Types of Variation
This type of variation shows a range of phenotypes between two extremes.
continuous variation
This is a genetic change that introduces new alleles into a population.
mutation?
An inherited feature that helps an organism survive and reproduce.
adaptive feature
This type of selection occurs without human interference and results in better adaptation over generations.
natural selection
This type of variation shows a limited number of phenotypes with no intermediates.
discontinuous variation
These environmental factors increase the rate of mutation.
ionising radiation and certain chemicals
Hydrophytes and xerophytes are adapted to these types of environments.
aquatic and dry (arid) environments
This type of selection involves humans choosing individuals with desirable traits to breed.
artificial selection or selective breeding
Examples of this type of variation include height and body mass.
continuous variation
A random change in the base sequence of DNA is known as this.
gene mutation
The process by which populations become more suited to their environment over time.
adaptation (through natural selection)
Natural selection includes struggle for survival and competition for this.
resources
Examples of this type of variation include ABO blood groups and pea seed shape.
discontinuous variation?
Mutation, meiosis, random mating, and this process are all sources of genetic variation. what other?
random fertilisation?
The broad-leaf surface of a water lily is an example of this kind of plant adaptation.
hydrophyte adaptation
These organisms are more likely to survive and pass on their alleles.
individuals better adapted to the environment
This kind of variation is usually caused by both genes and the environment.
continuous variation?
New alleles are formed through this process.
mutation
A thick cuticle and sunken stomata help xerophytes reduce this.
water loss (or transpiration)
The rise of antibiotic-resistant bacteria is an example of this process in action.
natural selection