Unit 8: Conservation Biology and Global Changes

What are the three main levels of biodiversity?

Genetic diversity, species diversity, ecosystem diversity

Why is biodiversity important for ecosystem stability?

More diverse ecosystems are more stable and can resist threats better.

How is biodiversity important to medicine?

Many important drugs come from plants, fungi, and bacteria.

Why is genetic diversity important for species survival?

It helps species survive new diseases and environmental changes.

What are the four major threats to biodiversity?

Habitat loss, introduced species, overharvesting, and global change.

What is acid precipitation?

Rain, snow, or fog with a pH less than 5.2 caused by pollution.

How does acid precipitation form?

Burning wood and fossil fuels releases sulfur and nitrogen oxides, which form acids when they mix with water.

What does population conservation focus on?

Population size, genetic diversity, and protecting critical habitats.

What is a minimum viable population (MVP)?

The smallest population size needed to survive and avoid extinction.

What is an extinction vortex?

When small populations lose genetic diversity and spiral toward extinction.

Why is genetic variation important for populations?

It allows species to adapt to environmental changes, like new diseases.

How does landscape structure affect biodiversity?

More habitat fragmentation and edges decrease biodiversity.

What are movement corridors?

Strips of land that connect isolated habitats and help species move and survive.

What is a biodiversity hot spot?

A small area with lots of unique (endemic) species and many endangered species.

How do humans alter nutrient cycling?

Agriculture removes soil nutrients and adds too much nitrogen to water systems.

What is biological magnification?

Toxins become more concentrated as they move up the food chain.

Name some toxins that cause biological magnification.

Mercury, lead, and DDT.

Why are pharmaceuticals a concern for ecosystems?

Drugs from human use end up in freshwater, affecting organisms.

What is the greenhouse effect?

Heat is trapped by gases like CO₂ and water vapor, warming Earth.

How have human activities affected CO₂ levels?

Deforestation and burning fossil fuels have increased CO₂ levels over the last 150 years.

What is climate change?

Long-term (30+ years) changes to Earth’s climate.

Which ecosystems are warming the most?

Far northern ecosystems (like the Arctic).

What happens when Arctic snow and ice melt?

Darker surfaces are exposed, absorbing more heat and causing more warming (positive feedback).

What is positive feedback in climate change?

A change (like melting ice) that causes even more warming.

What is the role of the ozone layer?

It protects Earth from harmful UV radiation.

How have humans damaged the ozone layer?

Chlorine-containing chemicals (like CFCs) break down ozone.

Why is ozone depletion dangerous?

More UV radiation reaches Earth's surface, increasing DNA damage.