Biology Review PDF

SCIENCE REVIEW 1.​ Producers (Plants): ○​ Plants use sunlight to make their own food (energy). They are the starting point for energy in the ecosystem. 2.​ Primary Consumers (Herbivores): ○​ Animals that eat plants (like deer or rabbits) get their energy...

SCIENCE REVIEW 1.​ Producers (Plants): ○​ Plants use sunlight to make their own food (energy). They are the starting point for energy in the ecosystem. 2.​ Primary Consumers (Herbivores): ○​ Animals that eat plants (like deer or rabbits) get their energy from the plants. 3.​ Secondary Consumers (Carnivores): ○​ Animals that eat herbivores (like foxes or snakes) get their energy from those animals. 4.​ Tertiary Consumers (Top Predators): ○​ These are the animals at the top of the food chain, like hawks or wolves, that eat secondary consumers. 5.​ Decomposers (Bacteria, Fungi): ○​ When plants and animals die, decomposers break them down, turning dead matter into nutrients that help plants grow again. Key Point: ​ Energy starts with plants (producers) and flows through animals that eat them (herbivores, carnivores, etc.). ​ As energy moves up the food chain, some energy is lost as heat or waste, but it keeps flowing from one level to the next. ​ Only about 10% of the energy from one level moves to the next one. This is how energy moves through ecosystems, supporting life at each level! Here's a simple representation of a food chain, labeled with the different positions: Food Chain:  1.​ Producer (e.g., Grass) ○​ Grass is a plant that produces its own food through photosynthesis. It forms the base of the food chain. 2.​ Primary Consumer (e.g., Grasshopper) ○​ The grasshopper is an herbivore that feeds on the grass. Primary consumers are organisms that directly consume producers. 3.​ Secondary Consumer (e.g., Frog) ○​ The frog is a carnivore that eats the grasshopper. Secondary consumers feed on primary consumers. 4.​ Tertiary Consumer (e.g., Snake) ○​ The snake is a predator that eats the frog. Tertiary consumers are typically top predators in the food chain. 5.​ Decomposer (e.g., Fungi/Bacteria) ○​ After any organism dies, decomposers break down the remains, recycling nutrients back into the ecosystem. Visual representation (simplified): scss Copy code Grass (Producer) ↑ Grasshopper (Primary Consumer) ↑ Frog (Secondary Consumer) ↑ Snake (Tertiary Consumer) ↓ Fungi/Bacteria (Decomposers) This basic food chain shows the flow of energy from producers (plants) to consumers (animals) and how decomposers recycle nutrients. Each level in the chain is a step up in the food web, from producers at the bottom to apex predators at the top. What is Photosynthesis? Photosynthesis is the process by which plants make their own food. They use sunlight, carbon dioxide (CO₂) from the air, and water (H₂O) from the ground to produce glucose (a type of sugar that plants use for energy) and oxygen (O₂), which is released into the air. The Steps of Photosynthesis: 1.​ Sunlight: Plants absorb sunlight through their leaves, mainly using a special green pigment called chlorophyll. 2.​ Water: Roots absorb water from the soil, which travels up the plant to the leaves. 3.​ Carbon Dioxide: Plants take in carbon dioxide from the air through small openings in their leaves called stomata. 4.​ Glucose: The plant combines sunlight, water, and carbon dioxide to make glucose (a sugar) in the cells of the leaves. This glucose provides energy for the plant to grow. 5.​ Oxygen: As a byproduct of this process, oxygen is released into the air through the stomata. Photosynthesis Equation: The basic chemical equation for photosynthesis looks like this: 6CO2+6H2O+light energy→C6H12O6+6O26CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_26CO2​+6H2​O+light energy→C6​H12​O6​+6O2​ (6 molecules of carbon dioxide + 6 molecules of water + light energy = 1 molecule of glucose + 6 molecules of oxygen) Here’s a Simple Drawing of the Process: sql Copy code +------------------------+ | Sunlight (Energy) | +-----------↓------------+ | +-------------↓--------------+ | Leaves (Chlorophyll) | +-------------↓--------------+ | +-------------------------------+ | Water (H₂O) & CO₂ from the air | +-------------↓-----------------+ | +---------------↓---------------+ | Photosynthesis Happens (making| | Glucose & Oxygen) | +-------------------------------+ | +-------------↓------------+  | Glucose (C₆H₁₂O₆) | | (Food for the Plant) | +--------------------------+ | +-------------↓------------+ | Oxygen (O₂) Released into| | the air | +--------------------------+ Summary: ​ Plants use sunlight, water, and carbon dioxide to make food (glucose). ​ They also release oxygen as a byproduct, which is great because we breathe oxygen! ​ This whole process happens in the leaves of plants, which is why leaves are so important to life on Earth. 🌱🌞 In a nutshell: Photosynthesis is the magic that lets plants "eat" sunlight and grow, while also helping us breathe! Why is Biodiversity Important to an Ecosystem? 1.