Science Unit B Study Notes: Plants, Photosynthesis, and Reproduction | PDF

**[Unit B study notes ]** **[Chapter 1.1]** [Seed plants]- come in all shapes and sizes Plant structure [Roots:] absorb water and nutrients Anchor the plant in the Soil [Stems]: Support for leaves & reproductive structures [Flowers:] Contains both male and female reproductive parts...

**[Unit B study notes ]** **[Chapter 1.1]** [Seed plants]- come in all shapes and sizes Plant structure [Roots:] absorb water and nutrients Anchor the plant in the Soil [Stems]: Support for leaves & reproductive structures [Flowers:] Contains both male and female reproductive parts [Seeds]: Contain an embryo Contains food supply [Leaves:] Produces food for the plant Photosynthesis [Cones]: Structure that produces seeds that contain an embryo **[Chapter 1.2]** Root Systems-up to one-third of a plant can be hidden underground - They absorb minerals from the soil it anchors the plant to prevent erosion They store food and help the plant survive [Types of Root Systems] Taproot system- one single root, with numerous small roots coming out of it Penetrates deep in the soil for nutrients holds the plant up Fibrous root systems- made up of several similarly-sized roots quickly soak up excess moisture efficient in nutrient uptake [4 processes for water moving up from the roots ] Transpiration Capillary Action Diffusion Osmosis Water Movement -- Transpiration it\'s when plants sweat Water Movement - Capillary Action the liquid is attracted to the molecules of the solid. This makes the liquid move along the surface Water Movement -Diffusion Movement of particles from high concentration to low concentration until equilibrium is reached Water movement-Osmosis The diffusion of water through a semi-permeable membrane [Semi-permeable membrane]-- is a filter for particles [A Process to Make Food] Plants make their food by Photosynthesis Photosynthesis produces a type of sugar Photosynthesis occurs in the chloroplasts located on the leaves The chloroplasts capture the sun's energy and combine carbon dioxide and water to make sugar. [How Do Plants Move Substances in and Out of Plant Cells] The plant cell is surrounded by a membrane with tiny openings known as pores. The cell membrane acts as a filter, keeping some substances inside the cell while allowing other substances to move in and out of the cell by Diffusion [A Process to Exchange Gases: Photosynthesis] Gas exchange is the process of these gases entering and leaving the plant. In the process of photosynthesis - In the process of cellular respiration - **[Chapter 1.3 ]** [The stages of the life cycle of a plant ] 1\. The Seed Stage A Seed has 3 main parts: an embryo, stored food, and a seed coat. The embryo uses the stored food to survive until the plant photosynthesizes and produces its food. 2\. The Seedling Stage Plants in this stage grow quickly and produce new leaves, roots, and stems. 3\. Adult Stage it produces reproductive structures. **Reproduction of seed plants**  Pollination **Pollinators:** plants release pollen in the air, where it is carried by the wind. many flowering plants rely on pollinators; -organisms that carry pollen from one flower to the other. Flowers produce nectar -Sweet & Sugary -Lures pollinators -Pollen gets attached to pollinators while they eat the nectar Reproduction Without Seeds This is Referred to as Vegetative Reproduction. The offspring produced are identical to the parent plant. **Types of Vegetative Reproduction:** 1\. Runners (long stems on the surface) 2\. Rhizomes (stems underground) 3\. Suckers (new plant from roots) Technology to Reproduce Plants - Cutting small pieces of a plant that has part of the stem and a few leaves. Grafting Attaching a part of one plant onto another plant. **[Chapter 1.4 ]** Plants are adapted to their Environments **Cacti Plants** Dry Environments Thick stems Water storage Spines for protection from predators **Grasses & Sunflower** Have narrow thin leaves Deep roots for droughts Bright petals to attract pollinators **Spruce Trees** Needle-like leaves with thick resin coating Stops plant from drying out **Fibrous and Taproots** Fibrous roots gather water at the upper layers of the soil. Taproots get water deep underground that other plants can't reach **Wild mustard plants** Adapted to short growing seasons Produce seeds in less than two months **[Chapter 1.5]** Plants have specific needs plants have requirements to grow and reproduce Plants Need Different Amounts of Light Light for photosynthesis and food. Some need lots of light while others don't. Plant Needs Different Amounts of Water Plants need water to survive Too much water can harm the plant Plant Needs Different Nutrients plants need nutrients for growth Nutrients: substances that provide energy to grow Nutrients: Nitrogen, Phosphorus, Potassium, Calcium, Magnesium Not enough nutrients = grow slowly. Plants Need Different Amounts of Space All plants need space to grow Some more than others More space=more sunlight=more nutrients **[Chapter 2.1]** Plants Provide Oxygen Humans produce a lot of carbon dioxide (factories, engines in cars, breathing out) We need oxygen to live! Plants use up carbon dioxide (via photosynthesis) Plants release oxygen Plants Provide Food Plants make their food from photosynthesis In turn, the plant becomes food for many organisms and those animals are eaten by something else Plants provide shelter Plants protect other organisms from weather and predators Plants build and protect soil Dead plants build up to build soil. Plant root holds the soil to prevent erosion (erosion: moves the soil from one place to another by wind, water, and animals) Plants connect organisms Plants (producers) allow the connection of the food web/chain. A grasshopper eats corn, a frog eats the grasshopper, and so on **[Chapter 2.2]** Humans have been using plants for many uses First Nations communities throughout centuries have been using plants for: Medicine Food Fibre Ex. A paint brush was used to treat rheumatism and the flower is sweet and can be eaten Ex. Tea is made from white spruce and hemlock to cure scurvy (vitamin C deficiency). Main Purposes of Plants 1\. Food 2\. Fibre 3\. Medicine 4\. Fuel 5\. Construction & Transportation 1\. Plants for Food Fruits and Veggies 75% of the world's food supply is based on these 5 main crops: -Wheat -Rice -corn -Barley -Cassava -Livestock 2\. Plants for Fibre The material that is extracted from plants and woven to make clothing Common Fabrics we use: -Cotton -Hemp -Flax -Silk Plants for Medicine More than 7000 medicines are made from plants The original medicine Ex. Ginger, garlic, and ginseng when you're sick! Plants for Transportation & Construction Rubber is one of the most important plant products we use Plants for Fuel Fossil fuels that we use as a fuel source are not an unlimited resource (non-renewable; it takes millions of years to make) Solution: use Ethanol & Methanol - - **[Chapter 2.3 ]** What are Living Resources? Living resources are living things that can be used for human needs Trees, animals, bugs etc first Nations and Alberta's Resources The first people to use living resources in Alberta are the First Nations, Metis, and Inuit. Food and Fibre by hunting and gathering Medicine from plants Horses for travelling Bows for hunting Nothing is gone to waste Subsistence living: Only taking enough from the natural environment to live European Settlers and Living Resources When the settlers came, they used significantly more of the land for themselves and others (commercially for trade) Used significantly more wood for building and fuel. Brought new technology to harvest With greater use and new technology to harvest, there was the need to manage living resources. Why do we need to manage living resources? The increase in the world's population increases the demand for natural resources We can't just destroy forests to provide for our needs because it is non-sustainable: Resources are being used more faster than they are being made -- we won't have any resources in the future! How do we become sustainable? By managing resources! Agencies manage forest resources -Regulations - What can be harvested - What species is okay to harvest - How they are removed - How they are restored and replaced - **[Chapter 3.1]** What do you think of when you hear the word "Soil"? Soil varies depending on where you are in the world -- not all soil is made the same Grain Sizes Soil isn't just dirt. They contain tiny particles with spaces that contain either water or air Soil Contains Mineral Particles Mineral Particles- Made from rocks that have been broken down (non-living) Spaces where water can run through quickly Soil Contains Organic Particles Organic particles are made out of dead plants and animals (fully decomposed). Partly decomposed organic matter is called humus -- which contains nutrients and absorbs water. Organic and inorganic soils Organic soils- composed mainly of decayed plant and animal matter Inorganic soils- composed mainly of minerals 3 Types of Soil 1\. Sandy Soil 2\. Clay Soil 3\. Loam Soil Sandy Soil Runs through your fingers Light brown Mostly made out of minerals Loamy Soil Crumbly-like moist cake Dark brown/black Mix of organic and mineral particles Plenty of nutrients for plants (good for growing!) Clay Soil Slippery/moist/oily Forms a tight ball when squeezed Contains lots of mineral particles and some humus particles Holds water well Fine Texture (small particles) **[Chapter 3.2]** Why is it important to manage Soil? Soil is an important natural resource. We use soil to grow plants for food and fiber Without soil -- no benefits from plants What do humans do to our soil? Use fertilizers Irrigation Clearing the Land Plowing Crop rotation Fertilizer Use Fertilizers provide nutrients to the soil for plant growth Organic Fertilizers (animal & plant waste) & Chemical Fertilizers (ex. Potash) Too much: harms the plant and extra nutrients go to runoff and pollute rivers, streams, or lakes Irrigation -- Watering plants