Biodiveristy And Classification Flashcards
What is a species?
- group of similar organisms
- that can reproduce to produce fertile offspring
Explain what is meant by a hierarchy.
- groups within groups
- no overlap between groups
Explain what is meant by a phylogenetic group.
- grouped according to evolutionary links
Describe how organisms are grouped in a phylogenetic classification system.
- hierarchy of groups with no overlaps
- grouped according to evolutionary origins
Explain what is meant by genetic diversity.
- difference in DNA base sequence
Explain why an index of diversity may be a more useful measure of biodiversity.
- measures number of individuals in a species
- some species may be present in low/high numbers
What is meant by species richness.
- number of different species in a community
Explain how natural selection produces changes in a species.
- variation caused by mutation
- competition results in differential survival
- some have adaptations that favour survival
- differential reproductive success
- pass on their advantageous alleles
- changes alleles frequency
Describe how comparisons of biological molecules in two species could be used to find out if they are closely related.
- genetic variation
- compare DNA base sequence
- compare RNA base sequence
- compare sequence of amino acids
- DNA hybridisation by separating DNA strands
- mix DNA strands
- heat required to separate hybrid strands, indicates relationship
- inject protein in animal
- obtain antibodies
- add protein from other species
- amount of precipitate indicates relationship
Why does comparing the base sequence of a gene give more information than comparing the amino acid base sequence?
- longer base sequence than amino acid sequence
- introns
- code may be degenerate
Describe the processes that leads to a reduction in the genetic diversity of populations of organisms.
- reduced gene pool in new generation
- founder effect
- a few individuals from a population become isolated
- genetic bottlenecks
- significant fall in size of population
- selective breeding
- using organisms with particular alleles
How can scientists use protein structure to investigate the evolutionary relationships between different species.
- amino acid sequence
- closer the amino acids sequence, the closer the relationship
- protein structure related to DNA base sequence
Why does the clearing of a forest decrease the species diversity of the area?
- decrease in variety of plants
- fewer habitats
- decrease in variety of food
- killing insects/ introducing pesticides
What is meant by a genetic bottleneck?
- sudden decrease in population
= reduced genetic variation
Ethical arguments for maintaining biodiversity.
- prevent extinction
- save organisms for future generations
