Produces different proteins and therefore different structures and effects
Blood group
Mutations
Mistake in DNA
Changes in protein that are coded for
Cystic fibrosis
Meiosis
Gametes form which have half the genetic material of parent cells. Crossing over and independent assortment also occur to make every gamete genetically different.
Different gametes have different mix of alleles
Variation in gametes
Sexual reproduction
Inherit genes from both parents
Individual produced is genetically different from parents
Children
Chance
Chance which gametes fertilise
Unique combination of genetic material for each offspring
Siblings different from each other
Environmental Causes of Variation
Environmental cause of variation
What happens?
Why does it cause variation?
Example?
Conditions for plant
Plants in different conditions grow to different sizes Plants in different pH soils can grow different coloured flowers Lack of nutrients for plant
More sunlight for photosynthesis to make glucose for respiration and growth Acidic soil makes blue flowers. Alkali makes pink flowers Proteins
Rose bush in higher light intensity grows bigger Different coloured flowers of hydrangeas Nitrates
Injury/Disease
Damaged tissue
Damages cell, leaves marks on skin
Scars
Combined Environmental and Genetic Causes of Variation
Environmental and genetic effect of variation
How do genetics play a part?
How does environment play a part?
Height
Inherited genes from parents
Malnourishment
Skin colour
Genes instruct melanin levels
Sunlight can increase melanin production
Discrete Variation
Discontinuous/discrete variation is normally only controlled by a single gene (or very few).
There are no in-between values, only specific ones.
Normally represented through a bar chart.
Continuous variation
A characteristic that can take any value in a range (quantitative) is said to show continuous variation.
Characteristics that show continuous variation such as height show a normal distribution pattern
These characteristics are usually controlled by a number of genes (polygenic) and influenced by the environment