hundred and fifty!
Spiders (a type of Arachnid) are found in the class Araneae and the subphylum Chelicerata. This subphylum includes scorpions, mites, and ticks as well as spiders. Arachnids characteristically have four pairs of legs, a pair of chelicerae (see table at the end of this section), and a body organized into the cephalothorax (a fusion of the head, thorax, and abdomen). There are eleven subgroups of Arachnids.
Insects are not only the most diverse subgroup of arthropods, but with over a million discovered species it is the most diverse group of animals on earth. Although they can’t all be as beautiful as a butterfly, they all play important roles in their ecosystems—just think of where we would be without bees!
The segmented exoskeletons of insects have a hard, inner layer called the cuticle, and a water-resistant outside layer called the exocuticle. Insects are divided into two major groups: winged insects and wingless insects. Air is taken in through structures called spirials, and delivered directly to the body.
Would you like to see a digital circuit do a little division? Well, in this experiment we’ll build on our knowledge and build a divide-by-two circuit using an inverter IC the 4013 D-type flip-flop. This circuit is also the basis for the LED chaser circuit we’ll build later in the series.
Did you know switches are noise? And no, I don’t mean the noise they make when you turn one on or off, I mean they are electrically noisy. What this means is that when a switch changes state is creates a little wave of electrical spike that can cause digital electronics to misread the signal. In this experiment we are going to build a switch bounce analyzer to help see the noise.
Sea angels used to be known as a pteropod (small swimming sea slugs), but now are recognized as pelagic marine opisthobranch gastropod molluscs. Sea angels, also called cliones, live all over the world, both in polar and equatorial seas. Sea butterflies are similar to sea angels, but they also have a shell. Some sea angels even eat sea butterflies, which are slower and larger than themselves!
Sea angels are transparent, gelatinous, and unusually small (the average size is only an inch). Since sea angels are simultaneous hermaphrodites, their fertilization occurs internally and eggs are released to float with the ocean currents until they hatch on their own.
Although sea angels usually enjoy slow movement, as they only beat their winds once a second, they can also put on a burst of speed if they’re catching dinner.
If you have ever gone searching though tide-pools at the beach, you’ve probably seen your fair share of Mollusks. This is because mollusks live mainly in the sea (in the intertidal zone), although some live in freshwater.
Mussels, scallops snails, oysters (from which we get pearls!), and clams are only a few examples of types of mollusks. The mollusk body plan generally involves a muscular foot for locomotion, a body housing organs, a head with eyes or tentacles, and a mantle (which creates the shell). Usually, they absorb oxygen from the water using gills.
Only mollusks have a structure called a radula. Radulae (the plural of radula) are composed mostly of chitin, and can be as simple as a structure used to scrape algae off rocks, to the beaks of octopuses.
Dolphins have complex brains which scientists have discovered are developed enough in certain areas to handle higher-order thinking. Dolphins have shown by their behavior that they know who’s in their group, what status they have, which team they’re on, and each have individual quirks that make it unique from the others. In fact, when a scientist placed a mirror in a tank, the dolphin recognized himself, which made scientists think that perhaps dolphins may have a sense of self.
After a dolphin is specially trained, it has the ability to learn language. Trainers teach the dolphins to tell the difference between statements and questions using gestures and symbols, and they can reverse the order of the words to mean different things (syntax). And dolphins can tell not only the order of the words, but that the meaning has changed as well.
For example, these two sentences have exactly the same words, but in different order:
“Johnny bit the dog.”
“The dog bit Johnny.”
Although the words are exactly the same, the order that you place them in a sentence will give them two entirely different meanings, especially if you are Johnny!
So what does all this have to do with aliens?
Well, I met Dr. Laurence Doyle of the SETI Institute years ago in Mountain View, California, and he studies animal communication as he figures out new ways to detect intelligence in space. It’s a special kind of math that looks at how information is structured, and it’s based on how dolphins communicate with each other.
If you’ve ever heard the statement ‘Are we alone?’ Dr. Doyle answers: ‘No, we’re not alone. There are many animals communicating right here that we don’t understand.’
Scientists are searching for ways to detect alien signals by starting right at home with smart animals all around us. Dr. Doyle says: ‘We’ve been waiting (to hear from aliens) for years, but I thought, ‘We’re not ready!’ We can’t even speak to the intelligent animals on Earth.’
Cool Fact: Did you know that dolphins know what “none” and “zero” means?
