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Biology N5
Life On Earth
| Question | Answer |
|---|---|
| Biomes | Seperate geographical areas that have the same climate (temperature and rainfall) and have similar flora and fauna. |
| Ecosystem | Natural biological system made up of all the living and non-living things in an area. |
| When does competition between organisms occur? | When organisms use same resource that is short supply. |
| What do plants growing in the same habitat compete for? | They compete for light, space and water. |
| What do animals living in the same habitat compete for? | They compete for habitat, space, prey/food and friends. |
| When competition becomes intense, what happens to biodiversity? | It decreases. |
| What are the three main factors that have affect on biodiversity? | Biotic, Abiotic and Human |
| What does abiotic mean? | Non-living |
| What does biotic mean? | Linked to living things. |
| Give examples of Abiotic factors | pH, temperature, (soil) moisture, light intensity |
| Give examples of Biotic factors | Grazing, Predation, Food availability, Disease, Competition |
| Explain Grazing | When herbivores feed on plants. |
| Explain Predation | When one organism hunts another and can affect many species within an ecosystem. |
| Explain the term Niche | An organisms role within an ecosystem. |
| Explain Paratism | When one organism feeds from a host. Only the parasite benefits. It is usually harmful for the host. |
| What are Producers? | Green plant, produces its own food by photosynthesis. |
| What are consumers? | An animal that eats another organism to consume its energy. |
| Why is nitrogen essential for organisms? | To make protein for growth and repair. |
| Explain Nitrifying bacteria | Convert ammonia to nitrites |
| Explain Denitrifying bacteria | Breaks down nitrates and release nitrogen gas into the air. |
| Explain Root nodule bacteria | Absorb atmospheric nitrogen and fix into nitrate. |
| Explain Free-fixing soil bacteria | Absorb atmospheric nitrogen and fix into nitrate. |
| Explain Decomposers | Break down waste and dead bodies and release ammonium compounds containing nitrogen into the soil. |
| What three main nutrients are found in fertilisers? | Nitrogen Potassium Phosphorus |
| What is the purpose of Nitrogen? | Growth of leaves and stems |
| What is the purpose of Potassium? | Flowers and fruit |
| What is the purpose of Phosphorus? | Roots |
| What is a mutation? | Change in an organisms genetic material (genes). |
| What environmental factors can increase the rate of mutation? | Mutagenic Agents Some types of radiation Certain chemicals |
| Why is variation important? | It is the process by which alleles of genes are produced. |
| What is an adaption? | Inherited characteristic that makes an organism well suited to it's environment. |
| State the three ways of adaption present in organisms | Structural Physiological Behavioural |
| What is a stimulus? | Changes in the environment. |
| Why is it important that animals learn to respond to a changing environment? | So they can survive and reproduce. |
| Describe two types of behavioural adaptions shown by animals | Migration Hiberation |
| What is a species? | Organisms that look similar and reproduce to produce fertile offsprings. |
| What is speciation? | It is the formation of new species. |
| What are the three types of Isolating Mechanism? | Geographical Ecological Reproductive |
| What is Geographical Isolation? | Species occur in different areas, which are often seperated by a physical barrier such as a river or mountain range. |
| What is Ecological Isolation? | Species occur in the same areas,but they occupy different habitats and rarely encounter each other. |
| What is Reproductive Isolation? | Species reproduce in different seasons or at different times of the day. |
| What are indicator species? | Organisms (plant/animal/insect) that indicate level of pollution of an area without the need for chemical tests. |
| State 2 alternatives to mitigate the effects of intensive farming on the environment | Battery Farming Monoculture |