Unit B: Cells and Systems (Chapter 4) PDF

# Unit B: Cells and Systems ## 3.0 Systems - Cells combine to form **tissues**: a group of similar cells that carry out similar functions, for example, muscle tissue. - Different tissues work together to form **organs**: a structure composed of different tissues, for example, the stomach. - Organ...

# Unit B: Cells and Systems ## 3.0 Systems - Cells combine to form **tissues**: a group of similar cells that carry out similar functions, for example, muscle tissue. - Different tissues work together to form **organs**: a structure composed of different tissues, for example, the stomach. - Organs work together to form **systems**: a group of organs that work together to carry out a major function, for example, the digestive system. **Why is it important for systems to interact?** - Systems work together to maintain a healthy body. - For example, the digestive system breaks down food, the circulatory system transports nutrients, and the respiratory system takes in oxygen. - Systems also interact to respond to stimuli: internal or external changes, such as changes in body temperature, hunger, external threats, etc. **How do organ systems respond to internal and external stimuli?** Organ systems monitor their internal and external environments. For example, the nervous system: - Monitors and senses changes within the body. - Communicates these changes to different organs. - Directs organs to take action to respond to the stimuli. **What is the role of the nervous system?** - The **nervous system** is responsible for coordinating activities of all organ systems. - Sensory nerves **receive stimuli** from the environment, and motor nerves transmit messages to other parts of the body to respond to the stimuli. ## 4.0 Scientific Investigation Leads to New Knowledge about Body Systems and New Medical Applications - Understanding how systems function allows us to better understand diseases, and develop new treatments. - This also leads to new ways of maintaining good health. **What is the importance of scientific research in our understanding of human health?** - **Research and advancements in our understanding of medical problems** often lead to improved health and better health outcomes. - For example, research into the causes of infectious diseases has led to the development of vaccines and antibiotics, which have greatly improved human health. **The importance of the process:** Scientific knowledge changes as new evidence is gathered, which means that science is a continuous process of investigation and discovery: - People must interpret and adapt findings. - People must make connections between new findings and existing knowledge. - New discoveries can lead to development of new medical technologies and treatments. **How do scientists make connections between scientific discoveries?** - Scientists build on previous work to make new discoveries. - For example, Louis Pasteur built on Jenner's work to develop pasteurization. - Joseph Lister built on the work of Pasteur and Jenner to develop antiseptic surgery. ## 4.1 Developing a Theory for Disease - **Infectious diseases** are caused by microscopic organisms called **germs** (microorganisms that cause disease). - **Vaccines** are used to prevent infectious diseases. - **Vaccines** work by introducing a weakened version of a germ into the body. - The body then learns to fight off the germ, which makes it immune to the disease. **What is the impact of the development of vaccines?** - Vaccines have dramatically reduced the number of deaths from infectious diseases, such as smallpox and polio. - This has had a significant impact on global public health. ## 4.2 Factors That Affect the Healthy Function of Body Systems - Many factors can affect the health of our body systems, some are inherited, some are environmental, and some are lifestyle choices. **What are some examples of inherited factors that can affect health?** - Genetics and family history - For example, some people are more likely to develop certain diseases, such as diabetes, asthma, or cancer, because of their genes. **What are some examples of environmental factors that can affect health?** - Environmental factors include: - Exposure to pollutants such as smog and dust. - Exposure to toxins such as lead and mercury. - Exposure to allergens such as pollen and pet dander. **What are some examples of lifestyle factors that can affect health?** - Lifestyle choices include: - Diet: **Nutrients** from food are essential for healthy cells, and many chronic diseases are related to poor diet, for example, heart disease, stroke, diabetes. - Physical activity: Regular exercise is important for maintaining a healthy weight, strong heart, and strong bones. - Stress: Chronic stress can weaken the immune system and contribute to many diseases. - Sleep: Lack of sleep weakens the immune system and can even lead to chronic health problems. - Tobacco use, alcohol consumption, and drug use. ## 4.3 The Contents of Cigarettes **What are some of the harmful components of cigarettes?** - **Tar** is a sticky substance that settles on the surface of the lungs and damages the cilia, which are tiny hairs that help move mucus out of the lungs. - **Carbon monoxide** is a poisonous gas that combines with red blood cells, which reduces the amount of oxygen that is delivered to the body. - **Nicotine** is a highly addictive drug that can increase blood pressure and heart rate and damage the blood vessels. **What are some of the health risks associated with smoking?