Variation and Selection Flashcards
What is selection pressure?
A condition in an environment that affects the chances of individuals with different features to reproduce.
i.e. predators.
What is an adaptation?
The process by which populations become more suited to their environment over many generations.
Caused by natural selection
What are the four main causes of genetic variation?
Mutation, Meiosis, Random Mating, Random Fertilisation
What is the main cause of mutations?
Ionising Radiation
What are hydrophytes and xerophytes?
Plant classifications
Hydro - adapted to live in / around water
Xero - adapted to survive in dry environments
What are some adaptations of hydrophytes?
Wide flat leaves with a high surface area to float and absorb more sunlight for photosynthesis
Small roots (They can absorb water through leaves and stems)
Stomata on upper side for efficient gas exchange
What are some adaptations of xerophytes?
Thick waxy cuticle and sunken stomata reduce water loss
Small leaves to reduce surface area for evaporation.
