And we are on to Kingdom number four – Kingdom Animalia.
Animals are everywhere, from the highest mountaintop to the deepest ocean and from the coldest tundra to the most arid desert. We can’t possibly look at every animal in creation, so we will especially focus on ten or eleven selections, beginning first with theinvertebrates. The vast majority of animals are invertebrates – animals with no backbones. How many invertebrates can you think of in ten seconds?
Did worms make your list? We will study examples of worms from two different phyla to start – phylum Platyhelminthes (the flatworms) and phylum Annelida (the segmented worms). Here are a few words you should become familiar with before we begin our discussion: Click off the “both sides” button in the top right before you begin. After you guess the word, click on the flashcard to check yourself.
Let’s start by first examining a small flatworm – the planarian. Planaria usually live under rocks or decaying leaves in freshwater ponds, streams and puddles. They vary greatly in size and color but are most often small and gray/black. Here is a diagram of a typical planarian – can you see why it is called a flatworm?
Notice the funny mouth on the ventral side in the middle of the organism. Planaria are carnivores who eat by Study the diagram and then watch this video to see a planarian swimming. Make sure to watch for the eyespots and the tubelike pharynx.
Do you remember from the video what type of symmetry this organism has? Watch it again if you missed it.
We are going to look at both a microscopic view of a planarian and also observe a live specimen. If you can’t obtain a live specimen, you can answer these questions after watching the above video. But live planaria are fun to work with and are worth the trouble of obtaining. You can order live organisms and prepared slides inexpensively from Home Training Tools. Sunesis Seminar students will do the observations in the Seminar.
First let’s measure the planarian. Using a pipette or eyedropper, suck up a drop of water containing an organism from the culture jar and squirt it onto a small styrofoam plate. Wait for the worm to stretch out and measure the length in millimeters. Record the measurement on the Planaria Observation Sheet.
Observe the planarian for five minutes using a hand lens. Can you see the eyespots? Locate the anterior and posterior ends. Does the planarian seem active or passive? How does it move? Does it swim or creep? Where in the dish does it spend most of its time? Make a current in the water with a pipette or eyedropper. How does the planarian react? Fill out the table on the obervation sheet.
You can discover if your specimen is right-handed” or “left-handed” by flipping it over on its dorsal sideand watching to see which way it recovers. If it rolls to the right, it is right-handed. If it rolls to the left, it is left-handed. Do five trials to determine the handedness of your organism and fill in the data table on your observation sheet.
Place a very tiny piece of food into the dish with your planarian. Observe the planarian’s reaction. How does it eat its food? Where is its mouth? Write your observations on the lab sheet.
Is your bread mold growing yet? In a few minutes we will look at it under the microscope…but first, let’s learn a little bit about bread mold, a fungus in phylum Zygomycota.
Print this picture and color along while we talk about the structure of bread mold.
To most people, bread mold looks like gray fuzz. But up close, as you can see, bread mold looks like thin stalks capped by roundish balls called sporangiophores. Spores are formed inside the sporangiophores, and then they are released and drop, blow away, and land on other surfaces where new molds will grow. Color the sporangiophores ORANGE. The sporangiophores sit atop thin stalks called aerial hyphae. Sometimes these hyphae lengthen, run along the ground, and form new filaments. Color the aerial hyphae (the stems) BROWN and the stolons (that run along the ground and join two groups of aerial hyphae together) RED. The rhizoid hyphae makes up the rootlike mass of fungus under the surface. Color the rhizoid hyphae BLUE.The rhizoids, the sporangia, and the stolons are all types of hyphae. So basically Zygomycotes have three types of hyphae.
Most zygomycotes aren’t dangerous, even if you eat them. But they can sure make your food look unappetizing…which reminds me that it is time to check out your bread mold under the microscope. Is it growing yet?
Make a wet mount slide by scraping up a tiny bit of mold with a toothpick. Observe your specimen on all powers and sketch what you see.
Study for your test with these FLASHCARDS and email me when you are ready! Unclick the “both sides” box in the top right corner before you begin.