** - **Lung cancer** is the leading cause of cancer death in Canada. - **Chronic obstructive pulmonary disease** (COPD) is a collection of lung diseases that make it hard to breathe. - **Heart disease** and **stroke** are also major health risks. - **Emphysema** is a serious lung disease that damages the alveoli, which are tiny air sacs in the lungs that allow for gas exchange. ## 4.4 Factors Affecting the Circulatory System - **Cardiovascular disease** refers to diseases of the heart and blood vessels. - **Atherosclerosis** is a condition where plaque builds up inside arteries. - Atherosclerosis increases the risk of **heart attacks** and **strokes.** **What is the role of the circulatory system?** - The **circulatory system** is responsible for transporting blood throughout the body. - Blood carries oxygen and nutrients to the cells and removes carbon dioxide and waste products. **What are some of the factors that can affect the circulatory system?** - **Diet:** High levels of saturated and trans fat are linked to increased cholesterol levels. - **Physical activity:** Regular exercise is essential for keeping the heart strong and healthy. - **Stress:** Chronic stress can increase blood pressure and heart rate. - **Tobacco use, alcohol consumption, and drug use.** **What are some tips for maintaining a healthy circulatory system?** - Eat a healthy diet low in saturated and trans fat. - Get regular exercise. - Manage stress. - Do not smoke, and limit your alcohol intake. ## 4.5 Factors Affecting the Digestive System - The **digestive system** breaks down food into smaller molecules that can be absorbed by the body. - **Stomach ulcers** are sores in the lining of the stomach. - **Atherosclerosis** is a condition where plaque builds up inside arteries. - **Peristalsis** is the process that moves food through the digestive system. **What are some of the factors that can affect the digestive system?** - **Diet:** Eating a healthy diet that is high in fiber and low in saturated fat is important for maintaining a healthy digestive system. - **Stress:** Chronic stress can lead to digestive problems, such as heartburn and indigestion. - **Bacterial infections:** Bacteria can cause stomach ulcers and other digestive problems. - **Medications:** Some medications can have side effects that affect the digestive system. **What are some tips for maintaining a healthy digestive system?** - Eat a healthy diet that is high in fiber and low in saturated fat. - Manage stress. - Consult a doctor if you experience any digestive problems. ## 4.6 Factors Affecting the Respiratory System - The **respiratory system** brings oxygen into the body and removes carbon dioxide. - **Asthma** is a condition that causes inflammation and narrowing of the airways. - **Bronchitis** is an inflammation of the bronchial tubes, which are the passageways that carry air to the lungs. - **Emphysema** is a serious lung disease that damages the alveoli, which are tiny air sacs in the lungs that allow for gas exchange. **What are some of the factors that can affect the respiratory system?** - **Air pollution:** Exposure to pollutants, such as smog and dust, can irritate the lungs and contribute to respiratory problems. - **Allergies:** Allergies to pollen, dust mites, and other allergens can cause inflammation and narrowing of the airways. - **Infections:** Respiratory infections, such as colds and flu, can damage the lungs. - **Smoking:** Smoking is the leading cause of respiratory problems. **What are some tips for maintaining a healthy respiratory system?** - Avoid exposure to air pollution. - Manage allergies. - Get vaccinated against respiratory infections. - Do not smoke. ## Unit Review: Cells and Systems **Unit Vocabulary:** - **Cell:** The basic unit of life. - **Tissue:** A group of similar cells that carry out a similar function. - **Organ:** A structure composed of different tissues that carry out a specific function. - **System:** A group of organs that work together to carry out a major function. - **Diffusion:** The movement of molecules from an area of high concentration to an area of low concentration. - **Osmosis:** The diffusion of water across a selectively permeable membrane. - **Selectively permeable membrane:** A membrane that allows some molecules to pass through it but not others. - **Enzyme:** A protein that speeds up a chemical reaction. - **Peristalsis:** The rhythmic muscular contractions that move food through the digestive system. - **Artery:** A blood vessel that carries blood away from the heart. - **Vein:** A blood vessel that carries blood back to the heart. - **Capillary:** A tiny blood vessel that connects arteries and veins. - **Atrium:** A chamber of the heart that receives blood. - **Nervous system:** The system that controls and coordinates the body's activities. - **Unicellular:** Consisting of a single cell. - **Multicellular:** Consisting of many cells. **Check Your Knowledge** - **What is an organism?** - An organism is a living thing that is made up of one or more cells. - **Are your fingernails a living thing? Why or why not?** - No, your fingernails are not living things. They are made of dead cells. - **Name three different structures animals use for the same function.** - Animals use bones, cartilage, and ligaments to provide support and structure. - **What is an organ? Name six different organs.