11.1 - Biodiversity Flashcards
What does biodiversity refer to?
Biodiversity refers to the variety of living organisms present in an area, including plants, animals, fungi, and other living things. It ranges from large organisms like giant redwood trees to single-celled algae.
Why is biodiversity important?
Biodiversity is essential for maintaining a balanced ecosystem. All species are interconnected, depending on each other for survival. For example, trees provide homes for animals, animals eat plants, plants need fertile soil, and fungi help decompose dead matter, returning nutrients to the soil.
What happens in areas with reduced biodiversity?
In areas with reduced biodiversity, the interconnected relationships between species may be disrupted, leading to harm to all species in the ecosystem. This can impact the overall stability of the ecosystem.
How do balanced ecosystems benefit humans?
Balanced ecosystems provide humans with food, oxygen, and other essential materials necessary for survival.
How do human activities affect biodiversity?
Human activities like farming and land clearance for housing can reduce biodiversity, harming the stability and balance of ecosystems.
Which regions of the world have the highest biodiversity?
Tropical moist regions with warm temperatures year-round have the most biodiversity, such as the Amazon Rainforest.
Which regions have the least biodiversity?
Very cold areas, such as the Arctic, and very dry areas, such as deserts, have the least biodiversity.
How does the proximity to the equator affect biodiversity?
The closer a region is to the equator, the greater its biodiversity. For example, the Amazon Rainforest has over 40,000 plant species, while Northern Canada has less than 3,000.
Why is measuring biodiversity important?
Measuring biodiversity helps scientists monitor species present in an area, creating a baseline to assess the effects of changes in the environment, such as human activity, disease, or climate change.
What is an Environmental Impact Assessment (EIA)?
An Environmental Impact Assessment (EIA) is undertaken before a major project, like road building or creating a new nature reserve, to predict the positive and negative effects on the area’s biodiversity.
What are the three levels of biodiversity studied?
The three levels of biodiversity are:
- Habitat biodiversity
- Species biodiversity
- Genetic biodiversity
What is habitat biodiversity?
Habitat biodiversity refers to the number of different habitats found within an area. A greater number of habitats typically leads to greater species biodiversity.
What is an example of high and low habitat biodiversity?
The UK has a variety of habitats (e.g., meadows, woodlands, streams), giving it high habitat biodiversity. Antarctica, mostly covered by ice sheets, has low habitat biodiversity.
How does the countryside affect habitat biodiversity?
A diverse countryside with various habitats like rivers, woodlands, hedgerows, and wild grasslands supports more species, while uniform landscapes with large ploughed fields have lower habitat biodiversity.
What is species biodiversity?
Species biodiversity includes two components:
- Species richness – the number of different species in an area.
- Species evenness – the comparison of the numbers of individuals of each species in a community.
How does species evenness affect biodiversity?
Even if two areas have the same number of species, their species evenness can differ. For example, a cornfield may have 20 species, but corn will dominate, making the community less even compared to a grass meadow where species populations are more balanced.
What is genetic biodiversity?
Genetic biodiversity refers to the variety of genes within a species. It is the genetic differences between individuals of the same species, which can lead to different characteristics within a population.
How does genetic biodiversity affect a species?
Greater genetic biodiversity allows a species to better adapt to changing environments and increases the likelihood of individuals being resistant to diseases.
How many genes do humans have?
Humans have about 25,000 genes.
Can genetic biodiversity lead to variations within a species?
Yes, genetic biodiversity can cause variations in characteristics, such as coat length and color in dogs, due to the different alleles (versions of genes) present in the population.
