Module 3 - Biodiversity And Evolution Flashcards
(42 cards)
What is biodiversity? Is it only viewed at one level?
Biodiversity is the range of organisms. It can be considered at many levels - in a habitat, between species and in genetic variation within a species.
Why do we sample organisms?
- quicker than counting all organisms
- gives representation of a whole habitat
How do we ensure that a sample takes place at random?
- use a random number table
OR - take samples at regular distances
In what ways do we sample plants?
1) random quadrats: quadrat placed at random. Abundance is measured by either % cover (by counting the squares) or by using a point frame.
2) transect: line taken across a habitat, record plants touching line at set intervals
What are three ways of sampling animals?
1) sweep netting: sweeping a net through an area. Any organisms caught are put on a white sheet and counted.
2) collecting from trees: white sheet is placed under branch while branch is shaken so any animals fall onto the sheet.
3) pitfall trap: container buried just under surface of soil. Any animals moving through plants will fall into container.
Define ‘species richness’
Species richness: number of species in a habitat
Define ‘species evenness’
Species evenness: relative abundance of individuals in each species.
How can species evenness be calculated in animals?
Total population = (C1 x C2) / C3
C1 -> first sample of animals
C2 -> second sample
C3 -> already marked animals caught on 2nd sample
Why is the simpson’s diversity index good?
It’s good because it takes into account both richness and evenness.
What does a high diversity index value indicate?
Diverse habitat, stable, can withstand change.
What does a low diversity index value indicate?
Few species. Small changes could damage/destroy the habitat.
Define ‘taxonomy’
Taxonomy - the study of classification
Define classification
The grouping of living organisms according to shared similarities
Define phylogeny
The study of evolutionary relationships between organisms
describe the classification of species into
the taxonomic hierarchy
- kingdoms are sorted into domains
- phyla are sorted into kingdoms
- classes are sorted into phyla
- orders are sorted into classes
- families are sorted into orders
- genus are sorted into families
- species are sorted into genus
What are the five kingdoms?
Prokaryotes, protoctists, fungi, animals, plants
Describe the characteristics of prokaryotes
- no nucleus
- no membrane bound organelles
- smaller ribosomes
- respiration in mesomes
Describe the characteristics of protoctists
- eukaryotes
- mostly single called but some multi cellular
- autotrophic and heterotrophic
- basically everything that doesn’t fit into any other group
Describe the characteristics of fungi
- eukaryotes
- walls made of chitin
- saprophytic
Describe the characteristics of animals
- eukaryotes
- heterotrophic
Describe the characteristics of plants
- eukaryotes
- autotrophic
- cellulose cell wall
- permanent vacuole
What does saprophytic, autotrophic and heterotrophic mean?
Saprophytic: nutrition by decaying organic matter
Autotrophic: nutrition by photosynthesis
Hetereotrophic: nutrition by digesting organic matter
What system is used to name each species?
The binomial system. Two names in Latin - the genus name and the species name.
What is the dichotomous key?
The dichotomous key is a series of questions with alternate answers to help you identify a specimen. each question has a yes or no option.