Ever wonder what a dolphin trainer really does? These trainers not only train dolphins, but also whales, seals, sea lions, walruses and other marine mammals by using positive reinforcement (sometimes referred to “operant conditioning”). This means that when the animal does the right behavior, there’s a reward. Otherwise, no action or reward is taken. Here’s a neat video that shows how dolphins and killer whales are trained for real:
By completing a dissection, you can see firsthand the anatomy of an animal. Dissecting a roasted chicken (yes, the same kind that you eat) will allow you to investigate the skin, muscle, and bones of this bird.
So, if you’re interested in seeing what allows a chicken to run, fly, and survive, go out to the grocery store and grab some chicken!
Insects are not only the most diverse subgroup of arthropods, but with over a million discovered species it is the most diverse group of animals on earth. Although they can’t all be as beautiful as a butterfly, they all play important roles in their ecosystems—just think of where we would be without bees!
The segmented exoskeletons of insects have a hard, inner layer called the cuticle, and a water-resistant outside layer called the exocuticle. Insects are divided into two major groups: winged insects and wingless insects. Air is taken in through structures called spirials, and delivered directly to the body.
Most insects reproduce sexually and are oviparous (hatch from eggs after the eggs are laid), although some insects reproduce asexually.
You can grow your own butterflies using a premade kit from Home Training Tools!
Dissection in biology provides a hands-on education above and beyond reading a textbook. By seeing, touching and exploring different organs, muscles and tissues inside an animal and seeing how they work together allows you to really understand your own body and appreciate the amazing world around us. And it's not hard - you can dissect a clam right at home using this inexpensive clam specimen with a dissection guide and simple dissection tools! Many doctors, surgeons and veterinarians report that their first fascination with the body started with a biology dissection class.
Materials:
Dissection in biology provides a hands-on education above and beyond reading a textbook. By seeing, touching and exploring different organs, muscles and tissues inside an animal and seeing how they work together allows you to really understand your own body and appreciate the amazing world around us. And it’s not hard – you can dissect a starfish right at home using an inexpensive specimen with a dissection guide and simple dissection tools! Many doctors, surgeons and veterinarians report that their first fascination with the body started with a biology dissection class.
In today’s dissection, we’ll be looking at a starfish. Starfish are members of the phylum Echinoderm. There are many things that make starfish interesting: their rays are symmetrical around their center (this is called radial symmetry), they use seawater instead of blood to transport nutrients through their bodies (this is called a water vascular system), and they move around using tube feet on the underside of their bodies.
Materials
Marsupials are characterized by the presence of a pouch in the female. The pouch contains the mammary glands, which nourish the young. The offspring of marsupials remain in the pouch until they are able to survive on their own. The most well known marsupials are probably kangaroos and koalas, but there are a number of other marsupials, many from Australia.
The thylacine (tasmanian tiger) looked a lot like a short-haired dog combined with a kangaroo. Some folks say that it looked similar to a hyena. The stripes on the rump faded as the animal aged.
There was some sexual dimorphism (the males were slightly larger than females). Normally in marsupials, the pouch opens toward the head of the animal. The female had a pouch that opened to the rear (toward the tail). The thylacine was able to open its jaws very wide – nearly 120 degrees – to show off its 46 sharp teeth.
In today’s dissection, we’ll be looking at an owl pellet. Owls are carnivores, and they eat things like moles, shrews, rodents, birds, insects, and even crayfish. Owls are unable to digest the bones and fur of these creatures, so they regurgitate (or spit up) what are called pellets--small bundles of all the indigestible parts of the owl’s prey.
Owl pellet dissection is an easy, hands-on way to learn about the eating habits of birds of prey. (Owl pellets are the regurgitated remains of an owl's meal.) But don't be grossed out - finding and piecing together the bones inside owl pellets is fascinating work for a young scientist such as yourself! As you dissect the pellet, you'll find skeletons of mice, voles, birds, and more. Synthetic pellets are available for younger children if you'd like to use a substitute.
Dissection in biology provides a hands-on education above and beyond reading a textbook. By seeing, touching and exploring different organs, muscles and tissues inside an animal and seeing how they work together allows you to really understand your own body and appreciate the amazing world around us. And it's not hard - you can dissect a pellet right at home using an inexpensive specimen with a dissection guide and simple dissection tools! Many doctors, surgeons and veterinarians report that their first fascination with the body started with a biology dissection class.
