Variation Flashcards
What is meant by variation within a species?
this refers to the differences in appearance among individuals in the same species
what causes genetic variation within a population?
it is caused by differences in a genotype which includes all of an organisms genes and alleles
What is genotype, and how does it relate to phenotype?
Genotype is an organism’s genetic makeup, which affects its phenotype (the observable characteristics)
Besides genotype, what else can influence an organism’s phenotype?
an organism’s phenotype can be influenced by interactions with its environment
Give an example of environmental variation influencing phenotype.
a plant grown in sunlight versus darkness will display different characteristics.
Provide an example of how genetic and environmental factors interact to determine phenotype:
The maximum height potential of an animal or plant is determined by its genes, but whether it actually reaches that height depends on environmental factors such as nutrition
What is a mutation?
A rare, random change in an organism’s DNA that can be inherited.
What does a mutation result in?
A genetic variant (a different form of the gene)
How do gene mutations sometimes affect proteins?
-They may lead to changes in the protein that the gene codes for
-Most have very little or no effect on the protein’s function meaning most mutations have no effect in the organism’s phenotype
Give an example of a genetic variant influencing phenotype
Eye color, controlled by multiple genes, can be slightly altered by mutations in one of these genes
Provide an example of a genetic disorder caused by a mutation.
Cystic fibrosis, caused by a gene mutation affecting a protein that regulates salt and water movement, leading to excess mucus production in the lungs and digestive system.