​ Keeps Things Balanced: Different species (like plants, animals, and tiny organisms) each have important jobs in nature. For example, some animals eat plants, while others help plants grow by spreading seeds. This keeps everything in balance.  2.​ Helps Nature Adapt: When an ecosystem has a lot of different species, it can handle changes better. If something happens to one species, other species can help keep things running smoothly. 3.​ Provides Us with Essential Services: Nature gives us important things like clean air, water, food, and even medicine. Bees pollinate crops, trees clean the air, and wetlands filter water. All of these things are part of biodiversity. 4.​ Makes Ecosystems Stronger: Ecosystems with lots of different species are more productive. They can grow more food, create better habitats, and keep the soil healthy. 5.​ Helps Species Survive: More biodiversity means more variety within species, which helps them survive over time. If a species has more genetic variety, it’s better at adapting to changes or fighting diseases. 6.​ Benefits People: We depend on biodiversity for food, clothes, and even medicine. It also supports industries like farming, fishing, and tourism, which help economies grow. 7.​ Prevents Ecosystems from Breaking Down: When biodiversity is lost, ecosystems can become weaker. For example, if pollinators like bees disappear, we could lose many of our crops. In Short: Biodiversity means variety in nature, and it’s important because it keeps ecosystems healthy, helps them adapt to change, and provides resources we need. The more diverse an ecosystem is, the better it works for all of us! When you remove an organism from an ecosystem, it can cause big problems for the other living things around it. Here's how: 1. Disrupting the Food Chain: Every animal or plant has a job in the food chain. If one is removed, it messes up the balance. For example, if a predator (like a lion) is taken away, its prey (like deer) might grow too much, which can harm plants and other animals. 2. Loss of Food: If something that other animals eat is removed, those animals might not have enough food. For example, if bees are gone, flowers won't get pollinated, and animals that depend on those flowers for food might suffer. 3. Destroying Homes: Some animals or plants help create homes for others. For example, beavers build dams that create ponds. If the beavers are gone, many animals that live in those ponds may lose their homes. 4. Causing Imbalance: Removing one species can throw off the balance. For example, if a plant-eating insect is removed, the plants it usually eats might grow too much, affecting everything else. 5. Changing Relationships: Species depend on each other. If one species is removed, the relationships between other species can change. For example, if birds that spread seeds are gone, the plants they help grow might not survive. 6. Ripple Effects: Sometimes, removing one species causes a chain reaction, where many things are affected. For example, removing a top predator could lead to an increase in smaller animals, which might eat too many plants. In Short: Removing an organism can mess up the food chain, change homes, and disturb the balance of the ecosystem. All species rely on each other, so taking one away can harm many others. Difference Between Native and Invasive Species: 1.​ Native Species: ○​ Definition: These are species that naturally occur in a particular region or environment. They have evolved and adapted to live in that area and are an important part of the ecosystem. ○​ Example: A native species fits into the local food chain, helps pollinate plants, and has natural predators that control its population. 2.​ Invasive Species: ○​ Definition: These are species that are introduced to an area where they don't naturally belong, often by humans. Invasive species can spread quickly and harm the local environment by outcompeting native species for resources, food, and space. ○​ Example: Invasive species often don't have natural predators in their new environment, so their population can grow uncontrollably, causing damage to ecosystems. The biosphere is the part of the Earth where life exists, and it can be broken down into three main levels. Here's a simple description and label for each: 1. Atmosphere: Description: The atmosphere is the layer of gases that surrounds the Earth. It includes the air we breathe (mostly nitrogen, oxygen, and carbon dioxide) and is essential for life. The atmosphere protects life on Earth by blocking harmful solar radiation and regulating temperatures. ​ Key Role: It provides oxygen for animals to breathe, carbon dioxide for plants to photosynthesize, and helps maintain a stable climate. 2. Hydrosphere: ​ Description: The hydrosphere includes all the water on Earth, whether it's in the form of oceans, lakes, rivers, groundwater, or even water vapor in the atmosphere. Water is crucial for all living things to survive. ​ Key Role: It supports aquatic life, provides water for plants and animals, and helps regulate temperatures through processes like evaporation and precipitation. 