Materials:
It’s been sitting there, and we’ve hardly touched the seven segment display. Well, in this video we are going to use the 4511 seven segment decoder to drive the seven segment display and a keypad to display different numbers. This one is going to be a lot of fun!
Let’s build a digital alarm! In this experiment we’ll modify the circuit from experiment 90, workbook 2, to be a digital alarm. The circuit will countdown and when it reaches zero, the alarm will sound. We’ll also add in a switch so that the alarm part of the circuit can be disabled.
What are the most important animals in the ocean? Whales? Sharks? Giant squids? Think smaller. Arguably, the most important animals in the ocean are found at the bottom of the food chain—the tiny creatures called plankton.
Plankton are microscopic animals that are found all over the world in large bodies of water. They have many different shapes and sizes because they’re not grouped together by how they look, but by their place in the food chain (the bottom). Becoming a planktologist—a scientist who studies plankton—is simple; all you need is a special net.
The plankton nets found in stores are very expensive, often more than $50! Luckily, though, they can be easily made from household items for less than $10.
This is a bonus experiment (the supplies for this project aren’t in the main shopping list), so you’ll find the the supply list of materials you’ll need (below).
The Hester-Dendy sampler makes it easy to collect marine samples. With some simple parts we can construct a device that we will leave in the water for a couple weeks. Then, presto! We have samples ready to study. It’s the no-muscle way to get specimens.
Some creatures to look for in your Hester-Dendy sampler include mussels,different species of algae, insect larva,and any organism that attaches itself to rocks.
To make your handy, you’ll need a set of materials and a workshop (so this is a bonus experiment!) Here are the supplies you’ll need to gather together – you’ll probably find them in the scrap bin in a corner of a workshop:
A “dig” is what archeologists call the process of uncovering artifacts. You can also use this tool in the backyard when investigating a field of bugs, insects, and other invertebrates!
The quadrant is divided into smaller sections by pieces of string tied at regular intervals. Where the string intersects, it creates square sections that can be easily labeled and referred to in a research notebook.
This way, when the scientists return to their labs they can remember exactly where they found everything—a very important part of the science of archeology!
Some animals glow under ultraviolet light. Jellyfish are a prime example of these glowing animals. Under normal conditions, worms do not glow.
However, scientists have been able to genetically alter some worms so that they will glow under an ultraviolet light. To do this, scientists engage in genetic engineering. They inject the gene that makes jellyfish glow into the worm.
Even though jellyfish and worms are very different animals, their genes, like the genes of most living things, are actually quite similar. So, the worms with the injected gene will glow just like jellyfish do.
How does the eye work? If you are amazed as I am about how the different parts of the eye are put together, then this is the lab for you! It's important not only to learn how to take apart video cameras and blenders to find out how they work, but also to be fascinated by how the different parts of living creatures work ... like the eye!
Emperor and Adelie penguins are two species of this flightless bird that live in the Antarctic. Adelies spend most of the year in the water. In October, spring begins in the southern hemisphere, including in the South Pole where Adelies live, and these penguins come onto the land to lay their nests, mate, and raise chicks. The nest of the Adelie is lined with pebbles, and the penguins are very careful about the pebbles they choose. A good pebble can lead to fights if several penguins want it, and a penguin will steal another penguin’s pebble if they are not paying attention.
Male and female Adelie’s work together incubating the eggs and raising the chicks. The female lays two eggs and the male takes the first turn incubating them. After they hatch, in about 35 days, one parent watches them while the other gets food. As the chicks grow, they are left in groups called crèches, so that both parents can hunt for them. By February, as it is getting close to fall in the South Pole, the chicks have fully developed feathers and are ready to leave the land and go onto the ice.
Emperor penguins are the tallest, heaviest, and deepest diving penguins. They also are the only penguins who raise their young during Antarctic winters. The penguins come out of the sea in March and walk, sometimes great distances, to breeding grounds. Most colonies breed on ice, although a few do so on the ground.
In May or early June, the female lays a single egg and transfers it to her mate. The male incubates the egg for two months in a pouch called the brood pouch. Many males will huddle together, taking turns being on the inside and outside, to stay warm. During this time, the females go off to hunt. Like the Adelies, males and females take turns protecting and providing food for the newborns until they get old enough to be left alone while both parents hunt. In December or January, they return to the sea.
Emperors are well designed for their difficult tasks, including surviving the cold, going without food for long periods of time, and making many hard trips to and from the sea. If they go so deep in the water that the pressure becomes greater than their lungs can handle, they can collapse their lungs and slow down their heart rates to save oxygen. They also store additional oxygen in muscle tissue. Research about this oxygen storage ability may help human stroke victims, who also suffer from a lack of oxygen.
