Unit B Lesson B1 Living Things
Completion requirements
Lesson B1: What is a Living Thing?
Video Lesson
What characteristics are shared by all living things? How do you know if something is alive or not? Watch this video to learn more.
Lesson B1: What is a Living Thing?
Figure B.1.1.1 – Viruses are too tiny to see with the naked eye.
Figure B.1.1.2 – Viruses often cause illnesses.
Figure B.1.1.3 – Viruses can spread quickly in a variety of ways.
Reading and Materials for This Lesson
Science in Action 8
Reading: Pages 85–88
Materials:
Virus template, cardstock paper, scissors, tape, drinking straw, ruler, pipe cleaners (3).
Viruses: Alive or Not?
Most people have been sick with a cold. Colds quickly spread between people, creating sore throats, runny noses, and coughing. There is no medicine to cure a cold. It takes rest and time for the body’s immune system to fight the sickness.
Colds, and many other diseases, are caused by viruses. Viruses are tiny and reproduce quickly like other microorganisms. However, most scientists don’t consider viruses to be living things.
Viruses are not cells. On their own, they are dormant and don’t cause harm. But once viruses are in contact with a living cell, they invade and take over the cell. Viruses use nutrients in the living cell to reproduce and make more viruses. These new viruses escape the first cell and keep reproducing in other cells of the organism.
The immune system in the human body recognizes many viruses as invaders and destroys them. This is how the body heals from most viral infections. A few types of viruses, like the human immunodeficiency virus (HIV) and ebola, attack immune system cells. These are deadly viruses because they prevent the immune system from fighting them.
Most people have been sick with a cold. Colds quickly spread between people, creating sore throats, runny noses, and coughing. There is no medicine to cure a cold. It takes rest and time for the body’s immune system to fight the sickness.
Colds, and many other diseases, are caused by viruses. Viruses are tiny and reproduce quickly like other microorganisms. However, most scientists don’t consider viruses to be living things.
Viruses are not cells. On their own, they are dormant and don’t cause harm. But once viruses are in contact with a living cell, they invade and take over the cell. Viruses use nutrients in the living cell to reproduce and make more viruses. These new viruses escape the first cell and keep reproducing in other cells of the organism.
The immune system in the human body recognizes many viruses as invaders and destroys them. This is how the body heals from most viral infections. A few types of viruses, like the human immunodeficiency virus (HIV) and ebola, attack immune system cells. These are deadly viruses because they prevent the immune system from fighting them.
Watch More
We're Going Viral!
Watch this video to learn more about how viruses reproduce.
Watch this video to learn more about how viruses reproduce.
Scientists are still debating whether or not viruses are alive. Watch this video to learn about a recent scientific development that supports viruses being alive.
This animation explains how viruses invade and reproduce inside human body cells.
Connections
Figure B.1.1.4 – Viruses have interesting geometric shapes.
Figure B.1.1.5 – Bacteriophage viruses invade bacterial cells.
Figure B.1.1.6 – Some viruses are rod-shaped or spherical.
>> Geometric Viruses
Viruses have different three-dimensional geometric shapes. Some viruses, like the flu virus, have a round spherical shape. Other viruses, like the rabies virus, have a cylindrical rod shape.
Many viruses have a polyhedral shape. Poly means “many” and hedron means “base”, so a polyhedron is a three-dimensional geometric solid that has many bases, or sides. Icosahedral viruses have 20 triangular faces, that form a sphere-like shape. The cold virus is an example of an icosahedral virus.
Bacteriophages are viruses that attack and invade bacterial cells. Bacteriophages have a complex shape. They look like a polyhedron with legs. Their main structure has the geometry of an elongated hexagonal bipyramid.
Try It!
Build Virus Models
Viruses come in several different geometric shapes. Try this activity to build two virus models.
Materials:
Viruses come in several different geometric shapes. Try this activity to build two virus models.
Materials:
- Virus template (link here)
- Cardstock paper or heavy printer paper
- Scissors (large and small)
- Tape and glue
- Drinking straw (optional)
- Ruler
- Letter opener or ballpoint pen
- Pipe cleaners
Safety Warning
Take care with scissors; don't cut yourself or anyone else!
Instructions:
- Print both virus templates on
cardstock paper (if you don’t have cardstock paper, you can use heavy printer paper, but your virus model might not stand up quite as well.)
