science chapter 12 interactions within ecosystems

• how do our actions impact the environment

  • earth has limited resources
  • will continue to deplete at a faster rate than it should be
  • our actions can impact the environment and ecosystem
  • it also affect the survival of other living ecosystem
• what are the human activities that will impact the environment

  1. wasting food
  2. using more electricity
  3. using more water
  4. creating more waste
• 1. wasting food

  • wasting food = wasting Earth's limited resources
  • growing crops and livestock (food sources) require many resources as well
• examples of resources

  • space
  • facilities
  • energy
  • water
• 2. using more electricity

  • electricity is generated by burning fossil fuels through energy conversions
  • Singapore uses natural gases
• How does using more electricity impact the environment

  1. using more electricity
  2. more fossil fuels will be used
  3. more carbon dioxide is produced and released
  4. increasing the greenhouse gases
  5. global warming
• 3. using more water

  • less than 1% of water is fresh
  • water needs to be treated before it can be used = needs energy and money
  • using more water = using more energy = depleting the limited resources
• 4. creating more wastes

  • many human activities generate wastes
  • excessive waste causes pollution of air, water and land, health problems, and discharge of chemicals
• how can we contribute to the effort of conversing the environment?

  1. reducing the use of fossil fuels
  2. reducing consumption
  3. introducing environmentally friendly products
  4. reforestation
• actions to reduce the use of fossil fuels

  1. taking public transport/walking instead of driving a car (uses fossil fuels)
  2. using energy-efficient electrical appliances
  3. reducing use of air-conditioner
  4. reducing energy consumption
• actions to reduce consumption

  1. minimising the use of paper
  2. reducing the need for raw materials (wood etc.)
  3. reusing and recycling items = reduce the need for extracting more metals from earth
• actions to introduce environmentally friendly products

  1. Bring your own Bag - encourages people to use less plastic products
  2. separation of recycling items - differentiate recyclable wastes from non-recycable wastes for recycable efforts
• actions that that helps to reforest

  • reforestation can replace some of the plants lost due to deforestation

  1. growing in soil = prevent land erosion
  2. photosynthesis = remove carbon dioxide
  3. reduce impact on climate change
  4. provide food supply for most organisms
• what is a habitat?


  it is a place where an organism lives (E.g. urban areas, forest, rivers)
• physical factors

  • there are physical attributes/make-ups of a physical environment (air, water, temperature, light etc.)
  • measured using data loggers and temperature probe
  • organisms need to adapt to these factors in order to survive
• the two classifications of adaptive traits

  1. structural
  2. behavioural
• structural adaptive traits

  • physical characteristics of an organism that helps to survive well in its habitat
  • Example: scales on crocodile that protect it from heat and injury
• Behavioural adaptive traits

  • behaviours developed by an organism to survive
  • Example: migratory birds moving from the North to the South which helps them avoid the harsh winter season
• two unique habitats on earth

  1. Rainforest
  2. Mangrove Swamp
• physical factors in rainforest

  • has warm air with high humidity
  • frequent and abundant rainfall
  • high daily temperature (average)
  • stable weather conditions
  • abundant sunlight
  • plentiful minerals
  • usually acidic soil
• RAINFOREST CASE STUDY #1 : king cobra

  structural:

  • hunts during dawn/dusk
  • lifts body up and hisses to frighten enemies
  • aggressive when provoked

  behavioural:

  • poisonous venom aids in hunting
  • keen sense of smell
  • body colour to camouflage with the floor
  • inner ears to detect vibrations
• RAINFOREST CASE STUDY #2 : stick insect

  structural:

  • shape and colour like a leaf/twig, makes it difficult for predators to spot it

  behavioural:

  • stays very still
  • moves very slowly to avoid being detected by predators
• RAINFOREST CASE STUDY #3: banded leaf monkey

  structural

  • long and strong arms to help swing from tree to tree

  behavioural

  • stays in group = protection from predators and to fight off other groups trying to take their territory
• RAINFOREST CASE STUDY #4: velvet tamarind tree

  structural

  • their buttress root provides support to 1. grow very tall and to 2. absorb minerals from the soil's surface

  behavioural

  • grow very tall so leaves can trap more sunlight
• RAINFOREST CASE STUDY #5: pangolin

  structural

  • covered with scales for protection
  • long and sticky tongue to catch ants and termites
  • strong front legs and claws to dig

  behavioural

  • curl into a ball to protect itself against predators
  • active mostly at night to avoid day predators
• physical factors in mangrove swamp

  • trees are immersed in seawater at high tide
  • and becomes dry at low tide
  • receive fresh water when it rains
  • a lot of sunlight exposure
  • salty and carries many minerals
  • seawater sightly alkaline
• MANGROVE CASE STUDY #1: mangrove tree

  structural:

  • strong roots to anchor securely to the mud
  • breathing roots to obtain oxygen from the air
  • ability to remove salt by shredding off leaves
• MANGROVE CASE STUDY #2: pistol shrimp

  structural

  • have enlarged claws > shoots a jet with a water bubble, which bursts in the water with a high pressure = catches prey off guard

  behavioural

  • lives in burrows to protect itself against predators
• MANGROVE CASE STUDY #3 : kacang putih moth

  structural

  • brown coloured body and wings to camouflage with tree trunks = difficult for predators to spot it

  behavioural

  • larvae roll up the edge of leaves like kacang putih paper = protect against predators
• MANGROVE CASE STUDY #4: mangrove snail

  structural

  • thick shell that provides protection
  • colour of the shell to camouflage
  • produces and release mucus
  • strong muscle to cling on tree to avoid being washed away

  behavioural

  • climbs tree to avoid high tide and predators
  • hides in cracks/rocks to cool them
  • active during low tide
• MANGROVE CASE STUDY #5: MUDSKIPPER

  structural:

  • large gill chambers to store water
  • absorb oxygen both on land and water
  • eyes on top of head to help scan and detect on preys and predators

  behavioural:

  • feeds on food found on mud surface
  • digs burrow for protection and keeps them cool and moist
• what is an organism?

  a living thing adapted to the environment it lives in
• what is an ecosystem?

  organism > population (same kind of organisms + living in same environment) > community (different populations) > ecosystem (interactions between a community and its physical environment)
• the three types of inter-relationships in an ecosystem are predator-prey, mutualism and parasitism.
• predator-prey

  the relationship is predators hunting and killing their preys for food
• usual adaptive traits of predators

  • strong body and claws
  • great strength
  • sharp teeth
  • high speed
  • sharp senses to detect preys
  • produce chemicals to lure/poison/paralyse preys
  • camouflage to deceive/trick preys
• usual adaptive traits of preys

  • high speed
  • small size
  • effective camouflage
  • defensive body parts (horns)
  • mimic unpleasant things (smell, sight) to fool predators
  • release chemicals to frighten predators
• what is a mutualism relationship?

  • two or more organisms supporting/benefitting one another in a habitat
  • one common way is one protects, the other provides food
• MUTUALISM RELATIONSHIP: #1 Ant and Aphid

  Aphids: little sap-sucking insects that produce honeydew (sugary liquid)

  ANTS

  • attracted to honeydew produced by aphids
  • "milk" them by stroking them with their antennae

  APHIDS

  • ants protect them from predators and parasites
• MUTUALISM RELATIONSHIP: #2: Clownfish and Sea anemone

  clownfish:

  • protected from sea anemone's tentacles

  sea anemone:

  • brightly coloured clownfish lures predators which becomes a food source for the sea anemone
  • active movement of clownfish creates currents to obtain oxygen