Global warming presents severe problems for the Adelie and Emperor penguins. Melting of the ice in Antarctica will reduce the amount of space the penguins have to hunt and live for most of the year. Rising temperatures will also bring more rain and liquid water to Antarctica, which is currently the driest place on Earth. Melted water can destroy the pebble-protected nests of the Adelies. In the Western Antarctic peninsula, where global warming has had the greatest effect, penguin populations have decreased by 80%.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
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A biological net is one of the essential tools of a field biology researcher — you! A bio-net allows you to safely and gently gather samples. Whether you’re studying butterflies or tadpoles a bio-net is the tool to have! Important safety note: Do both of these with parental supervision. Many of the steps are tricky and involve sharp objects.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.
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Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how much you’ve picked up with these experiments and the reading – answer as best as you can. (No peeking at the answers until you’re done!) Just relax and see what jumps to mind when you read the question. You can also print these out and jot down your answers in your science notebook.
Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
Here’s printer-friendly versions of the exercises and answers for you to print out: Simply click here for printable questions and answers.
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
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Let’s see how you did! If you didn’t get a few of these, don’t let it stress you out – it just means you need to play with more experiments in this area. We’re all works in progress, and we have our entire lifetime to puzzle together the mysteries of the universe!
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When you hear “roach” you might not immediately think of something that would make a good pet, but not all roaches are like the cockroaches you might have seen in your house!
Species such as the Orange Spotted Roach (Blaptica dubia) make excellent insect pets: they don’t cost much, they have an interesting life cycle and habits, and they do not require much effort to care for. Their average lifespan is about 18 months and you’ll be able to learn more about their fascinating life cycle (from egg to adult) if you allow them to breed!
A pet roach isn’t a pest?
It may seem like all roaches are pests, but of 4,000 species, only 4 or 5 live in homes and are considered pests (such as the American cockroach). Most roaches live in tropical environments far from domesticated areas. They are very different from the kind of household pest you might think of when you hear “roach.”
You might think roaches would make pretty boring pets, but they are surprisingly fast and fun to watch. You can learn a lot about insect anatomy and what makes roaches unique by taking care of them. The species that make good pets do not smell, are not noisy, cannot fly, and generally are very easy to clean up after. They typically are most active at night, because they prefer a dark environment like they have on the floor of the rainforest. They love to hide during the day, but will come out to eat.
Can I touch them? They are meant to be pets, and are perfectly safe to handle. A good environment for roaches is a small aquarium or plastic cage with cardboard egg cartons for them to hang out in. You might try picking up one of the egg cartons where a roach is hiding, then either hold the carton so the roach can crawl around on it or let the roach crawl in to your hands. Hold out your hand, keeping your fingers together and flat. Let the roach crawl on you, then slowly lift out your hand and cup it slightly. Remember to wash your hands afterwards, using warm water and soap. Although these insects don’t cause diseases in humans, they may be carrying harmful bacteria, so it is important to wash your hands so that you don’t get sick.
How long do they live? It varies, but species like Orange Spotted Roaches have a lifespan of 18-24 months. The female gives live birth, usually to 20-30 babies at a time. The babies reach maturity in 3-4 months after they are born. While they are growing into adults, they will molt – shedding their outer hard shell, or exoskeleton, and then growing a bigger one.
Will my roaches breed? If you get one male and one female, there is a good chance that they will breed under the right circumstances. If you do not want baby roaches, keep the temperature of the habitat around 70 degrees, or normal room temperature. Adult Orange Spotted Roaches will be fine at this temperature, but they will not mate because their young need higher temperatures to survive. If you would like to see the complete life cycle, you will need to ensure that their habitat has enough heat and humidity.
Feeding Time: What does a pet roach eat? They are omnivores – they eat plants and meat. So a good basic diet contains protein from plants and animals and fiber from grains. You can buy special roach food for them and then to supplement their diet give them fresh fruits and vegetables once a week. Try putting a slice of apple, banana, orange, carrot, potato, or zucchini, or a few spinach leaves in a shallow plastic dish and put it in their habitat. This will provide vitamins and minerals for your pets. Be sure to take the uneaten produce out of the habitat within 48 hours to prevent mold from growing, or attracting ants or fruit flies. A great roach diet would be dry food every day and a fresh food supplement once a week.
