genetic diversity and adaptation Flashcards
1
Q
What is genetic diversity?
A
The range of genes and alleles within a population in a particular area
2
Q
Ecosystem Diversity
A
The range of habitats within a particular area
3
Q
What is a population?
A
Population > group of interbreeding individuals of the same species
4
Q
What is natural selection? [5]
A
- Variation of alleles exists in population due to random DNA mutations
- Selection pressure / change in environment
- Those with advantageous allele have increased chance of survival and reproductive success
- Those surviving and reproducing pass advantageous allele to offspring
- Frequency of advantageous allele and (named) characteristic increases in the population over many generations
5
Q
What was Darwin’s Theory of Evolution?
A
Evolution by natural selection
6
Q
What was Lamarck’s Theory of Evolution?
A
Changes that occur within an organism’s lifetime are passed on to offspring
e.g.
a giraffe would stretch its entire life to have a slightly longer neck, it would then reproduce and pass this trait onto its offspring
7
Q
Directional selection [4]
A
- Change to the environment
- Selection pressure favours one extreme
- One extreme phenotype more likely to survive and have reproductive success
- Mean phenotype in population changes
(curve remains same shape but shifts in one direction)
8
Q
Stabilising selection [4]
A
- Stable environment
- Selection pressure acts either side of the mean
- Both extremes of phenotype less likely to survive and have reproductive success
- Mean phenotype remains the same
(curve becomes more centred)