Well, we’ve looked at two of the five kingdoms so far – the bacteria of kingdom Monera and the one-celled creatures of kingdom Protista. Now we are on to the third – Kingdom FUNGI.
You probably already know a few things about fungi. For example, you probably know that a mushroom is a type of fungus. But what else do you know? Click andPLAY THIS GAMEto find out.
Do you recognize any other fungi from these pictures?
We don’t, of course, want a moldy fungus growing on our bread. And some fungi can cause serious diseases. But others are useful and important…yeast, for example, makes bread rise. Some important medicines such as penicillin are derived from fungi. (Watch the video on Alexander Fleming in the sidebar to learn more). Other fungi are important in the manufacture of cheeses and wine.
I want to spend a few minutes learning about some general characteristics of fungi, but first we need to start growing a sample fungus to look at later. It will take five days or more to grow, so, fellow mycologists, start it now:
You will need a slice of bread (freshly baked bread works fastest, but any bread will do – the fresher the better) and a self-seal plastic bag. Sprinkle the bread with water. Leave it uncovered for several hours, and then sprinkle on a little more water. Place the bread into a plastic bag. Seal the bag, trapping in a small amount of air. Place the bag in a dark place at room temperature (such as under the kitchen sink.) We’ll pull it out in a few days to check for any fungal growth.
Okay, now we are ready to talk about some characteristics of typical fungi. In a few minutes we will look more specifically at three sample phyla in this kingdom, but all of the phyla have some things in common, so lets start by pointing out the similarities. For example, most fungi, no matter to what phylum they belong, are heterotrophic, specifically saprophytic. Do you remember what “saprophytic” means? Saprophytic organisms, also known as decomposers, derive their nourishment by breaking down dead or decaying organisms. In fact, fungi are the most important decomposers in the world. If it weren’t for the fungi all around us that are constantly decomposing them, we’d be buried in dead leaves, animal waste, and trash.
Fungi break down their food by secreting special chemicals into the food so that it will digest. Then they absorb the digested food into their bodies. This type of digestion is called “extracellular digestion” because it takes place outside of the organism. In most fungi this digestion is performed in a structure called the mycelium. We will look more closely at the mycelium when we examine specific fungal phyla.
Most fungi reproduce by producing spores, tiny oval-shaped structures which are designed to survive even in unfavorable conditions. Mushrooms produce their spores in gills or pores – so, before we look more closely at spores, maybe it’s time to look at the structure of mushrooms in a little more detail. Print the picture below, and follow the instructions to color:
Mushrooms are members of the fungal phylum Basidiomycota. The main part of the mushroom, unlike what you might expect, is the underground mycelium which performs the extracellular digestion. The mycelium is made up of many individual rootlike strands called hyphae. Color the mycelium BROWN. The stalk of the mushroom is called the stipe. Color it GRAY. The cap is the umbrella-shaped cup on the top of the mushroom. Color it RED. Underneath the cap the reproductive spores are formed – either in slits called gills or behind holes called pores. Color the gills in the drawing PINK. Do you see the flap of tissue attached near the top of the stipe? This structure is called the ring. When mushrooms newly sprout, the cap and stipe are inside a thin covering of tissue called the veil. As the mushroom grows it breaks through the veil and sometimes leaves a rim of fleshy tissue surrounding the stipe, like you can see in the picture. Color the ring BLUE.
Now see if you can find a few sample live-growing mushrooms to study – or buy some at a grocery store.
Let’s look at the external anatomy first. Print this chart and fill it out as you examine each specimen. Wear gloves if you gathered your samples from outdoors – mushrooms can be toxic! Use a tape measure to measure the cap width and stalk length. Use tweezers and a magnifying glass to check out the gills. See how many specimens you can find to examine. Scan your chart and send it to me and I will publish it on our website.
The next thing we want to do is look at some spores under a microscope. The easiest way to gather some is to make a spore print. To do this you will need a mushroom cap with open gills (not pores). Older mushrooms work best. Break off the stipe and lay the mushroom cap, gill side down, on a sheet of white paper. Cover the cap with a glass or bowl and leave overnight. In the morning it should look something like this:
Scrape up a bit of the residue with a toothpick and tap onto a clean slide. Add a drop of water and a coverslip and check it out under your microscope. Don’t forget to draw what you see on a sheet of microscope paper.
