Section 4 - Unit 10: Biodiversity Flashcards
Explain what is meant by a phylogenetic group (1 mark)
- Grouped according to evolutionary links / common ancestry
Explain what is meant by a species (2 mark)
- Able to reproduce
- To produce a fertile offspring
Suggest one source in which DNA could be obtained for scientific experiments (1 mark)
- Bone
- Skin
- Preserved remains
Other than hunting, suggest two reasons why populations might show very low levels of genetic diversity (2 marks)
- Population might have been very small
- Population might have started with small number of individuals
- Inbreeding
Define genetic diversity (1 mark)
Number of different alleles of each gene
Give three ways in which courtship behaviour increases the probability of successful mating (3 marks)
- Recognise/attract same species
- Stimulates production of gametes
- Recognise/attract mate of opposite sex
- Indication of fertility / readiness to mate
- Formation of a pair bond / bond between two organisms
What is meant by a hierarchy? (2 marks)
- Groups within groups
- No overlap
Explain the role of independent segregation in meiosis (2 marks)
- To provide genetic variation
- Allows different combinations of maternal and paternal chromosomes/ alleles
Explain why clearing a forest could decrease the species diversity in that area (3 marks)
- Decrease in variety of plants
- Fewer habitats/niches
- Decrease in variety of food / fewer food sources
State the order of the classification system (2 marks)
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
Explain how standard deviation can help interpret data (2 marks)
- Shows the spread of the data
- Overlap = no difference / due to chance / not significant
Explain the principles which biologists use to classify organisms into groups (3 marks)
- Large groups are divided into smaller groups
- Members of a group have features in common based on anatomy / fossils / DNA / specific aspects of cell biology
- Reflects evolutionary history
Explain what is meant when two species are described as being closely related (1 mark)
- More recent common ancestor/ DNA in common
A difference in the molecular structure of cytochrome c may arise in a small population that becomes geographically isolated. Explain how the difference may
arise and how it may spread in the population (4 mark)
- Mutation
- There is variation
- Genes (coding) for protein / cytochrome c with different structures
- Individuals with a modified cytochrome c have a selective advantage / these individuals are more likely to survive to have offspring
- Gene / allele frequency changes over generations / time
State the principles of classification (3)
- Species arranged into groups according to:
- evolutionary origin
- common ancestors
- relationships