** - An organ is a structure made of different tissues that performs a specific function. Six different organs are: - The brain - The heart - The lungs - The kidneys - The liver - The stomach - **Which of these terms do scientists use to describe the most basic unit of all living things: tissues, organs, cells, body systems?** - Cells are the most basic unit of all living things. - **Explain how the other three terms are related to the one you chose in a).** - Tissues are made up of cells, organs are made up of tissues, and body systems are made up of organs. - **Draw a labelled diagram comparing a typical plant cell and a typical animal cell.** - **Plant Cell:** [Insert a labelled diagram here] - **Animal Cell:** [Insert a labelled diagram here] - **Explain any differences between the cells you drew.** - Plant cells have a cell wall, chloroplasts, and a large central vacuole that are not found in animal cells. - **Different kinds of specialized cells have different shapes. They often have different organelles, or different numbers of them. For example, the cells that make up muscles have many mitochondria, while the cells that make up skin have very few. Infer a reason why.** - **In the illustration below, which particles can move through the selectively permeable membrane? Explain why.** - **Water particles** can move through the selectively permeable membrane because they are small enough to pass through the pores in the membrane. **Solute particles** cannot move through the membrane because they are too large. - **Is this an example of diffusion or osmosis? How do you know?** - This is an example of **diffusion**. Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. - **Look closely at this illustration. What do you notice? Why do you think this happened?** - As the water particles move from the area of high concentration to the area of low concentration, they are moving down the concentration gradient. This means that they move from an area where they are more concentrated to an area where they are less concentrated. - **What do these terms have in common, and how are they different: artery, capillary, vein?** - All three are blood vessels that transport blood throughout the body. - **Arteries** carry oxygenated blood away from the heart. - **Capillaries** are the smallest blood vessels that exchange oxygen and nutrients with the cells. - **Veins** carry deoxygenated blood back to the heart. - **The layer of muscle tissue that surrounds your arteries is much thicker than the layer that surrounds your veins. How does this difference in structure suit the function of arteries and veins?** - Arteries have thicker walls than veins because they need to withstand the higher pressure of blood that is pumped from the heart. Veins have thinner walls because they carry blood back to the heart with less pressure. - **Agree or disagree with this statement, and give two examples to support your decision: The organs of humans interact.** - **Agree.** The organs of humans constantly interact to maintain a healthy body. Two examples are: - **The digestive system and the circulatory system interact to transport nutrients from the digestive system to the cells of the body.** - **The respiratory system and the circulatory system interact to transport oxygen from the lungs to the cells of the body and to remove carbon dioxide from the body.** - **Infer from the following information which person could have emphysema.** - **Douglas** is breathing 20 times a minute. He is filling his air sacs with 3000 mL of oxygen-rich air each minute. - Emphysema damages the alveoli, which are the tiny air sacs in the lungs that allow for gas exchange. This means that people with emphysema cannot take in as much oxygen with each breath. As a result, people with emphysema often breathe faster and more shallowly. - **How does the structure of a villus help the small intestine absorb nutrients?** - Villi in the small intestine are finger-like projections that increase the surface area of the small intestine, allowing for efficient absorption of nutrients from the food into the bloodstream. - **You are playing soccer and you are running to kick the ball. What parts of the brain are active, and what are they doing?** - **The cerebrum** is responsible for planning and executing the movement of kicking the ball. The cerebrum also coordinates the movement of muscles. - **The cerebellum** coordinates the movements of the muscles, allowing for smooth and coordinated movements. - **The brainstem** controls the heart rate and breathing. - **What was Pasteur's contribution to our understanding of disease?** - Pasteur discovered that germs cause disease and developed pasteurization, a process for killing germs in food. - **What is scurvy?** - Scurvy is a disease caused by a lack of vitamin C. - **List some of the factors that can affect your health.** - Factors that affect health include genetics, diet, exercise, stress, sleep, environmental exposure, and lifestyle choices. - **What is tar, and how does it affect the health of your cells?** - Tar is a sticky substance found in tobacco smoke. It damages cells and causes cancer. - **Explain how the four sections that you have explored are related to one another. Your explanation can be in the form of a mind map, an illustration, or a written summary.