The Effect of Genetic Mutations Mutations occur?spontaneously?and?randomly?during DNA replication As the DNA base sequence determines the sequence of amino acids that make up a protein,?muta...
Required Practical: Investigating Factors Affecting Species Distribution Understanding how to investigate the effects of?named environmental factors?on the?distribution?of a?given species?is an imp...
Conservation & Human Need Humans use many?resources?from the Earth such as?land?(for settlements and agriculture),?water,?wood?and?fossil fuels As the human?population?increases?and coun...
Apparatus & Techniques: Investigating Growth Rate Using Turbitity Measurements The?population growth rate?of microorganisms, such as bacteria or yeast, can be investigated by growing the...
Edexcel IGCSE Biology 復習筆記 2.7.5 Human Gas Exchange System Structure of the Breathing System The lungs are the gas exchange surface in humans All gas exchange surfaces have features in common w...
Primary Succession Ecosystems are?dynamic, meaning that they are constantly?changing Sometimes, ecosystems change from being very?simple?to being relatively?complex This process is known as?...
Ecosystems are Dynamic Ecosystems Species?do not exist by themselves in their own isolated environment, they interact with other species forming a?community The species within a community in...
Edexcel IGCSE Biology 復習筆記 2.7.4 Practical: The Effect of Light on Gas Exchange in Plants Practical: The Effect of Light on Gas Exchange in Plants Apparatus Boiling tubes Cotton wool Alu...
Edexcel IGCSE Biology 復習筆記 2.7.3 Plants: Gas Exchange in Photosynthesis & Respiration Gas Exchange: Photosynthesis & Respiration The processes of?respiration?and?photosynthesis?b...
Estimating the Size of a Population Measuring all the different levels of biodiversity within an ecosystem could be very?time consuming Finding out which species live in an ecosystem and the...
Edexcel IGCSE Biology 復習筆記 2.7.2 Leaf Structure Leaf Structure The structure of the leaf is adapted to carry out both photosynthesis and gas exchange The different cell types (palisade m...
Carrying Capacity The?maximum stable population size?of a species that an?ecosystem?can?support?is known as the?carrying capacity Every individual within a species population has the?potenti...
