Diversity, Variation & Classification Flashcards
What are the two types of variation?
- Continuous
- Discontinuous
Give two causes of variation.
- Genetic differences
- Environmental factors
Give three ways through which genetic variation arises.
- Mutations
- Meiosis (independent segregation & crossing-over)
- Fusion of gametes
Give six environmental factors that can influence variation.
- Temperature
- Rainfall
- Light intensity
- Soil conditions
- pH
- Food availabilty
Why are identical twins used in some studies?
The are genetically identical so differences are due to environmental factors.
OR
They show genetic influences
(if both twins have a condition it suggests there is some genetic influence)
Why are non-identical twins used in some studies?
They show environmental influences
(they have different genes so any similarities are due to their environment)
What is meant by genetic diversity?
Differences in alleles
State three processes which cause a decrease in genetic diversity.
- Founder effect
- Genetic bottleneck
- Selective breeding
Define: a species
A group of similar organisms that are called of interbreeding to produce fertile offspring.
How are species named?
Generic name (genus) then specific name (species)
Define: phylogenic relationship
The evolutionary relationship between organisms
What are the groups in the hierarchy system?
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is meant by a hierarchal system?
Smaller groups within larger groups with no overlap
