Sci. y2 bio.2 (Ecosystem processes)

• Plants and algae are producers.

  They use photosynthesis to make their own food.

  They use carbon dioxide and water to make glucose and oxygen using light energy.
• To remain healthy, plants need to absorb minerals from the soil.

  They are absorbed through the root hair cells and then travel around the plant in the Xylem tubes.
• Nitrates are used for healthy growth.

  Phosphates are used for healthy roots.

  Potassium is used for healthy leaves and flowers.

  Magnesium is used for making chlorophyll.
• Some species of bacteria use energy released by chemical reactions to make glucose.

  This process is known as chemosynthesis.
• Energy is released in mitochondrion inside your cells by the process of aerobic respiration.

  Glucose and oxygen react together to release energy.

  Carbon dioxide and water are produced as waste products.
• Anaerobic respiration is a type of respiration that does not use oxygen.

  Anaerobic respiration in humans causes energy to be released from glucose.

  Lactic acid is produced as a waste product, which can build up in muscles and cause cramps.
• If two organisms both depend on each other for something, this is called interdependence.

  In a food web if the producer population decreases the consumer population will decrease.

  Toxic chemicals can build up in organisms through a food chain.

  This is known as bioaccumulation.
• Photosynthesis is the process in which plants take in carbon dioxide and water together with sunlight to make glucose and oxygen.
• Photosynthesis mainly takes place in the chloroplasts in the leaf cells.

  Leafs and stems are green because they contain chlorophyll.

  Chlorophyll is used to absorb sunlight.
• Water diffuses into the root hair cells.

  Than it travels through the xylem tubes.

  Gases get in the plants trough tiny holes on the bottem surface of a leaf, which are called stomata.

  Gases like carbon dioxide diffuse in, and gases like oxygen and water vappour diffuse out.
• leaves are divided in 2 main parts.

  The palisade layer, which contains chloroplasts and this is where most photosynthesis happens.

  The spongy layer, which contains air spaces so carbon dioxide can diffuse in.
• If a plant doesn't have enough of a certain mineral, the plant will have a mineral deficiency.

  Different deficiency's have different symptomps.
• nitrate deficiency: poor growth, older leaves get yellow

  magnesium deficiency: leaves turn yellow

  phosporus deficiency: poor root growth, young leaves look purple

  potassium deficiency: yellow leaves and dead patches
• Fertiliser is a chemical that farmers add to their crops to replace missing minerals.
• Some bacteria use other chemical reactions to make glucose.

  This process is called chemosynthesis.
• Leaves have several adaptations for photosynthesis: Lots of chlorophyll, large surface area, thin, and they have veins
• Around 10 % of energy at on level of a food chain is transferred to the next level.

  The other 90% is lost as heat.
• Glucose is transported in your blood, it dissolves into the liquid part of your blood called plasma.
• When you breathe in your alveoli in your lungs fill up with air.

  From here oxygen diffuses into your blood, than it is carried around your body by red blood cells.

  Red blood cells contain haemoglobin, which pick up the oxygen.
• carbon dioxide diffuses out of your cells into your blood plasma.

  It is carried out, and than exhaled.
• Some microorganisms carry out a type of anaerobic respiration called fermentation.

  Just as anaerobic respiration, fermentation doesn't need oxygen.

  In this reaction carbon dioxide and ethanol are produced.
• Ethanal is used to make food.

  Bakers mix water, flour and yeast to make dough.

  Yeast ferments the carbohydrates in the flour into ethanol and carbon dioxide. The gas makes the dough rise.

  Eventually the ethanol evaporates and you have bread.
• A food chain is a diagram that shows what an organism eats.
• A food web is a set of linked food chains.
• A predator is an organism that consumes other animals, a prey is an organism that is eaten by other animals.
• A niche is the particular place or role that an organism has in its ecosystem.
• There are many different organisms that work together in a ecosystem.

  At the roots and litter microorganisms break down old leaves, releasing nutrients that the tree absorbs.

  At the trunk insects have shelter and food from the tree.

  And in the tree canopy many other organisms also live there.