To make the body work right, cells have to do three things: perform specialized functions, cooperate, and communicate. When they don't, people get sick.
- Explain how many different cells, organs, and organ systems have to work together to keep the body healthy.
- Explain in detail how a specific disease affects the body's proper functioning.
Organ Systems Sort
You've got a lot of nerve! ... I mean nerves, and a whole lot of other organs too! All these organs work together in groups called organ systems.
Each organ system has a function, and all the organs in that system help
it perform that function.
For example, your digestive system is made up of many organs,
including your mouth, stomach, and intestines. All the organs in the digestive
system work together to help you break down food into particles that can be
absorbed into your bloodstream and carried to your cells.
All year, we've been learning about living things: what they are, how they function, and how they've changed over time. All living things, including the squid you're dissecting today are made of cells. Inside those cells is DNA, the molecule that has the code for organisms traits. Each time a cell reproduces, it copies its DNA. Sometimes, it makes mistakes int the copying, which changes the code for the traits. This is called a mutation, and it creates diversity by coding for new traits. If the mutation does not harm an organism or if it gives an organism a trait that helps it survive, it will likely stay around or even become more common. This process of change over time is called evolution.
A long time ago in Earth's history, an organism lived that was the ancestor of both squid and humans. This is why we have many similarities. While you dissect the squid, notice the traits we have in common (Ex: We both have muscle tissue.) These are all traits we inherited from our common ancestor. Of course now, we are very different creatures. All the differences between squids and humans are the result of the collection of mutations and the differences in natural selection in different environments.
Before you dissect your squid, label the internal and external anatomy of your squid using the last 4 pages of this worksheet from USC
. Learn more about squid by watching the BrainPOP video about Giant Squid
, and the KQED video about Humboldt Squid
. Watch the video instructions
to see how to dissect your squid and identify the organs. Keep in mind that the squid in the video is preserved, and yours is fresh. Your squid's heart will be clear yellow, not red. The pen of your squid will be clear, not black. Also, if your squid is a female, the nidamental gland will be white, not yellow, but it will still cover the other internal organs. However, the ink sac will still be black, just like the preserved squid in the video.
When sound waves hit your ear drum, they make it vibrate. Try it out with a model of an ear drum. The plastic wrap represents your ear drum. The rice just makes the vibrations easier to see. Make a loud noise right next to the "ear drum" without touching it or blowing on it. What do you notice? Here is a video
in case you're having trouble.
Why Do You Have Ear Bones (Ossicles)?!
Sound is actually tiny vibrations moving through matter (solids, liquids, and gasses). That means that if there is no matter, there is no sound. This has some interesting effects. For example, in space, there is no matter, so there is no sound. You could be just feet away from a rocket, but you wouldn't be able to hear anything! Also, the more dense (packed together) matter is, the better the sound travels. Look at the diagrams below, and predict which substance (solid or gas) will transmit the most sound. Write your prediction in your science notebook.
- Make an ear gong to test your hypothesis!
- Wrap the strings around your index (pointer) fingers and tap the ear gong on the table WITHOUT putting your fingers in your ears. The sound is traveling through the air, a gas. How loud is the sound? (The louder it is, the more sound is traveling from the hanger to your ear drum.)
- Keep the strings wrapped around your fingers. Tap the ear gong on the table again, but this time, place your index fingers in your ears first. Now the sound is traveling through solids (the string and your fingers). How loud is the sound now?
So which type of matter transmitted sound better? How do you know? Write your answer in your science notebook.
Inside your ear are 3 tiny bones. Their job is to transmit sound from your ear drum to your inner ear where the actual nerve cells (cillia) are. Based on what you just learned about how sound travels, why do you think you have bones there instead of just air or fluid? Write your answer in your science notebook.
So how do your eyes work? The eye is a complex system. It is made up of many parts that all have to work together in order for you to see. Learn the parts of the eye and what they do by trying the virtual dissection
and studying the Quizlet set called "Eye Parts."
Light passes through the lens in your eye and makes an image on the back of your eye, the retina. The retina is made up of the nerve cells that sense light. The nerve cells send the signals to your brain. You can make a magnifying lens project a picture just like the lens in your eye does.
- Have a partner hold up a piece of plain, white paper facing a window or other source of bright light.
- Hold the magnifying lens close to the paper as if you are trying to let the window see the paper through the lens (see a picture). You should see a fuzzy image of the window appear on the paper.
- Move the lens closer to and farther away from the paper until you see the image come into focus. You should see the image of the window, but it should be upside down!
Just like the magnifying lens, the lens in your eye projects an upside-down image on your retina. It's your brain's job to turn the image right side up again!
You See with your Brain!
Sight is more than just taking a picture or a video with your eyes. Your brain has to figure out what that picture or video means. You don't actually see anything until your brain sees it! Not convinced? We can change what you see by sending confusing signals to your brain. To see how this works, let's watch some optical illusions from Brain Games
to learn more.
There are various ways we know what a certain part of the brain does. One way is to study what abilities people loose after they have an injury to a part of the brain. Another is to use fMRI scans to see which parts of the brain are most active when a person does a certain task.
Check out the sheep brain to see the different parts of a brain!
All vertebrates, including frogs and humans, evolved from a common ancestor, so we have a lot of traits in common. That is one of the main reasons we dissect frogs. Learning about the frog's internal anatomy can help us understand how our own organ systems work. Before our actual dissection, do the virtual dissection from MacGraw Hill
. While you dissect, answer the questions on your virtual dissection worksheet
. Use the worksheet to answer the questions on the "Virtual Frog Dissection" QuizStar.
Students are often surprised by the way the leopard frog's tongue looks. They generally think that they have damaged it because it is not connected at the back of the throat like ours is. Take a look at this slow motion video
to see how it works!
Students are often surprised by the way the leopard frog's tongue looks They generally think that they have damaged it somehow, but it's just different than our. Take a look at this slow motion video to see how it works.