10.5 Flashcards
What is variations?
Differences in characteristics between members of different organisms
What is interspecific variation?
differences in characteristics between members of different species
What is intraspecific variation?
Differences between organisms within a species
What are causes of variation?
- organisms genetic material- differences in the genetic material an organism inherits from its parents is genetic variation. Individuals of the same species have the same genes but different versions called alleles- the difference in geneotype results in variation in phenotype
- The environment in which the organism lives- environmental variation
- Or both- like height.
What are genetic causes of variations?
- alleles- genes have different alleles
- Mutations- changes in the DNA sequence changes the proteins that are being coded for affecting the phenotype of an organism. If the mutation occurs in the somatic cells, the individual is only affected but if it occurs in the gametes then it may be passed onto offspring.
- Meiosis- gametes are produced by the process of meiosis in organisms that reproduce sexually. The genetic material is mixed up by independent assortment and crossing over.
- Sexual reproduction- offspring inherit genes from each of the parents
- Chance-
What are the environmental causes of variation?
- plants grown where it has greater access to sun would grow larger than one that doesn’t as it has more light for photosynthesis
- In animals, it may be scars on your body as they cannot be inherited
What is continuous or discontinuous variation?
Variation can be continuous (individuals within a population can be within a range- there are no distinct categories)
Continuous variation produces a histogram with a bell shaped curve
or discontinuous (they fall within categories) so we can use a bar chart