Puffballs are also members of phylum Basidiomycota. Can you see the spores in this video?
Members of phylum Basidiomycota are obviously multicellular, but some fungi are unicellular. Yeast, a member of phylum Ascomycota, is an example of a unicellular fungus. Yeasts often reproduce by a process called budding, in which their cell walls swell to form a pouch, fill with cytoplasm, and eventually pinch off to form new yeast cells.
See if you can see any budding cells in this short video, and then lets look at some actual yeast cells budding.
To make a wet-mount slide you will need a packet of active dry yeast like the kind used in making bread. The spores in the packet will grow into yeast cells when mixed with water, so you will need some warm water to “wake up” the inactive spores. You will also need some sugar. The reason bread dough rises is that the yeast feeds on the sugar in the dough and breaks it down into alcohol and carbon dioxide. Carbon dioxide is a gas, and when the gas tries to bubble out of the dough lump, the lump grows larger due to the gas bubbles trapped inside. Interestingly, no oxygen is necessary for this process to occur – so it is an anaerobic process. We call this fermentation. You can understand now why fungi are also used to make wine and beer. Fermentation not only produces carbon dioxide gas but also alcohol.
Now, here’s what we will do:
In a glass or measuring cup, mix your packet of yeast into a cup of warm water.
Add a tablespoonful of sugar.
Wait five to ten minutes. What do you see? You should see bubbles form – what do you think they are?
Place a drop of the solution onto a clean slide and cover with a cover slip.
Start on scanning power, and then observe on medium and high powers. Draw what you see on a sheet of microscope paper. Look for oval shaped cells that are attached in the middle (like the picture above).
Wait thirty minutes and observe again. What differences do you see? Can you find any chains of yeast cells?
Yeast isn’t the only edible member of phylum Ascomycota. Have you ever heard of truffles? Not chocolates, but fungus. CLICK HEREto learn about members of this fascinating phylum.
Ready to see how much you remember so far? Before we check out our bread mold, CLICK HERE for a crossword puzzle to test yourself:
While the protozoans are some of the most interesting organisms in creation, algae are perhaps the most beautiful. Algae are protists that produce their own food, usually by photosynthesis. They live in all natural bodies of water and produce most of the oxygen required for our life on earth. They also are the most important source of food for many water-dwelling organisms. People eat algae too, and we also use it to thicken our food and add it to our makeup and medicine. Check the labels of the food and toiletries in your house. Do you see carageenan, alginate, or beta carotene listed as one of the ingredients? If so you are eating algae. Here is a list of foods that might contain algae:
Brownie mix
Ice cream
Toothpaste
Mayonnaise
Pet food
Salad dressing
Chocolate milk
Vitamins
…see how many you can find and send me your list!
Algae is very diverse. Check out these pictures:
It’s hard to believe that these are all examples of algae. We could spend months learning about all the different kinds of algae, but lets just concentrate on looking more closely at one particular unicellular variety: Spirogyra, which is in phylum Chlorophyta.
Spirogyra gets its name from the long spiral chloroplasts that twist through the cells. Do you remember the function of chloroplasts? They store chlorophyll, which is a green pigment many autotrophs use in photosynthesis. They live in colonies of long strings of cells called filaments. If you look closely you can see the cell wall that separates each individual cell from the next. Print and color this diagram of a typical Spirogyra:
Color the cell wall pink.
Color the long spiral chloroplast green.
In the middle you can see the round nucleus. Color it blue.
If you have a prepared slide of spirogyra, take a look at it now. Spirogyra is fairly large, so you will need to observe your slide on medium magnification and adjust your fine focus to see all through the organism. Also check your pond water sample for Spirogrya – it is commonly found in almost all pond water. Even if you don’t see any Spirogyra, you will likely see other types of algae – look closely at anything green. It’s probably algae!
The last protozoan we will look at in detail is the paramecium, which is a member of phylum Ciliophora.