Be sure to keep their water dish full. Roaches can live a long time without food, but usually only survive three days without water. The water dish also helps make their habitat more moist and humid. For easiest care, use water absorbent crystals that hold water. You can keep an airtight container of prepared water crystals in a cool place, and add another crystal to the water dish whenever needed (usually every 2-3 days).
If the habitat is hot and humid, the roaches will be more active, which means they will also eat and drink more.
Cleaning Time: You should periodically clean out your pet roach’s habitat to make sure there is no mold growing. Cleaning out the habitat takes only a few minutes and will prevent any bad odors coming from your insects. When is the right time to clean the habitat? When you see small dark roach droppings starting to collect on the bottom, you should clean the habitat out. Usually about once a month is a good time. The minimum should be once every other month.
To clean out the habitat, first remove the roaches. Place them in a container that has smooth sides to prevent them from climbing out. Pick up the roaches one at a time and transfer them to the carton or other container. If a roach is hiding in an egg carton, carefully lift out the carton, then let the roach crawl off into the container or onto your hand. Wash your hands with soap and warm water after touching the roaches.
Take the food and water dishes out, as well as the egg cartons, and place them on paper towels. Rinse the container out and then wash it with a solution of 10 parts warm water to 1 part bleach. Rinse the container again and dry it thoroughly. Place the food and water dishes back in the container. If the cardboard egg cartons seem clean, put them back into the container. Don’t use foam egg cartons. You can also use cardboard tubes in different sizes (mailing tubes, toilet paper tubes, or wrapping paper tubes cut down to shorter lengths) so the roaches can crawl in them. When you’re finished cleaning, throw the used egg cartons away as well as the paper towels. Transfer your roaches back to their habitat, using a flat hand so they can crawl off.
Building a Roach Ranch: If you decide to get a pet roach, you can create a habitat to be as simple or creative as you like. If you wish to make a more natural-looking habitat for your pet roaches to enjoy, you can buy peat moss or coconut husk mulch from a pet store (in the Reptile section). Put in a layer of moss or mulch (about one inch), then add pieces of bark for the roaches to climb on and hide under. This type of Roach Ranch will be similar to the Orange Spotted Roaches’ natural environment in the rainforests of South America.
You can make a Roach Ranch out of cardboard, which can easily be thrown away when it gets dirty. Make a multi-level mansion for your roaches by cutting 3-4 identical shapes (square, rectangle, L-shape) from cardboard. Put separators in between each level – use stacked cardboard strips that are one inch wide and several inches long. Each level should be separated about ½” or three strips of cardboard stacked together. Use Elmer’s glue to attach the separators and flat levels, and let it dry completely (may take up to 24 hours) before putting it in your roach habitat. Add cardboard tubes or crumpled newspaper to complete your Roach Ranch. Remember that it will be easier to clean if roach droppings can fall freely to the ground. When you clean your habitat, check to see if your Roach Ranch is staying clean. Throw away any parts that have been well-used and add new cardboard material for the roaches to climb.
How many of these items do you already have? We’ve tried to keep it simple for you by making the majority of the items things most people have within reach (both physically and budget-wise).
You do not need to do ALL the experiments – just pick the ones you want to do by first checking out the experiment videos. Note the activities that you already have the supplies for and start with those. When you are ready for more, make a note of the supplies from this list.
Shopping List for Unit 17: Click here for Shopping List for Unit 17.
One place where bacteria can be found is on your teeth. This is why it’s so important to brush well. Don’t believe me? Then this experiment is for you. You’ll need to gather your materials and make sure you have a toothbrush and microscope nearby.
This is important because prokaryotes are incredibly common and have a huge impact on our lives. You may already know some of the ways bacteria can be harmful to you, and this is certainly important information. Scientists have used knowledge of prokaryotes to create medications, vaccines, and healthy living habits that have led to a healthier life for billions of people.
If you’re thinking sunlight, you’re right. Natural light is best for plants for any part of the plant’s life cycle. But what can you offer indoor plants?
In Unit 9 we learned how light contains different colors (wavelengths), and it’s important to understand which wavelengths your indoor plant prefers.
Plants make their food through photosynthesis: the chlorophyll transforms carbon dioxide into food. Three things influence the growth of the plant: the intensity of the light, the time the plant is exposed to light, and the color of the light.
When plants grow in sunlight, they get full intensity and the full spectrum of all wavelengths. However, plants only really use the red and blue wavelengths. Blue light helps the leaves and stems grow (which means more area for photosynthesis) and seedlings start, so fluorescent lights are a good choice, since they are high in blue wavelengths.
If you have ever seen mold growing on an old loaf of bread or eaten a mushroom, you have encountered a fungus. Fungi (that’s the plural of fungus) are a group of organisms, or living things, that are all around us. Mold on bread and mushrooms on pizza are both examples of fungi.
Fungi have an important job. They help break down other material, so that living things are able to grow in soil. This helps make nutritious foods for other organisms. Fungi are needed for life!
Do you think mushrooms are plants? Scientists used to think that all fungi were plants. Now they know that there are some very important different between these two groups of organisms. One of the most important differences is that plants are autotrophic. This means that they can make their own food, just by using the sunlight. Fungi can’t do this. They have to “eat” other living things in order to get the energy they need. This is called being heterotrophic.
Living things are all around us. Sometimes the living things we notice the most are animals, whether its birds chirping in the trees, our pet dogs, or even our fellow human beings. However, most living things are not animals - they include bacteria, archae, fungi, protists, and plants. These organisms are extremely important to learn about. They make life possible for animals, including human beings, by keeping soil ready for growth, and providing oxygen for our survival. No life would be possible without these remarkable organisms.
The prokaryotes, bacteria and archaea represent an amazingly diverse group of organisms only visible when one looks under a microscope. These single-celled organisms obtain energy and reproduce in a variety of ways.
Though some bacteria are harmful, causing disease, many are very helpful, providing the nitrogen we need to live and aiding in digestion. Archaea have been found in some of the most extreme environments on the planets, including environments that are remarkably hot or salty.
Ah-chooo! Influenza (the “flu”) is when you get chills, fever, sore throat, muscle pains, headaches, coughing, and feel like all you want to do is lie in bed. The flu is often confused with the common cold, but it’s a totally different (and more severe) virus.
The flu is passed from person to person (or animals or birds) by coughing or sneezing. With plants, it’s transmitted through the sap via insects. In the case of birds and animals, the flu is usually transmitted by touching their droppings, which is why hand-washing is so important! In addition to soap, the flu virus can be inactivated by sunlight, disinfectants and detergents.
Birds, people, plants, and microscopic organisms need to know where they are as well as where they want to be. Birds migrate each year and know which way is south, and plants detect the sun so they can angle their leaves properly. People consult a map or GPS to figure out where they are.
Magnetotactic bacteria orients itself along magnetic field lines, whether from a nearby magnet or the Earth’s magnetic field. It’s like having a built-in internal compass.
All living things need a way to get energy. Bacteria get their food and energy in many ways. Some bacteria can make food on their own, while others need other organisms.
Some bacteria help other living things as they get energy, others hurt them while they get energy, and still others have no affect on living things at all.
Some living things, or organisms, are able to make their own food in a process called photosynthesis.
In this process, the organism turns energy from the sun into energy that can be used for energy. Organisms that get their energy from photosynthesis are called autotrophs. Some bacteria get their energy this way.
Some bacteria, called chemotrophs, get their energy by breaking down chemical compounds in the environment, including ammonia. Breaking down ammonia is important because ammonia contains the element nitrogen.
Bacteria have a bad reputation. Walk down the cleaning aisle of any store and you’ll see rows and rows of products promising to kill them. There are definitely some bacteria that cause problems for people, and we’ll talk about them soon, but we are going to start off positive, and talk about the many ways bacteria can be helpful.
First, decomposers help control waste. Without these bacteria, the amount of waste in soil would quickly make the soil a place where nothing could grow. Bacteria are even used in sewage treatment plants to treat our waste. Decomposers also help provide organisms with nitrogen, as was discussed earlier.
If your kitchen is like most kitchens, you probably have cabinets for cups and pots and pans, along with drawers for silverware and cooking utensils. You might also have a drawer you call the “junk drawer.” The things in this drawer aren’t actually “junk.” If they were, you’d throw them away. Instead, things usually get put here because they just don’t fit anywhere else.
You might be surprised to learn that the system for classifying organisms has its own “junk drawer.” It’s called the protist kingdom. Its members, like the contents of your kitchen junk drawer, are important, but don’t fit nicely in one of the other kingdoms.
Broadly, protists can be classified as animal-like, plant-like, or fungus-like. It is important to remember that being “animal-like” does not make a protist an animal. Such and organism, like plant-like or fungus-like protists, are members of an entirely different group of living things.