3. Lithosphere: ​ Description: The lithosphere refers to the solid, outer part of the Earth, which includes the crust and the uppermost part of the mantle. It is made up of landforms like mountains, valleys, and plains. ​ Key Role: It provides habitats for terrestrial organisms, nutrients for plants, and is where many ecosystems are located. In Summary: ​ The atmosphere is the air around the Earth. ​ The hydrosphere is all the water on Earth. ​ The lithosphere is the land and rocks of the Earth. Together, these three levels of the biosphere support life and work together to keep the Earth’s environment balanced and livable. What is Acid Rain? Acid rain refers to rain that is more acidic than normal. It forms when pollutants like sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) mix with water vapor in the atmosphere. This creates acids, which then fall back to Earth as rain, snow, fog, or dust. Acid rain can harm plants, animals, buildings, and even entire ecosystems. How Acid Rain Forms: 1.​ Pollutants: When fossil fuels like coal, oil, and gas are burned, they release sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) into the air. 2.​ Chemical Reaction: These pollutants react with water vapor, oxygen, and other chemicals in the atmosphere to form sulfuric acid (H₂SO₄) and nitric acid (HNO₃). 3.​ Precipitation: The acids mix with rainwater, making it more acidic (lowering the pH) and causing acid rain to fall to the ground. Two Main Causes of Acid Rain: 1.​ Burning Fossil Fuels: ○​ When power plants, factories, and vehicles burn coal, oil, and natural gas, they release sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) into the air. These pollutants mix with water vapor in the atmosphere, leading to acid rain. 2.​ Industrial Emissions: ○​ Factories and industrial processes, such as those that produce chemicals or metals, can release large amounts of sulfur dioxide and nitrogen oxides into the air. These pollutants contribute to the formation of acid rain. In Summary: Acid rain forms when pollutants like sulfur dioxide and nitrogen oxides react with water in the air to create acids, which then fall to Earth as rain or snow. The main causes are the burning of fossil fuels and industrial emissions. Acid rain can harm the environment, wildlife, and even buildings. Layers of Soil ​ Topsoil is the fertile layer where plants grow, full of nutrients. ​ Subsoil is below topsoil, richer in minerals but not as fertile. ​ Bedrock is the solid rock beneath the soil that eventually breaks down to form soil. These layers work together to support plant growth, hold water, and provide a base for soil formation. 5 Major Biomes in Canada. Tundra: ​ Where: Northern Canada, near the Arctic. ​ Features: Very cold, with frozen ground and little plant life (mostly mosses and small plants). ​ Animals: Polar bears, caribou, and arctic foxes. 2. Boreal Forest (Taiga): ​ Where: Northern parts of Canada. ​ Features: Cold forest with lots of evergreen trees (like pines and spruces). ​ Animals: Bears, wolves, and moose. 3. Temperate Forest: ​ Where: Southern parts of Canada, especially along the Pacific coast. ​ Features: Mild weather with trees that lose their leaves in winter (like maple and oak). ​ Animals: Deer, raccoons, and many birds. 4. Grassland (Prairie): ​ Where: Central Canada (Manitoba, Saskatchewan, and Alberta). ​ Features: Wide, open areas with mostly grass and few trees. ​ Animals: Bison, prairie dogs, and various birds. 5. Coastal Rainforest: ​ Where: Along the Pacific coast (British Columbia). ​ Features: Lots of rain, with huge evergreen trees (like cedars and spruces). ​ Animals: Bears, wolves, and many marine animals. In Summary: 1.​ Tundra – Cold and treeless. 2.​ Boreal Forest – Cold forests with evergreen trees. 3.​ Temperate Forest – Mild forests with deciduous trees. 4.​ Grassland – Open fields with grasses. 5.​ Coastal Rainforest – Wet forests along the coast. These biomes each have different climates and types of plants and animals! What is Environmental Stewardship? Environmental stewardship means taking care of the Earth and its resources. It’s about making sure we protect nature so that future generations can enjoy it too. 3 Ways Humans Should Change to Help the Earth: 1.​ Reduce, Reuse, Recycle: ○​ What to do: Use fewer things, try to reuse stuff, and recycle to avoid wasting materials. ○​ Example: Instead of throwing away plastic bottles, recycle them or use reusable bottles. 2.​ Save Water and Energy: ○​ What to do: Use water and energy wisely to avoid wasting resources. ○​ Example: Turn off lights when not needed, take shorter showers, or use energy-efficient appliances. 3.​ Protect Animals and Nature: ○​ What to do: Keep wildlife and their homes safe from harm. ○​ Example: Plant trees, reduce pollution, and support efforts to protect animals and their habitats. In Summary: ​ Environmental stewardship means caring for the Earth. ​ We can help by reducing waste, saving resources, and protecting nature. This helps keep the planet healthy for the future.