Biology

• Biodiversity


  The variety of all the different species of organisms (plant, animal, and microorganism) on Earth, or within a specific ecosystem
• High biodiversity


  • Ensures the stability of an ecosystem, because it reduces the dependence of one species on another in the ecosystem for food or habitat maintenance
• Human activities, such as deforestation


  Reducing biodiversity
• Waste management


  Rapid growth of the human population and increases in the standard of living mean humans are using more resources and producing more waste
• Types of pollution


  • Water pollution (from sewage, fertiliser run-off, or toxic chemicals)
  • Air pollution (from smoke and acidic gases)
  • Land pollution (from landfill and toxic chemicals)
• Global warming


  The gradual increase in the average temperature of the Earth
• Levels of carbon dioxide and methane in the atmosphere are increasing due to human activity, contributing to global warming and climate change
• The scientific consensus on global warming is based on systematic reviews of thousands of peer-reviewed publications
• Effects of global warming

  • Large-scale habitat change and reduction, causing decreases in biodiversity
  • Extreme weather and sea level changes
  • Migration of species to different parts of the world, affecting ecosystems
  • Threats to the security and availability of food
• Deforestation


  Large-scale deforestation in tropical areas has been carried out to provide land for cattle and rice fields, and to grow crops for biofuels
• Consequences of deforestation


  • Large amounts of carbon dioxide being released into the atmosphere due to burning of trees
  • Extinctions and reductions in biodiversity as habitats are destroyed
  • Climate changes, as trees absorb carbon dioxide and release water vapour
• Intensive farming techniques


  Make food production more efficient by restricting energy transfer from food animals to their environment
• Intensive farming practices


  • Limiting the movement of animals
  • Controlling the temperature of their surroundings
  • Feeding animals high-protein foods to increase growth
  • Giving animals antibiotics to prevent or treat disease
  • Regularly using fertilisers, herbicides, and pesticides on crops
• Sustainable fisheries


  Controlling net sizes (bigger holes to stop young fish being caught) and fishing quotas (how many fish can be caught) in many places to avoid overfishing and maintain fish stocks
• Food security


  Having enough food to feed a population
• Factors threatening food security

  • Rapid population growth and increasing birth rate in some countries
  • Changing diets in developed countries, requiring scarce food resources to be transported globally
  • New pests and pathogens impacting farming of vast amounts of crops
  • Environmental changes, such as drought, affecting food production
  • Increasing cost of agricultural inputs, like fertilisers
  • Conflicts in some parts of the world, which affect the availability of water or food
• Role of biotechnology


  Scientists can use new technologies to solve problems around food production for a growing population
• Biotechnology applications


  • Using the fungus Fusarium to make mycoprotein, a protein-rich alternative to meat
  • Culturing Fusarium in aerobic conditions in fermenters
• Benefits of biotechnology


  • High yield and quicker growth of crops and animals
  • Efficient use of food, with less waste produced
  • Can meet demand for food from a rapidly increasing population
• Concerns about biotechnology


  • Increased risk of antibiotic-resistant bacteria strains
  • Pesticides and herbicides may kill beneficial organisms and reduce biodiversity
  • Ethical issues about animal welfare and quality of life
  • Large carbon dioxide and methane emissions
• Biodiversity refers to the variety of living things on earth, including different species, populations, communities, ecosystems, and genetic diversity within species.
• Terrestrial biomes include forests, grasslands, deserts, tundras, and wetlands.
• Biomes are large areas with similar climates, vegetation, and animal communities.
• The loss of biodiversity is known as extinction, where one or more species become permanently lost due to various factors.
• Marine biomes include coral reefs, kelp beds, open ocean, and coastal zones.
• Factors affecting biodiversity include climate change, habitat loss, pollution, overexploitation, invasive species, and natural disasters.
• The importance of biodiversity includes maintaining ecological balance, providing resources for human needs, preserving cultural heritage, promoting scientific research, and contributing to economic development through eco-tourism and sustainable agriculture.
• Habitat destruction occurs when natural habitats such as rainforests, savannas, and wetlands are cleared for agriculture, urbanization, mining, logging, or other human activities.