Like the others we have studied, paramecia are unicellular heterotrophs that like to live in still water. They are large compared to other protozoans and can often be seen without the aid of a microscope. You can barely see them in this picture, but paramecia are covered with tiny hair like projections called cilia that enable the paramecium to move. Look very closely at this video around the edges of the paramecium and you can see the cilia wiggling:
Print the diagram below and color the cilia black, and then follow along as we discuss the organelles and other structures found in a typical paramecium.
As you may have noticed in the video, the paramecium, unlike the amoeba and the euglena, does not change its shape when it moves. This is due to the very stiff outer pellicle that surrounds the cell membrane and holds the organism’s shape. Color the pellicle light blue.
Paramecia are heterotrophic. This means that they cannot make their own food and must obtain their nutrition from algae and other tiny microorganisms. How does the food get inside the cell? Well, each paramecium has an opening in its pellicle called an oral groove that is lined with cilia. The cilia sweep bits of food through a hole called a mouth pore into a gullet, where food vacuoles are formed. The vacuoles break away from the gullet and are suspended in the cytoplasm until the food is digested. Find the large oral groove on the top of the diagram and color it orange. The thin tunnel at the bottom of it is the gullet – color it dark blue. Color all of the food vacuoles, including the one still attached to the gullet, light brown. Then watch this short video of a paramecium eating. Watch how the food vacuole gets larger and then eventually breaks off into the cytoplasm:
Waste is eliminated through an opening called the anal pore. In the diagram, the anal pore looks like a small sunburst ( do not get it confused with the large contractile vacuole). Color the anal pore dark brown.
On the left side you can see the large nucleus. But because paramecium are so large, a smaller nucleus, called the micronucleus, is also necessary. The micronucleus, above the large nucleus, is involved in reproduction. The large nucleus, called the macronucleus, is in charge of making proteins, digesting food, and other processes that help the paremecium use energy. Color the macronucleus red and the micronucleus pink.
Contractile vacuoles, as you know, regulate the amount of water allowed in the cell and get rid of the excess. The one in the diagram looks like a large sunburst. Color it dark green.
Do you see the raindrop-shaped trichocysts all around the paramecium, right inside the pellicle? These are sort of like protist armor – the paramecium can shoot tiny threads out of the trichocysts to trap predators or to make themselves look larger in order to scare them away. Color the trichcysts purple.
That leaves the cytoplasm. Like amoeba, paramecium have two types: thicker endoplasm near the center, and thinner ectoplasm near the outer edges. Color the endoplasm yellow and leave the ectoplasm clear.
If you have a prepared slide of a paramecium, take a few minutes to check it out now. Draw and label what you see on a sheet of microscope paper. Try to find as many of these structures as you can: Macronucleus, micronucleus, food vacuole, contractile vacuole, oral groove, gullet, pellicle, cilia.
Can you guess why paramecium are placed in phylum ciliophora? It is the phylum for all protozoans that move using cilia. Here is a video of another member of this family: the Stentor. Watch for the cilia moving near the tops of the organisms.
How many of these questions can you answer without looking back? Don’t forget to send me your answers!
To what kingdom and phylum do paramecia belong?
Are paramecia heterotrophic or autotrophic? Are they unicellular or multicellular?
How do paramecia move?
Where do paramecia live?
What keeps a paramecium from changing its shape like amoeba do?
Why does a paramecium have two nuclei?
What does a contractile vacuole do?
How does a paramecium get rid of waste?
What do the trichocysts do?
Then TAKE THIS QUIZ to see how much you’ve learned so far about protozoa!
Alot different from the amoeba, huh? Although they are similar to amoebas in that they are unicellular protists who like to live in quiet ponds and puddles, they have some very important and interesting differences.
First of all euglenas, which are classified into phylum Mastigophora, have a stiff pellicle outside the cell membrane which is far less flexible than the cell membranes of amoebas. So while amoebas can move by randomly changing shape, euglenas keep basically the same oblong shape. They can move in and out a little bit, scrunching long and then round and fat like an earthworm, but most of their motion is through the use of their flagella. The flagella is like a little motorized tail attached in a open reservoir on the front end. The flagella pulls the euglena through the water by spinning around. Print the diagram below so that you can color the pellicle blue, the flagellum black, and the reservoir gray.
