Topic 4A - Biodiversity Flashcards
EQ. Describe what is meant by biodiversity (2 marks)
- the variety of species within a habitat
- the variety of alleles in a population
Define endemic
a species that’s only found in one geographical location
EQ. Suggest how natural selection could have given rise to certain adaptations (5 marks)
- selection pressures creates a struggle for survival
- such as predation
- mutations introduce new alleles into the population
- individuals with advantageous alleles are more likely to survive
- and therefore pass on advantageous alleles to their offspring
- so there will be an increased frequency of advantageous alleles in the population
EQ. Explain how two species of African elephant could evolve from a common ancestor. (3 marks)
- when 2 populations are geographically isolated from each other
- they experience different selection pressures so they develop different adaptations
- and there is a reduced gene flow between the 2 populations
- this leads to allopatric speciation
Define species
organisms that can interbreed to produce fertile offspring.
What is the hierarchy of taxonomy?
Domain Kingdom Phylum Class Order Family Genus Species (Dumb King Phillip Came Over From Great Spain)
What are the five kingdoms?
Animalia Plantae Fungi Protoctista Prokaroytae.
To which group do fungi belong?
eukaryota
Define species richness
the number of different species in an area
Define population size
the number of individuals per species
EQ. Eukarya is one of the three domains. Name the other two domains. (2 marks)
- archaea
- bacteria
EQ. Scientists classify organisms into taxonomic groups, such as the three domains. Explain how organisms can be classified into taxonomic groups. (2 marks)
- organisms with similar characteristics are placed in the same group
- characteristics like behavioral similarities and molecular phylogeny
EQ. Woese suggested that organisms could be placed in taxonomic groups based on molecular phylogeny. Explain what is meant by this statement. (4 marks)
- organisms with similar charactersitics are placed in the same group
- each taxonomic group have specific differences
- molecular phylogeny looks at the similarities in the DNA sequence
- and shows the evolutionary relationship through genetics
Define niche
the position occupied by an organism in its ecosystem
EQ. Explain what is meant by the term niche, using the plant Epilobium latifolium as an example. (3 marks)
- niche is the role of epilobium latifolium within its ecosystem
- epilobium latifolium is a producer
- and provides energy for primary consumers
- and adds nutrients and humus to the soil
EQ. Describe how to carry out a study of the distribution of Epilobium latifolium from the front edge of this glacier. (4 marks)
- take a transect along a line from the front edge of this glacier
- place quatrats
- at regular intervals of 10m
- estimate percentage cover by counting the number of squares covered by epilobium latifolium
EQ. Suggest one abiotic factor that might affect the abundance of Epilobium latifolium and describe how this factor could be measured. (4 marks)
- water content may be a factor
- take a soil sample around the roots
- weigh soil samples before and after drying it (until you find a constant mass) and find difference
- take multiple readings and find average
Describe the difference between biodiversity within a species and biodiversity within a habitat.
biodiversity within a species is the variety of alleles within a species and biodiversity within a habitat is the variety of species within a habitat
EQ. A pond had a low index of diversity. Explain how the composition of this community could have resulted in this low index of diversity (2 marks)
- low species richness which lowers N
- some species may be abundant while other species are few which lowers n
Woese suggested that there are three domains based on evidence from…
molecular phylogeny
The 2 domains that contain prokaryotic cells are…
archaea and bacteria
EQ. Herbicides are sprayed on a lawn to kill unwanted plants. Explain how the index of diversity would change. (2 marks)
- index of diversity would decrease
- because there will be fewer species present
EQ. Explain what is meant by the term molecular phylogeny. (3 marks)
- looking at molecular similarities and differences
- in the DNA
- used to see the evolutionary relationships between organisms
EQ. Describe the 3 types of adaptations and an example for each. (3 marks)
- behavioural is the way an organism acts e.g scorpions dance to increase the chance to successful mating
- physiological is the chemical processes e.g brown bears hibernate by slowing their metabolism
- anatomical is the structural features e.g otters have a streamline shape so they can swim faster in water
Define phylogeny
the evolutionary relationships
What 2 things does the index of diversity take into account?
species richness and abundance
EQ. Explain how the primary structure of trypsin molecules can be used to produce a phylogenetic tree. (3 marks)
- we should determine the primary structure
- we find similarities or differences in the primary structure
- the more similar the primary structure the more closely related they are
EQ. Describe what needs to be measured in order to compare the biodiversity of 2 rainforests. (2 marks)
- measure species richness
- determine population size
