A3.1 Diversity of organisms HL Flashcards
A tool used in fieldwork for identifying organisms.
Dichotomous Key
Typically involves a series of questions based on organisms’ physical characteristics.
True or False: DNA barcoding is used for identifying species.
True
Involves comparing an unknown specimen’s unique DNA sequence to a catalogue of known sequences.
What is the main purpose of DNA barcoding in environmental studies?
To identify species and measure biodiversity
Useful for detecting elusive or endangered species without direct observation
Fill in the blank: A dichotomous key is composed of a series of questions with ____ possible answers.
Two
Describe one use of DNA barcoding outside environmental assessments
Testing food for microorganism contamination
Also used for identifying life cycle stages and analyzing diet through stomach contents
True or False: DNA barcoding shows more variation within species than between them.
False
It’s selected for its high variation between species
What is the first step in developing a dichotomous key?
Split organisms into two groups based on a characteristic
Continues with further bifurcations until individual species are identified
Identify the process: Extracting DNA from environmental samples to create a unique species ‘barcode’.
DNA Barcoding
How does a dichotomous key assist in species identification?
Through a series of binary choices based on physical characteristics
Simplifies the process of differentiating between similar species.
Fill in the blank: DNA barcoding is significant for tracking _______ species.
Endangered
Define ‘Biodiversity’.
The variety of life in the world or a particular habitat.
A key indicator of ecosystem health.
True or False: Dichotomous keys are only useful for identifying plants.
False
They are versatile tools used for identifying various organisms.
What characteristic of DNA sequences is crucial for DNA barcoding?
High variation between species.
This trait allows for accurate species identification
Describe one challenge in using DNA barcoding for species identification.
Requires a comprehensive catalogue of DNA barcodes for comparison
Incomplete catalogues may lead to misidentification
How does biodiversity contribute to ecosystem health?
Provides resilience and adaptability to environmental changes
Diverse ecosystems are better equipped to withstand disturbances.