Watch this video of a euglena in motion before you continue:
Euglena are both autotrophic and heterotrophic. They have special organelles called chloroplasts which trap sunlight that they use to make their own food just like plants – but they can also absorb food from the water in which they live. In the diagram the chloroplasts look like rods. Color them green. To help them find the sunlight they need, they have special eyespots which are sensitive to bright light. In the diagram the eyespot is near the flagella. Color it red. If not enough light is available, euglenas absorb the remains of other dead organisms through their cell membranes.
The nucleus is near the center with the nucleolus in the center of it. Recall that the nucleus holds the DNA. Color the nucleus purple and the nucleolus pink.
Near the flagella is the sunburst-shaped contractile vacuole – do you remember its function? It controls the amount of water inside the euglena, removing any excess so that the organism will not explode. Color the contractile vacuole orange.
The only thing left to color is the cytoplasm. Let’s color it light yellow.
To what kingdom and phylum do euglena belong?
The ability of some organisms to make their own food using sunlight and chlorophyll is called “photosynthesis”. In what organelle does the photosynthesis take place in a euglena?
Where on a euglena is the flagella?
Explain two ways in which euglena obtain their nutrition.
What is the function of the eyespot?
What is the function of the nucleus?
What would happen if a euglena did not have a functioning contractile vacuole?
Take a few minutes to check out a prepared slide of a euglena. Draw, on high magnification, a euglena. Try to find the eyespot, the contractile vacuole, the pellicle, a chloroplast, the flagellum, and the nucleus.
Before we move on to paramecium, I want to show you an example of a member of phylum Mastigophora that lives in colonies rather than individually. Here is a picture of a colony of Volvox:
A Volvox is a colony of microscopic individuals, each with two flagella, which join together to create a spherical rolling lattice. Like euglena, volvox are photosynthetic.
If you have a prepared slide of Volvox, check it out now and draw what you see.
Protists are usually divided into two subgroups: the more animal-like protists are called PROTOZOANS and the more plant-like are the ALGAE. Each subgroup has some typical characteristics:
We are going to look extensively at some typical protozoa first, and we are going to start with AMOEBA, a unicellular member of phylum Sarcodina. Amoebas are commonly found in pond water but can live in all kinds of warm, moist environments: salt water, wet soil, and even inside people. Amoebas can be pathogenic. Drinking water cotaminated by amoebas can cause digestive system ailments including cramps and diarrhea, and sometimes even fatal illnesses in humans.
Amoebas are fairly large as far as protists go. Some can even be seen without a microscope if you look very closely.
As you already know, all protists, including amoebas, are eukaryotic, so they contain membrane bound organelles. Let’s start our discussion of amoebas by looking at the structure of the organisms and the organelles you typically find within their one cell. Here are some picture of typical amoebas:
Notice that the amoeba in each picture has a different, random shape. That is a typical characteristic of the amoeba – a very flexible cell membrane which enables it to change its shape easily. And in fact this is where it gets its name – from a Greek word meaning “change”.
Print this diagram of an amoeba and color its parts as we discuss them, beginning with the flexible cell membrane which you should color red.
Those strange-looking fingers that you see protruding off of the edges of the amoeba are called pseudopods, and they actually have several very important purposes. The word “pseudopod” means false foot, and in fact one of the functions of a pseudopod is the same as the function of our feet – to move. Do you remember the name of the jellylike fluid found inside of all cells? Just as it does in other types of cells, cytoplasm fills the inside of unicellular organisms. There are two types of cytoplasm in an amoeba cell: thick, dark endoplasm near the center and thin, watery ectoplasm near the edges. Amoeba move by filling their pseudopods with ectoplasm, enabling them to creep slowly along in the direction the pseudopods extend. Color each of the amoeba’s pseudopods yellow. Color the endoplasm (the dotted portion) blue, and leave the ectoplasm clear. Here’s a video showing this motion:
The pseudopods are not only used for motion but also for obtaining food. Amoebas are heterotrophic and comsume food by the process of phagocytosis. Two pseudopods extend out and around a bit of food and attach together, forming a sac called a food vacuole where the food is held. Later the lysosomes will digest the engulfed food. There are a number of food vacuoles throughout the cytoplasm in the diagram and one newly-formed one on the bottom. Color all the food vacuoles brown.
