Variation IGCSE Biology

Variation

Differences shown by organisms within the same species

Types of variation

Continuous and Discontinuous

Continuous Variation graph

Histogram

discontinuous variation graph

Bar graph

continuous variation

Variation that can take any range and has intermidiates in phenotypes

discontinuous variation

It is determined by genes only and has no intermidiates

variation leads to

Evolution of a new organism or species

mutation

A sudden or spontaneous changes happening to the genetic makeup of an organisms

mutation leads to

origin of a new organism

types of mutation

genetic and chromosomal

example of a mutation for blood called

Sickle-cell anaemia

advantage of sickle cell anaemia

Can never suffer from malaria

what causes mutation

Radiation and chemicals

adaptive feature

An inherited feature that helps you to survive and reproduce

Natural selection

Genetic variation within a population

artificial selection

choosing the advantageous alleles

what traits do selective breeding in crops prefer

drought resistant, pest resistant, traits that encourage growth

what traits do selective breeding in animals prefer

high milk yield, good quality meat