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Sci 7- Unit 2- Topic 1-2-3
Transcript of Sci 7- Unit 2- Topic 1-2-3
Plants Topic 2:
Structure and Adaptation Topic 3:
and Breeding Plants in the Environment fibre: is the tissue of plants from the stem, leaves, seeds or roots. As a critical part of the ecosystem;
Plants provide oxygen.
Plants are able to use carbon dioxide.
Plants are start most food webs.
Plants also provide shelter for animals.
Plants clean and filter water.
Plants help prevent soil erosion. Plants for Food Nearly 75% of the the world's food supply is based on seven major crops:
sorghum From Plant to
Final Product (p. 93) Cocoa
Sugar Chocolate is made from the fruit of the cocoa tree 78% of vegetable oil production is from canola contains iodine and is used in soup broths and sushi half of the world's sugar comes from sugar beets, located in the sugar beets' roots Plants for Fibre Plants provide fibres for clothing, paper and shelter.
The aboriginal people from the west coast wove cloth from the bark of the western red cedar tree.
Much of our clothing today comes from synthetic (manufactured) material, such as polyester and nylon.
Natural fibres also provide resources for cloth: 3 examples: Cotton Hemp Flax Plants for Medicine Plant medicines include:
tea (made from ginger root) - is used to soothe an upset stomach
white willow bark - is used to ease pain
opium poppy's seed pod - thick milky fluid provides a powerful pain medication - morphine
codeine is also found in the poppy - it is used in cough medicines
quinine - which comes from the cinchona tree - is used to prevent malaria. Plants for Transportation
and Construction Rubber is one of the most important plant products that people use. Canoes were carved from trees by Aboriginal people. Plants for Fuel Wood or coal (which is a fossil fuel) are used to heat homes. Stop and think: What are all the parts of a plant? Can you label and name them all? What do you think they are? What would you call them? Copy this picture in your notes and label all the parts of the plant IN PENCIL!
Plants have particular habitats, each with its own set of environmental characteristics, including light, temperature water and soil conditions. The structure of a plant helps it to adapt to these conditions. There is much more to a plant than what you are able to see above the surface of the soil. In fact, up to one third of the plant can be beneath the soil Roots perform several functions: they absorb water and minerals from the soil
they support and anchor the plant so it cannot be relocated easily
they store food to help the plant survive during times of scarcity ROOT CROPS Generally grow in a short period of time, usually survive when there is little moisture and can be stored for long periods of time Diffusion and
Osmosis (p. 107) Diffusion is the tendancy of particles in a gas or liquid to become evenly distributed by moving from areas of greater concentration to areas of lesser concentration. The particles continue to spread out until they are evenly distributed within the enclosed area Osmosis is a particular type of diffusion in which only some of the particles are allowed to pass through a barrier. This barrier is called a differentially permeable membrane. Osmosis is the diffusion of water through a differentially permeable membrane. Roots Other plants have fibrous roots, which is a shallow system of similar-sized roots that can quickly soak up moisture. These smaller roots are covered in root hairs. The smaller roots and root hairs absorb water and nutrients from the soil. The most prominent part of the root in many plants is the taproot, with many smaller roots coming out from it, like branches on a tree. what are some root crops? Here's what it would
look like as air particles... you know, like someone
spraying "AXE" in
the hallway... everything starts to spread out... this is called:
DIFFUSION!!! osmosis in real life Stems leaves One function of the stem is to transport water and nutrients between the roots and the Support
Another function of the stem is to support the leaves and to ensure that the leaves receive enough light. To achieve this most stems grow above the ground Food Storage The food produced in the leaves is stored in the stem - like potatoes, which have swollen underground stems called tubers Some plants store food as sugar as well - the sugar cane is a good example. Different Types of Stems p.109 The loss of water through evaporation is called transpiration. A pigment called chlorophyll makes the leaves green. The energy of the sun is trapped in the leaves and changed into a kind of chemical energy. Carbon dioxide and water are used by the leaves in the process called photosynthesis, to make sugar (ENERGY) and give off oxygen. Plants also need a bit of oxygen - at night when photosynthesis does not happen, respiration does. Respiration is when a plant release carbon dioxide and lets oxygen into their cells. Water enters and leaves the cells in the leaves through the guard cells. When they absorb water they swell, opening the stoma (which lets in carbon dioxide and lets out water vapor). Many of the foods we eat, garden plants, and crops are
the result of selective breeding Selective breeding means that people choose specific plants with particular characteristics and encourage these plants to reproduce. Each Variety of apple above
has a different taste and use. For Example
some are are baking apples,while others are
best when eaten raw. their ability to withstand certain environmental conditions (hardiness)
how much food they produce (yield)
their resistance to disease.
