20.1.7Human Influences on Ecosystems
Reasons for Conservation — Cambridge IGCSE Biology 0610 Revision Notes & Topical Questions
5 min read 5 parts Lesson 7 of 7 Unit quiz
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
Section 1 of 5Why Conserve Species and Habitats
Conservation protects living things and the services that ecosystems provide to humans.
Biodiversity
- Biodiversity Keeping a wide variety of species helps ecosystems remain stable when conditions change.
Preventing extinction
- Preventing extinction Protecting endangered species keeps iconic organisms and avoids permanent loss of their genes.
Vulnerable ecosystems
- Vulnerable ecosystems Some habitats would be lost quickly to human activity unless they are deliberately protected.
Ecosystem functions
- Ecosystem functions Healthy ecosystems cycle nutrients, and processes such as the carbon cycle help limit climate change.
Section 2 of 5Resources From Wild Species
Many human needs are met directly by wild organisms.
Resources From Wild Species
Food
- Food Conserving crops, livestock relatives and fish helps make sure there is enough food for the human population.
Drugs
- Drugs Wild plants may contain useful chemicals, so losing them removes possible sources of plant-based remedies.
Fuel
- Fuel Wood and plant material provide fuel for important activities such as cooking in many communities.
Genes
- Genes A wide gene pool in every species keeps variation available for breeding programmes and adaptation.
Section 3 of 5Captive Breeding Techniques (Extended)
Zoos and reserves use reproductive technology to build up numbers while keeping genetic variety.
1
In artificial insemination sperm from a male is placed into the reproductive tract of a female, for example with a syringe.
2
Sperm can be transported between zoos around the world, so the animals themselves do not have to be moved.
3
In vitro fertilisation egg cells are fertilised by sperm in a laboratory rather than inside the female.
4
The fertilised egg cell can then be implanted into a female, which carries the offspring through development.
5
Using gametes with known alleles helps ensure the next generation stays genetically diverse.
Section 4 of 5Risks to Small Populations (Extended)
Reduced variation
- Reduced variation When a population shrinks, fewer alleles remain, so genetic variation in the species falls.
Environmental change
- Environmental change A species with little variation is more likely to be affected by disease or a changing environment.
Lower resilience
- Lower resilience Without variation, fewer individuals may have features that let them survive a new challenge.
Extinction risk
- Extinction risk Low resilience means a greater chance that the whole species will die out.
Section 5 of 5Exam Checklist & Tips
20.1.7 – Key Points for the Exam
- Conservation Protecting and managing species and habitats to maintain biodiversity.
- Artificial insemination Placing sperm into a female reproductive tract without natural mating.
- In vitro fertilisation Fertilising egg cells with sperm in a laboratory before implanting an embryo.
- Gene pool The full range of alleles present in a population or species.
- Extinction The complete disappearance of a species.
Common Mistakes
- Saying conservation is only about saving cute animals; it also protects ecosystems, resources and genes.
- Confusing artificial insemination, which places sperm in the female, with IVF, where fertilisation happens in a laboratory.
- Forgetting to link a smaller population to lower genetic variation and then higher extinction risk.
- Writing that sperm is moved between zoos instead of stating that this avoids transporting whole animals.
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