IB MYP 4-5 Biology-Biodiversity- Study Notes - New Syllabus

IB MYP 4-5 Biology-Biodiversity- Study Notes – New syllabus

IB MYP 4-5 Biology-Biodiversity- Study Notes – IB MYP 4-5 Biology – per latest IB MYP Biology Syllabus.

Key Concepts:

Species diversity and classification
Importance of biodiversity
Threats to biodiversity

IB MYP 4-5 – Biology-Concise Summary Notes- All Topics

Species Diversity and Classification

What is Species Diversity?

Species diversity refers to the number of different species and the variety of life forms in a particular habitat or on Earth as a whole.

It’s a key part of biodiversity and includes:

Species richness – How many different species are present
Species evenness – How evenly individuals are spread across species

The more diverse an area is, the more balanced, stable, and healthy its ecosystem tends to be.

Example: A tropical rainforest has high species diversity; a desert has low species diversity.

Why is Species Diversity Important?

Supports ecosystem balance
Increases chances of survival and adaptation
Provides food, medicine, and oxygen
Helps in natural recycling (e.g., carbon and nitrogen cycles)

What is Classification?

Classification is the process of grouping living organisms based on shared features. It helps scientists to:

Identify species easily
Study relationships and evolution
Understand how life on Earth is connected

It brings order to the variety of life by placing organisms into categories.

Levels of Classification:

Level	Example (Human)
Kingdom	Animalia
Phylum	Chordata
Class	Mammalia
Order	Primates
Family	Hominidae
Genus	Homo
Species	sapiens

Together, genus + species = scientific name
Example: Homo sapiens (modern humans)

Types of Classification

Type	Based on…	Example
Artificial	One or two simple traits	Size, color
Natural	Many traits + evolutionary links	Internal and external features
Phylogenetic	Genetic and evolutionary history	DNA analysis, common ancestors

Binomial Nomenclature – Scientific Naming

Every organism has a 2-part name:
- Genus (capitalized)
- Species (lowercase)
- Written in italics or underlined
Example: Panthera leo (lion)

Why use it?
Universal system
Avoids confusion from local names

How Does Classification Link to Species Diversity?

Helps track biodiversity and protect endangered species
Allows comparison between species
Supports conservation and ecosystem research

Summary:

Species diversity refers to the variety of organisms in a habitat.
Classification organizes these organisms by similarities and ancestry.
Both are essential for studying life, protecting species, and understanding evolution.

Importance of Biodiversity

What is Biodiversity?

Biodiversity means the variety of life on Earth including all plants, animals, fungi, and microorganisms, as well as the ecosystems they live in.

It includes:

Species diversity – different kinds of living things
Genetic diversity – differences within a species
Ecosystem diversity – variety of habitats like forests, oceans, deserts

The more diverse life is, the more balanced, resilient, and productive our world becomes.

Why is Biodiversity Important?

1. Supports All Life on Earth: All species from tiny bacteria to tigers are part of a complex web. If one disappears, it can affect the whole system.

Example: Bees help pollinate plants. No bees = fewer crops = less food.

2. Provides Essential Resources

Resource	Example
Food	Fruits, vegetables, fish, grains
Medicine	Over 50% of drugs from nature (e.g., aspirin from willow bark)
Raw materials	Wood, cotton, natural oils

We rely on living organisms every single day – often without even realizing it.

3. Maintains Ecosystem Balance

Biodiversity helps regulate natural processes like:

Water purification
Air quality
Climate control
Nutrient cycling

Forests absorb CO₂ and release oxygen – a natural air filter!

4. Protects Against Disease and Pests

A mix of species makes it harder for diseases to spread.
Monocultures (just one species) are more vulnerable to pests and infections.

5. Enables Adaptation and Evolution

Genetic diversity within species helps them adapt to changing conditions.
It also gives nature the raw material for evolution over time.

6. Cultural and Economic Value

Biodiversity enriches traditions, tourism, and art.
Ecotourism (wildlife parks, safaris, marine diving) generates income and jobs.
Example: The Great Barrier Reef attracts millions of tourists and supports local communities.

Summary Table – Importance of Biodiversity

Importance Area	Role of Biodiversity
Environmental	Maintains ecosystem functions and balance
Biological	Supports evolution and species survival
Economic	Source of food, medicine, and industry
Social/Cultural	Enriches human culture, recreation, and tourism
Global Stability	Regulates climate, air, and water cycles

What Happens If We Lose Biodiversity?

Ecosystem collapse (e.g., no pollinators = no food)
Increase in natural disasters (e.g., floods, desertification)
Loss of medical discoveries
Hunger and poverty rise
Climate becomes more extreme and unpredictable

Every species lost is a permanent loss of something that could have helped us survive.

Threats to Biodiversity

Why Biodiversity Is in Danger?

Biodiversity – the rich variety of life on Earth – is declining faster than ever before.
Species are disappearing, ecosystems are becoming weaker, and the balance of nature is being disturbed.

Main Threats to Biodiversity

1. Habitat Destruction

Humans cut down forests, build cities, drain wetlands, or pollute rivers — destroying homes of plants and animals.

Examples:
– Deforestation in the Amazon
– Coral reef bleaching due to coastal pollution

No habitat = no survival.

2. Pollution

Chemicals, plastics, oil spills, and sewage damage air, water, and soil where organisms live.

Examples:
– Plastic in oceans harming turtles and fish
– Air pollution affecting bees and birds

Pollution causes illness, lowers reproduction, and kills wildlife.

3. Overexploitation

Over-hunting, overfishing, and overharvesting stop species from recovering naturally.

Examples:
– Overfishing of tuna and sharks
– Elephant poaching for ivory

Nature needs time to balance itself – overuse leads to collapse.

4. Climate Change

Global warming affects seasons, temperatures, sea levels, and rain cycles.

This disrupts animal migration, plant blooming, and survival of many species.

Example: Coral reefs are bleaching and dying due to warm ocean temperatures.

5. Invasive Species

Non-native species introduced by humans spread and disrupt local food chains.

Examples:
– Water hyacinth choking Indian lakes
– Rats on islands eating bird eggs

Invasive species often destroy native balance and cause extinctions.

6. Loss of Genetic Diversity

Smaller populations = less genetic variety = weaker survival abilities.

Example: Cheetahs have very low genetic diversity – making them vulnerable to diseases and changes.

Final Summary – Key Threats

Threat	Impact on Biodiversity
Habitat loss	Species lose homes → extinction
Pollution	Poisoning of organisms and habitats
Overuse of resources	Species cannot recover → decline
Climate change	Forces species out of their comfort zones
Invasive species	Destroys balance in native ecosystems
Genetic erosion	Less survival ability over generations

Why This Matters

Less food and clean water
Weaker ecosystems and fewer services (e.g., pollination, air cleaning)
Higher risk of disease spread to humans
Loss of natural beauty and wonder

Once a species is gone, it’s gone forever. Every loss reduces Earth’s ability to support life.

IB MYP 4-5 Biology-Biodiversity- Study Notes

IB MYP 4-5 Biology-Biodiversity- Study Notes - New Syllabus