Used to provide water to plants that live in dry areas with no rainfall Provide a precise amount of water when farming Too much: can drown the plant (no air for plants) & makes the soil is too salty (evaporation of water) Clearing the Land Farming and foresting need a lot of areas to obtain resources If not careful, no plant to hold soil (increase in erosion), water compacts soil (no plant can grow on this), and no shade so the water evaporates quicker Plowing Changes Soil Process of cutting into the soil and turning the top layer over Plowing damages the soil breaks up the soil, making the soil more compact and make it waterlogged Crop Rotation Farmers rotate what they grow on a certain field every year Growing the same crop would render the soil without nutrients for plant growth Rotating crops gives the soil time to regenerate important nutrients **[Chapter 4.1]** What is Yield? Yield -- the amount of useful plant parts per plant. Greenhouses Artificial Environment Made out of glass or transparent material to allow sunlight to enter Used to control climatic conditions suitable for plant growth: right temperature, light, and nutrients Hydroponics Artificial soil environment Plants are grown without soil Roots of plants are buried in gravel or coarse sand Plants get their nutrients from nutrient-rich water. **[Chapter 4.2 ]** We grow different kinds of Plants Most plants are developed by growers and scientists to meet specific demands. Ex. Farmers in Alberta developed a carrot for the short growing season in Alberta. Species, Varieties & Traits A species is a group of organisms with similar traits that can reproduce with each other. A variety is a subset of a species. A variety has specific characteristics or traits that distinguish it from other varieties Why the need to grow varieties of plants? To provide us with plants with traits that we need or want Ex. Grow plants that can grow in colder climates, tolerate salty soil, or fight diseases or attack by insects. Varieties are developed by Selective Breeding Growers and farmers use selective breeding to develop new varieties of plants Selective Breeding -- the process of selecting plants with specific traits and reproducing them Selective breeding has been used since people first started farming Genetic Engineering Genetic Engineering is when a single gene from one plant is added to another plant's cells. Gene -- a tiny piece of genetic material found in a cell's (DNA) Each gene in a cell is responsible for the inheritance of certain traits and characteristics This genetic material can come from other plants or a different living thing entirely. New Varieties Can Cause New Problems New varieties of plants bring with them new problems They may require more fertilizer or special treatments which can be costly Some new varieties may be more attractive to pests requiring more pesticides. Ex. Canola (oilseed crop) was genetically engineered to protect it against insect damage and herbicides. **[Chapter 4.3]** Weeds & Pests Plants that interfere with the growth of commercial crops are called weeds Animals that eat or affect the growth of commercial crops are called pests Weeds and pests have a role in the environment However, farmers must produce crops, so they need controls to maximize their crop yield. The need to control pests Mountain pine beetles- have been destroying the Canadian Boreal Forests and are considered a pes Controlling Weeds -- Herbicides Farmers use herbicides to kill weeds and selected plants Herbicides are chemicals that kill plants Issues with herbicides Stops the food chain; other animals that depend on this food sources will die. Build-up of herbicide in the soil; soil becomes less fertile for certain plants Washed up into water systems; poisonous for water environment Weeds become resistant to it if used for a long time Controlling Insects -- Pesticides Substances that kill insects are called pesticides Issues: Kill helpful insects (pollinators) Insects become resistant Can contaminate food source Biological Control Using natural predators to control pests Natural way of controlling pests Issues: It takes a while to work - Does not take out all of the pests \- Not useful for managing a large outbreak of pests **[Chapter 4.4]** Environmental Management It is balancing the needs of humans with the needs of the environment When managing the environment, we need to study both intended consequences and unintended consequences. Ex. Animal Bridges. What are the intended consequences and unintended consequences? Monoculture -- Farm Management A process of dedicating a field to planting just one variety of plant Intended Consequences: Cut down on cost and fertilizer overuse Easy Harvest Unintended Consequences: Give pests a huge supply of their favorite food; pest population can explode Reduces biodiversity (only one kind of habitat available) Economic & Social Effects of Sustainable Practices Let's remember crop rotation\... What are the benefits of a farmer rotating their crops? - - -