Before we continue with coloring, watch this video of an amoeba engulfing a tiny protozoa:
Do you see the large nucleus in the upper left? The nucleus, as you remember, contains the amoeba’s DNA. The nucleus also is involved in reproduction – amoebas reproduce by splitting in two in a process called binary fission. Color the nucleus purple.
Food vacuoles aren’t the only kinds of vacuoles protists can have. Amoeba also have contractile vacuoles, which are sacs that suck out extra water and carry it to the edges so that it can be released. This is very important – without contractile vacuoles, amoeba could explode from too much water inside. The contractile vacuole in the diagram looks like a sunburst or a flower. Color it orange.
How carefully did you read? See if you can answer these questions:
How does an amoeba move?
Where in an amoeba will you find the DNA?
How does an amoeba reproduce itself?
What are the fingers of cytoplasm called that help the amoeba move and eat?
To what kingdom and phylum do amoeba belong?
Now would be a good time to check out a prepared slide of an amoeba, if you have or can borrow one. Make sure to draw what you see on microscope paper and label as many organelles as you can find. Look for a pseudopod, cytoplasm (both ecto and endoplasm), food vacuoles, contractile vacuoles, a nucleus, and a cell membrane. Send me your finished work!
One kingdom down, four to go. Let’s take a look next at the other kindgom that is mostly made of of unicellular organisms…Kingdom Protista.
Take a look at some sample members of Kingdom Protista: See how diverse they are? Some consist of only one cell and others, like the algae on the bottom row, are multicellular. Some are heterotrophic and some are autotrophic. Some can move on their own and others must rely on the current of the water in which they live to move them. Some live alone and others live in groups, called colonies.
We are going to spend some time looking closely at many of these examples over the next few lessons. Let’s see if we can get a real-life glimpse of a few live protists before we begin.
You can order live protists from a science supply company like HomeScienceTools, but the best way to observe a good variety of protists is to collect your own. They all require an aquatic environment, so the best place to gather a sample of protists is in a local pond or other stagnant water source, like a horse trough or rain puddle. Collect some pond water, get out your microscope, and see if you can find some microscopic protists. The best way to collect the water is with a long ladle. Scrape some water from the bottom of the pond and place it into a jar. Try to choose a warm, dark spot. Make sure to get a little mud from the bottom into your sample.
If you want, you can culture your sample for a few days first. Culturing is a means by which scientists try to increase the number of organisms in a sample by feeding them and providing environmental conditions the organisms like. We cultured bacteria in our cupcake paper bacteria food. Pond protists prefer a dark warm environment with lots of food, so if you want to culture your organisms first add a little food to the jar, like a tiny bit of hardboiled egg yolk or a few grains of uncooked white rice. Then wrap the jar in aluminum foil to keep out the light, poke a few holes in the lid for air, and leave it in a warm place for a few days (like the laundry room).
When you are ready to look for protists, prepare a wet mount slide. Use an eyedropper to draw up a drop of your culture from near the bottom of the jar. Drop the sample onto the center of a clean slide. It is better if there is a bit of food or dirt in your sample so that you can focus the microscope accurately. Carefully add a coverslip.
Begin scanning once you have focused on the microscope on a bit of food or dirt. Scan on low power until you find an orgaism to watch. Once you locate one you can increase the magnification. Be patient. If you can’t find something after a few minutes of looking, try another slide. Try to draw what you see on a sheet of microscope paper. Don’t worry if you can’t find any specimens – although it is great fun to watch actual microorganisms on a slide, we will have a chance to observe some short videos of protists and you will hopefully look at some prepared slides of the organisms we study.
USE THESE FLASHCARDSto help you study for the next test. Click “start study session”, and then “random” order and the”definition then term” option before you begin. Then hit “flip card” to check your answer, and “next card” to advance to the next question. Email me when you are ready for the test!
foodklutz
Sunesis Science 