Class notes
Bio 102 Exam 1 Review Notes
- Course
- BIO 102
- Institution
- University Of Rhode Island
This is a comprehensive and detailed review note on Exam 1 for Bio 102. *Essential Study Material!!
[Show more]
Content preview
Biological diversityBiodiversity-the diversity of life
3 main levels:
-genetic
-species
-ecosystem
Species diversity
-usually quantified in two ways:
1.species richness: is a count of the species present in a defined region
2.Species evenness:measurement of how evenly distributed organisms are among species (the
relative abundance of each species present)
For any given species richness:
Higher species diversity if evenness is high-that is, if all species have a comparable abundance
Lower species diversity:one or just a few species dominate a community
How to measure species diversity
-transects, traps, quadrants, mark-and-recapture techniques
-DNA barcoding: uses a well-characterized gene sequence to identify distinct species.
Sequences of target genes are matched to reference libraries.
Genetic Diversity
-measured as the number and relative frequency of all genes (and their alleles) present in a
species
-key for adapting to changing environments
→how?
-genome sequencing
-environmental sequencing
Ecosystem diversity
-highest level of biodiversity
-the number of different ecosystems on the planet within a given geographic area
Biodiversity can be recognized and quantified on several distinct levels, but it is also dynamic, it
changes through time
Why are biodiversity and ecosystem function important?
-ecosystem function: sum of the biological and chemical processes that are characteristic of a
given ecosystem (primary production, nitrogen cycling, decomposition, and carbon cycling)
-species richness increases aspects of ecosystem function:
-productivity
, -resilience
-resistance
Importance of biodiversity to humans
-human health
-agricultural diversity
-wild food sources
-psychological and moral value
-collectively, all direct and indirect benefits that humans derive from organisms and ecosystems
they compose are called ecosystem service
-ecosystem services have been estimated to have a value of US $125 trillion per year
Mass extinctions are “normal” on Earth
-species are vanishing faster than at virtually any other time in Earth’s history
-modern rates of extinction are 100 to 1000 times greater than average rate
-sixth mass extinction in the history of multicellular life
What can we do to protect it?
-biodiversity hotspots
Problems with hotpots:
-criterion of at least 70% of vegetation lost focuses on cumulative past loss, not current rate of
lost
-does not include places like the Amazon
-hotspots focus on species not ecosystem diversity
Major threats to biodiversity
-habitat destruction and degradation
-invasive species and disease
-overexploitation
-pollution
-climate change
Phylogenetic Analysis
How can we study the history of life?
Phylogeny→ the evolutionary history of a group of organisms
Two major analytical tools to reconstruct the history of life:
1.the fossil record
2.Phylogenetic trees
→ can be used separately or in combination
-Phylogenetic tree:graphical summary of this history
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anyiamgeorge19. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83637 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now