- Cut out the shape templates along the outer solid lines.
- On both shapes, carefully fold inwards along the inner dotted lines to form the three-dimensional shape and its connecting flaps.
- For the icosahedral papovavirus model, use tape or glue to hold the flaps onto the rest of the shape as you continue to fold inward.
- For the bacteriophage virus model, assemble the paper straw by folding in along the lines and using tape to hold it together. You may use a normal straw if you wish.
- The other two shapes are each half of the ‘head’ of the bacteriophage. Cut out both shapes and fold along the dotted lines, using tape to hold the 3D shape together as you build.
- Use tape to connect the two halves together to form the full prism.
- Attach the straw to the bottom of the bacteriophage polyhedron prism.
- Cut the three pipe cleaners in half. Fold the six pieces of pipe cleaner in half to make legs.
- Tape the six legs around the end of the straw with equal spacing.
- Watch this video to see this experiment and its results:
Figure B.1.1.7 – A roundworm is a parasite that lives in animal intestines.
Figure B.1.1.8 – Tapeworms can grow up to 10 metres long!
Figure B.1.1.9 – Botfly larvae burrow into skin.
Parasites
Parasites are organisms that live on or inside of another host organism. Parasites obtain nutrients by stealing them from the host organism. Parasites depend on other organisms for energy and reproduction, but they are still considered to be alive because they are made of cells.
Many animals act as unwilling hosts for parasites. For example, cats and dogs often get roundworms. The worms live in the animal’s intestines, where they eat nutrients before the nutrients are absorbed into the animal’s body. People often have to take their pets to the veterinarian to have worm parasites removed, which is called de-worming.
Humans can be hosts for parasite worms too. For example, tapeworms sometimes grow inside human intestines. People can host a tapeworm, but experience no symptoms. Tapeworms can grow to be 10 metres long inside the body! People get tapeworms when they eat food or drink water contaminated with feces. You can prevent getting a tapeworm by washing your hands after using the washroom, by cooking meat properly, and by not drinking untreated water.
Parasites are organisms that live on or inside of another host organism. Parasites obtain nutrients by stealing them from the host organism. Parasites depend on other organisms for energy and reproduction, but they are still considered to be alive because they are made of cells.
Many animals act as unwilling hosts for parasites. For example, cats and dogs often get roundworms. The worms live in the animal’s intestines, where they eat nutrients before the nutrients are absorbed into the animal’s body. People often have to take their pets to the veterinarian to have worm parasites removed, which is called de-worming.
Humans can be hosts for parasite worms too. For example, tapeworms sometimes grow inside human intestines. People can host a tapeworm, but experience no symptoms. Tapeworms can grow to be 10 metres long inside the body! People get tapeworms when they eat food or drink water contaminated with feces. You can prevent getting a tapeworm by washing your hands after using the washroom, by cooking meat properly, and by not drinking untreated water.
Watch More
Parasites are Amazing... and Gross!
What are some other parasites that the human body hosts? Watch this video to learn more.
What are some other parasites that the human body hosts? Watch this video to learn more.
Watch this video to learn how parasites can influence the behaviour of organisms.
This video shows live tapeworms inside a person’s intestines.
The botfly lays eggs on the skin of organisms like cows. Sometimes botflies lay eggs on human skin. Hatched botfly larvae then feed off the human. Watch this video to see a botfly larvae parasite being removed from a woman’s head.
WARNING: Things get pretty gross at the end of this video. If you're squeamish you might want to skip this one.
Figure B.1.1.10 – Spawning salmon leave eggs in a river.
Figure B.1.1.11 – Salmon jump up waterfalls during the salmon run.
Figure B.1.1.12 – Salmon farming can be harmful to wild salmon.
Spawning Salmon
Salmon fish are an important food source for both humans and large mammals in the northern hemisphere. Wild salmon live in both the Atlantic and Pacific Oceans.
Salmon reproduce in a very interesting way. Baby salmon hatch from eggs in freshwater rivers. They swim down rivers to the ocean, where they spend most of their lives. When salmon are ready to reproduce, they swim back up river to the exact place where they were born. This is called a salmon run. It takes a lot of effort for salmon to swim upstream against river currents. Salmon can even jump up waterfalls!
When salmon reach their birthplace, they spawn, or reproduce. Salmon leave fertilized eggs in the river. Once salmon are done spawning, they die.