their appearance (sweetheart cherries) New Genes- Page 117 Canola was developed using selective breeding and originated from a plant called rapeseed. Canola was developed to produce seeds that created a good-tasting oil. Canola crops are now more resistant to diseases, drought and even certain chemicals. Scientists can change plants by going inside an individual plant cell and modify some of its material, by removing parts of the cell that control particular characteristics. This genetic material ( genes of the plant ) can then be combined with genetic material from another plant to create a new plant - having characteristics from both plants. This process (biotechnology) is called genetic modification, or genetic engineering. Genetic Modification/ Engineering Types of Plant
Reproduction There are two way in which plants reproduce: 1)Sexual reproduction involves the production of seeds and fruits from specialized cells of two plants
2)Asexual, or vegetative reproduction, occurs when a 'parent' plant grows new plants from its roots, stems, or leaves.
Traditional types of vegetative reproduction include:
fragmentation (buds and root systems) An Example of what Grafting Looks Like: Seed Plant Reproduction In vegetative(asexual) reproduction, plants produce new plants identical to themselves.
In sexual reprocution - reproduction using seeds - the new plants are slightly different from their parents. Asexual Reproduction Video Pollination The process of pollen travelling to the female egg Parts of a Flower
Turn to page 122 to read along with the parts of a flower Flowers
Flowers use color, scent, nectar to attact animals, so that the pollination process can begin. can occur by self-pollination or cross-pollination. Look on Page 124 and tell me the
difference between self pollination and
cross pollination! The bee spreads pollen over
more crops than any other
insect Artificial pollination can also be used to breed different varieties of plants for specific purposes (usually to produce a better yield, or one that is more resistant to environmental conditions - such as cold winters) It is not just exposure to cold temperatures that kills seeds, but prolonged exposure to cold temperatures. From Seed to Fruit
Once a plant is pollinated, a seed is formed.
Seed Parts include the living plant (embryo) and the food suppy (cotyledon).
The length of time a seed is able to stay alive varies according to the conditions it experiences.
The longest-lasting seed was frozen for over 10,000 years before it sprouted and even flowered (p.125). Fruit
A fruit is the growing ovary of the plant that swells and protects the developing seeds of a plant, until they are ripe Seed Dispersal
Dispersal is the transportation of seeds away from the parent plant.
It can happen in various ways (see pictures on p. 127), including:
waterways (rivers, streams, etc.)
fire Spreading and Harvesting Seeds in the Field
Farmers use machines to disperse seeds.
Once they have grown into the crop, they are harvested in two steps.
A swather cuts the plants and lays them in rows (the stubble - what is left of the plant after being cut - prevents the plant from touching the soil, so the seeds can ripen).
A combine then separates the grain from the rest of the plant. (The grain seeds are collected and the straw is baled, or spread evenly over the field). Germination
Is the development of a seed into a new plant UNIT 2-
AND FIBRE Plants are also bred for ... The seeds can then be dispersed by various methods and when they get covered they can eventually sprout and become new pine trees. Cones The cone is the part of the tree that has a series of woody scales, and come in various shapes and sizes. Both male and female cones are produced by cone-bearing trees. Female cones contain ovules (eggs) - the small bumps at the end of a scale in a cone. Pollen grains develop on the smaller male cone.
Wind carries the pollen grains to the female cones.
Although most of the pollen grains never reach the female cones, those that do get caught in the sticky fluid near the ovule. A pollen tube grows to the ovule and sperm is able to ferilize the egg.
The process of pollination is complete.
Female cones of pine trees matrure, open, and release their seeds during the fall or winter months.
(This whole process takes at least two years) Pollination around 500 million people depend on it fifth most important cereal crop grown in the world Are there any other plants that we use for healing? Lubricants are provided from coconut and castor bean oils read pages 94-95 and write down the three main plants and what they are used for. Topic 1 Review:
All Questions side note:
For this Unit- you will keep all you Topic Reviews together.
Either in the same note book, or continued on the pages that you hand in.
At the End of the Unit, all your reviews will be together and marked on completion. Read page 105 read pages
110-111 Topic 2 Review:
Questions 1-6 read page 115 read page 118 read pages 120-121 Topic 3 Review:
Questions 1-3 Topic 1-3 Wrap Up: