3.4.3 Biodiversity Flashcards
What is biodiversity?
The variety of living organisms in an area. includes species diversity and genetic diversity
What is species diversity
The number of different species and the abundance of each species in an area
What is genetic diversity?
The variation of alleles in the gene pool of a species
How is species richness counted?
counting the number of species in a known area using a quadrat
Why does biodiversity need to maintained?
loss of biodiversity means there are fewer species. Loss of endemic species leads to extinction. Some species have not yet been discovered that may be useful
Why is little genetic diversity bad?
no selective advantage when the environment changes, less likely to survive, so this increases risk of extinction
Why is increased genetic diversity advantageous for a species?
Greater chance of survival as higher chance of having beneficial alleles
Define species richness
The number of different species
Define ‘niche’
The role of a species within its habitat. It includes its interactions with other living organisms (biotic) and its interactions with the non living (abiotic) environment
What is a species?
A group of similar organisms that can reproduce to give fertile offspring
What does taxonomy involve?
naming organisms and organising them into groups based on their similarities and differences. This makes it easier for scientists to identify them and study them
Why are species in the same genus separate species?
because they cannot breed successfully to produce fertile offspring
What is the binomial system?
first word is the genus name and the second word is the species name.
Why is important that species are given a scientific name?
enables scientists to communicate about organisms in a standard way that minimises confusion
What are the five kingdoms?
prokaryote, protoctista, fungi, plants and animals
What is an example and features of prokaryote?
Bacteria, unicellular, no nucleus,
What is an example and features of protoctista?
algae, eukaryotic cells, live in water, single celled or simple multicellular organisms
What is an example and features of fungi?
moulds, eukaryotic, chitin cell wall, saprotrophic
What is an example and features of plants?
mosses, eukaryotic, multicellular, cellulose cell walls, autotrophic
What is an example and features of animals?
mammals, eukaryotic, multicellular, no cell walls, heterotrophic
What does phylogeny tell you?
which species have common ancestors with which and how recently they shared common ancestors
How does the new three domain system classify organisms?
all organisms are placed into one of three domains which are above the kingdoms in the taxonomic hierarchy. The three domains are bacteria, archaea and eukaryote
Why is a sample of a population taken instead of counting all individuals ?
it is too time consuming to count every individual organism in a habitat. estimates about the whole habitat are based on the sample
When is a quadrat used?
To sample populations of immobile organisms (e.g. plants)
What does sampling involve?
choosing an area to sample. the sample should be random to avoid bias, use a random number generator to select coordinates for a grid, count the number of individuals of each species in the sample area, repeat the process as it gives a better indication of the whole habitat,
What do related organisms have (how can we prove they are related using phylogenetic analysis) ?
similar DNA sequences and so similar amino acid sequences in their proteins
Why is courtship behaviour important for the survival of species? Give 4 reasons.
Helps to recognise members of own species, synchronise matins, recognise those able to breed, form a pair bond, become able to breed
How do you calculate index of diversity?
total number of all species(N). Total number of each species (n). N(N-1) / Sum of n(n-1)
Give three ways of comparing similarity of different species
compare observable characteristics, compare DNA base sequences, compare amino acid sequences
Define mean, mode and median
mean = average, mode = most occuring, median = middle value
Can you list 4 different ways of sampling?
what is a line transect good for?
what do these stand for
