Year 9 Science 2012 Ecosystems

Natural Ecosystems Organisms live surrounded by other organisms and by non-living things such as rocks, water and soil Animals can be chased by predators, attached by diseases and battered by storms Plants can be eaten, suffer drought or be destroyed by fire

However, not all organisms compete with or harm each other Some live together and help each other survive

Ecology Ecology is the study of how organisms interact with each other and with their environment The environment consists of all the factors in organism’s surroundings that affect it A habitat is where an organism lives (the habitat is a place were an environment is, a set of factors that effect survival)

Ecosystems An ecosystem is a system formed by a group of living things interacting with each other and their non-living surroundings An ecosystem has three main parts: Physical surroundings, such as rocks, soil and water Living organisms Living and non-living factors that make up the environment

Factors influencing organisms: Non-living factors: abiotic factors or physical factors Include: water, air quality, light, temperature etc. Living factors: biotic factors Include: predators such as sharks, parasites, fungi

What do I remember? – These are wrong? Word Wrong Meaning?? Ecology Where an organism lives Habitat The study of how organisms interact with each other and their physical surroundings Ecosystem All the factors in a organisms surroundings that affect it Environment The place where organisms and their physical surroundings from a balanced environment that is different from others nearby

Word Meaning Ecology The study of how organisms interact with each other and their physical surroundings Habitat Where an organism lives Ecosystem The place where organisms and their physical surroundings from a balanced environment that is different from others nearby Environment All the factors in a organisms surroundings that affect it Habitat Your room Ecosystem Your House Environment Your school

Abiotic Factors: Non-Living Factors Water: Water is essential for all of the chemical reactions in the cells of living things

Temperature: Heat effects the speed of chemical reactions in cells The higher the temperature, the faster these reactions take place

Temperature and Activity: Page 289 Design and Conduct your own experiment

H:students/Y9/Science/cra Science/Y9 Science2012/Ecology Plan

Ectothermic: Some animals such as fish and reptiles depend on the temperature of their environment They might lay on warm rocks in the sunlight to heat up or hide in a burrow if they are too hot

Ectothermic organisms: Biologists describe these animals as ectothermic (rather than ‘cold blooded’) Ectothermic means that organisms must obtain body heat from the environment rather than by generating it internally by body chemistry

Endothermic organisms: Birds and animals, like humans and kangaroos are “warm blooded” or endothermic Endothermic means that the organisms have the ability to generate heat internally and control heat loss to keep their body temperature constant

Fire: Abiotic Factor Bush fires can kill some plants and hep others Many Australian plants will germinate (start to grow) after a fire due to the chemicals released in the smoke

Activity Book 9.1 Smoke and Germination Complete for H/W due Thursday 23rd February This Thursday!

Light: Abiotic Factor Light is needed for photosynthesis Photosynthesis is the process by which plants make their food materials using water, carbon dioxide and light

Soil Type: Abiotic Factor Not all soils are the same Some soils hold more nutrients than others Some soils hold water better than others

Gas Levels: Abiotic Factor Most organisms need oxygen for respiration Respiration is the reaction of food with oxygen to give energy (heat) In water the amount of oxygen can vary – cold water has more oxygen than warm water

Biotic Factors: Living Things The living things that surround an organism are called a Community There are many different interactions between living things

Competition: Biotic Factor Organisms are said to be in competition when they both try to get the same resource, which might only exist in limited amounts Competition occurs between members of the same species and between different species

Predation: Biotic Factor When one organisms kills and eats another, the attacker is called a predator and the one being eaten is called the prey

Mutualism: Biotic Factor Mutualism is a relationship when tow organisms live closely together and both benefit

Parasitism: Biotic Factor Parasitism is a relationship where one organism lives on or in another organism (the host) and feeds off it The parasite cannot survive without the organism in which it lives

Commensalism: Biotic Factor Commensalism is a relationship when one organism benefits and the other is unaffected

Skill Builder: Defining Relationships See page 286

Adaptations: To survive with the various biotic and abiotic factors in their environments, organisms have special features called adaptations that assist them to survive An adaptation is a feature that helps an organism survive and reproduce in its environment

Structural Adaptations A structural adaptation is a body part that helps an organism to survive.

Behavioural Adaptations: A behavioural adaption is a feature of an organism’s habits, actions or way of life that helps it For example, the spinifex hopping mouse, shown in Figure 9.1.15, only comes out at night when the air has cooled, so that it does not lose water and dehydrate. The mouse avoids the heat of the day by remaining in its burrow. A burrow is cooler and the air there is humid, with a lot of moisture in the air. This helps to slow the evaporation of moisture from the mouse. Dolphins use a behaviour called echolocation. When they want to know what is in the water around them, they emit clicking sounds, as shown in Figure 9.1.16. These sound waves travel through water, reflect off objects and return to the dolphin. The dolphin has the ability to receive these sound waves and form a mental image of the objects around it.

The large-eared horseshoe bat (Figure 9. 1 The large-eared horseshoe bat (Figure 9.1.17) also echolocates its prey. It sends out high-pitched sounds through its nose, which has a structure called a noseleaf that focuses the sound into a beam. The bat moves its ears and head around to locate the returning sounds that have bounced off its prey. The bat's brain creates a 'picture' in its head of where the prey is located.

Functional Adaptations: A functional adaptation is a feature of the way an organism’s body works eg: when you exercise, your body automatically makes your heart go faster so more blood is supplied to your muscles It happens automatically – you cannot consciously control it

Unit Review: Page 288 Remembering Understanding Applying Analysing Evaluating Creating Inquiring: Allocated to pairs of students each week