Variation within phenotypes Flashcards
What factors are variation due to?
Variation is due to genetic and environmental factors
What are mutations?
Mutations are the sudden changes to genes and chromosomes that may, or may not, be passed onto the next generations
What are the three things that genetic variations are the result of?
Genetic variations are the result of mutations, meiosis and the random fertilisation of gametes
What are meiosis?
Meiosis is a form of nuclear division that produces new combinations of alleles before they are passed into gametes, producing different gametes
What is the random fertilisation of gametes?
The random fertilisation of gametes produces new combinations of alleles therefore resulting in offspring that are different from parents
What are some environmental influences that affect variation within genotypes?
Environmental influences include climatic conditions (temperature, rainfall and sunlight), soil conditions, pH and food availability
What is discontinuous variation?
This is where variation is largely the result of genetic factors so organisms fit into a few distinct forms and there are no intermediate types
How is variation affected by the environment?
Genes set limits but largely it is the environment that determines where, within the limits, an organism lies
What are the two categories variation within phenotypes can be categorised into?
Variation within phenotypes can be categorised into:
1) continuous - quantitative differences of phenotypes where there is a wide range of differences
2) discontinuous - qualitative differences of phenotypes where there is no intermediate category
Are these continuous or discontinuous variations in phenotypes?
1) Eye colour
2) Height
3) Weight
4) Egg laying by hens
5) Egg sizes in hens
6) Blood group
7) Gender
1) Eye colour (D)
2) Height (C)
3) Weight (C)
4) Egg laying by hens (D)
5) Egg sizes in hens (C)
6) Blood group (D)
7) Gender (D)
