levo

Ecosystems Under Stress

Biodiversity Levels and Causes of Decline

  • 4 things to know
  • Component 1

Overview

Recall questions on genetic, species and ecosystem diversity, species richness and evenness, local trends, extinction rates and threatened hotspots, and on overexploitation, invasive species, pollution and climate change as causes of decline, phenological mismatch and metrics of loss.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

What are the three levels at which biodiversity is measured?

Key term

What is species evenness?

Key term

Which two ecosystem types are biodiversity hotspots experiencing particularly severe global declines?

Process

Define genetic diversity, species diversity and species richness.

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What are the three levels at which biodiversity is measured?

    Model answer

    Genetic diversity within species, species diversity within communities, and ecosystem diversity across landscapes

  2. 2

    Define genetic diversity as a component of biodiversity.

    Model answer

    The variation in alleles and genotypes within a population or species

  3. 3

    What does species diversity refer to as a level of biodiversity?

    Model answer

    The variety of different species within a community, encompassing both the number of species present and their relative abundances

  4. 4

    Define species richness.

    Model answer

    The number of different species present in a community or area

  5. 5

    What is species evenness?

    Model answer

    The relative abundance of each species within a community

  6. 6

    What is ecosystem diversity?

    Model answer

    The variety of different habitats, biological communities and ecological processes within a region

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Water and Carbon Cycles
Hot Desert Systems and Landscapes
Coastal Systems and Landscapes
Glacial Systems and Landscapes

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

China and .
IndiaAustraliaJapan

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AThe horns have less sand volume, so they move more quickly.
BSand is transported up the gentle windward slope via saltation.
CSand accumulates at the crest.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

Weathering means breakdown of rock in place.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Ecosystems Under Stress, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.