Salmon are very important to First Nations people, especially in British Columbia and the Yukon. Traditionally during the salmon run, First Nations caught salmon with nets or wood barriers. It was a very sustainable process. When First Nations communities caught enough fish to meet their needs, they removed the barriers in the river so that other salmon could keep swimming to their spawning grounds. This ensured that new salmon would be born for the future.
Some First Nations communities still depend on salmon for food, but this traditional way of life is threatened. Modern overfishing methods have reduced wild salmon stocks and disrupted the salmon run. Coastal First Nations communities are concerned about proposed oil pipelines leading to the coast, because potential oil spills could kill and poison salmon. Salmon farming is another controversial practice, because it causes diseases that can spread to wild salmon.
Salmon fish are an important food source for both humans and large mammals in the northern hemisphere. Wild salmon live in both the Atlantic and Pacific Oceans.
Salmon reproduce in a very interesting way. Baby salmon hatch from eggs in freshwater rivers. They swim down rivers to the ocean, where they spend most of their lives. When salmon are ready to reproduce, they swim back up river to the exact place where they were born. This is called a salmon run. It takes a lot of effort for salmon to swim upstream against river currents. Salmon can even jump up waterfalls!
When salmon reach their birthplace, they spawn, or reproduce. Salmon leave fertilized eggs in the river. Once salmon are done spawning, they die.
Salmon are very important to First Nations people, especially in British Columbia and the Yukon. Traditionally during the salmon run, First Nations caught salmon with nets or wood barriers. It was a very sustainable process. When First Nations communities caught enough fish to meet their needs, they removed the barriers in the river so that other salmon could keep swimming to their spawning grounds. This ensured that new salmon would be born for the future.
Some First Nations communities still depend on salmon for food, but this traditional way of life is threatened. Modern overfishing methods have reduced wild salmon stocks and disrupted the salmon run. Coastal First Nations communities are concerned about proposed oil pipelines leading to the coast, because potential oil spills could kill and poison salmon. Salmon farming is another controversial practice, because it causes diseases that can spread to wild salmon.
Watch More
Salmon Run
Watch this video to learn more about salmon spawning.
Watch this video to learn more about salmon spawning.
In this video, a First Nations elder speaks about the salmon run.
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
Unit B Lesson 1 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps – if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
- DOWNLOAD the self-check quiz by clicking here
.
- ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
- COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
-
REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
- SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
- CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Be a Self-Check
Superhero!
Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.
Lumber wood is a dead organism. It is made from trees that used to be alive. Even though lumber is made from cells, it is not alive, because it no longer has the characteristics of a living thing. Wood can’t grow anymore. It does not use energy
and nutrients, it does not respond to stimuli, it does not reproduce, and it does not adapt to its environment.
Endangered species mainly struggle with reproduction. There are many reasons why a species could struggle to reproduce. Regardless, if a species stops reproducing, it will become extinct.
Endangered species can struggle with obtaining energy and nutrients, which is also related to reproduction. If an organism cannot get enough energy, it will die, which stops its ability to reproduce.
Endangered species can struggle with obtaining energy and nutrients, which is also related to reproduction. If an organism cannot get enough energy, it will die, which stops its ability to reproduce.
When a plant moves, it is showing a response to stimuli. The plant is moving in response to the stimulus of light. The plant is moving to maximize the exposure of its cells to energy from the Sun. The plant will use this energy from the Sun
to make food, so it can grow and reproduce. The ability of a plant to move towards light is an adaptation that helps it survive.
Cats have many adaptations. They have sharp retractable claws that allow them to jump up higher to stalk prey or for protection from predators. Their sharp claws also allow cats to hold their prey. Cats have very sensitive whiskers that detect
changes in their environment. Cats have good eyesight to help them hunt prey at night.
Some animals eat plants. Plants get their energy from the Sun, so the energy that plant-eaters obtain from plants first came from the Sun.
Some animals eat meat. However, if you trace the food chain below meat-eaters, eventually you will find an animal that eats a plant-eater. As explained above, plant-eaters originally get their energy from the Sun, which means that meat-eaters also get their energy from the Sun.
Some animals eat meat. However, if you trace the food chain below meat-eaters, eventually you will find an animal that eats a plant-eater. As explained above, plant-eaters originally get their energy from the Sun, which means that meat-eaters also get their energy from the Sun.