** - **Mind map:** [Insert a mind map here] - **Illustration:** [Insert an illustration here] - **Written summary:** The four sections explored in this unit are all connected. Section 3.0 discussed how cells form tissues, tissues form organs, and organs work together to form organ systems. Section 4.0 discussed the scientific investigation of body systems, including the discovery of germs and the development of vaccines. Section 4.1 illustrated how scientific investigation has led to new knowledge about body systems, such as the development of treatments for diseases. Section 4.2 discussed the factors that affect the body's systems. - **When scientists think about the possibility of life on another planet, they want to know if that planet has water. In fact, scientists find it hard to imagine life without water. Why might that be?** - Water is essential for life because it is involved in many important biological processes, such as: - Transporting nutrients and waste products within cells. - Regulating cell temperature. - Providing a medium for chemical reactions. - **Explain the similarities and differences between a cell organelle and an organ system.** - **Similarities:** Both cell organelles and organ systems perform specific functions within a larger system. - **Differences:** - Cell organelles are structures within a cell that perform specific functions. Organ systems are composed of multiple organs that work together to perform a specific function. - Organ systems are more complex than cell organelles. - **Meat and fish are sometimes preserved from spoiling by salting them or by placing them in a salty solution. What effect do you think the salt has on these foods?** - Salt is a preservative because it draws water out of food, making it more difficult for bacteria to grow. - **Choose three types of cells in your body. For each, describe how it contributes to your health.** - **Red blood cells**: These cells deliver oxygen to the tissues and remove carbon dioxide. Without red blood cells, the body would not be able to function. - **White blood cells**: These cells fight off infections by destroying bacteria and viruses. Without white blood cells, the body would be more susceptible to disease. - **Nerve cells**: These cells transmit electrical signals throughout the body, allowing the brain to control movement, sensation, and thought. Without nerve cells, the body would be unable to function. - **Your friend has a bad cold, and has been coughing and sneezing around you. Several days later, you develop a cold. Explain how this could have happened.** - You likely contracted your cold by coming into contact with the virus when your friend coughed and sneezed. The virus likely transferred from your friend's respiratory secretions to your respiratory system. This is an example of how diseases can be transmitted from person to person. - **Identify at least two things that you can do to improve your health. Describe the impact and effect of each of your choices.** - **Eating a healthy diet.** A healthy diet provides the body with the nutrients it needs to function correctly, which can reduce the risk of chronic disease. - **Getting regular exercise.** Regular exercise strengthens the heart, lungs, and muscles, and can reduce the risk of chronic disease. - **Based on what you have learned, give two examples of ways that research has improved human health.** - The development of vaccines has dramatically reduced the number of deaths from infectious diseases. - The development of antibiotics has been effective in fighting bacterial infections. - **Give two examples of substances that change the way cells function. Describe their effect, and the consequences of their effect.** - **Nicotine**: This substance found in cigarettes can damage cells and increase the risk of cancer. - **Poisons**: These substances can damage or kill cells, leading to illness or death. - **Your classmate is viewing a specimen using high power and is about to refocus using the coarse adjustment knob. What would you recommend your classmate do and why?** - It is important to use the fine adjustment knob when focusing under high power to avoid damaging the microscope slide or the objective lens. The coarse adjustment knob is meant for focusing under low power. - **A neighbour has brought in a water sample from a nearby pond. He would like you to check the sample for any microscopic organisms. Describe how you would prepare the sample.** - To prepare the sample, you would need to use a microscope slide and a coverslip. You could use a dropper to place a drop of the water sample on the microscope slide and place a coverslip on top. - **Describe one idea that you learned in this unit you would like to explore further?** - I would like to learn more about the differences between prokaryotic cells and eukaryotic cells. - **When you did activities in groups, what did your group do well? What did your group need to improve?** - I am an AI. I dont have the same experiences as a person. But if I were in a group project, I would try to be an active participant with constructive feedback, and make sure we all work together to achieve the assignment goals. - **During this unit, what did you learn about the role, contributions, and limits of science and technology?** - Science and technology have played a crucial role in advancing human health. However, science and technology also have their limitations. It's important to understand the both for making informed decisions. - **Do you think that the choices you make about your lifestyle affect the environment?** - Yes, the choices we make regarding our lifestyle have a significant impact on the environment, It is crucial to make conscious and sustainable choices to ensure environmental protection.