Variation and Adaption Flashcards
This is the difference among members of the same species or organisms of the same type
Variation
What are the 2 types of Variation?
Continuous and Discontinuous
What is Continous Variation?
Complete range of measurements or range of values from extreme to another ( ex. height )
What is Discontinuous Variation?
Characteristics fall into a number of distinct classes or categories
Are all variations genetic?
No, Variation may also be “adaptive” due to environmental effects or an individual’s action. They cannot be passed down to another offspring (non-inheritable variation)
What are adaptive features?
These are specific traits that anables individuals to survive in a particular environement
How do organisms acquire adaptive features?
They adapt these by the selection pressures that they are faced with. These selection pressures may be the arrival of a new predator or the change in weather conditions.
What is natural selection (Charles Darwin) ?
This is the process which a population becomes adapted to its environment
What are the causes of Variation?
- Mutation
- Sexual Reproduction (Meiosis)
- Fertilisation
- Environment
How is Mutation a cause of Variation?
During the Process of Mutation, there is change in the base sequence in the DNA. With that, new alleles are created. Thus variation.
How is Sexual Reproduction a cause of Variation?
During the process of meiosis and mate selection may result in unique combinations of alleles
How is Fertilisation a cause of Variation?
The unique combination of alleles in sperm and ova leads to the offspring to have a unique combination of alleles (genotype) and phenotype (Appearance)
How exactly is Meiosis a cause of variation?
This is through the Crossing Over and independent assortment stages during the process of meiosis
Some more info
Mutations can potentially change the phenotype of an individual by altering the genotype
What happens during the Crossing Over process?
○ Homologous chromosomes pair up
○ Parts of neighbouring chromosomes pair up
○ Crossed over sections of chromosomes are exchanged
○ Each gamete produced may have different combinations of alleles
