genetic diversity and adaption Flashcards
what is genetic diversity?
the total number of genetic characteristics in the genetic make up of a species.
what are alleles and how do they arise?
variations of a particular gene with a difference DNA base sequence which arise by mutation
what is a population?
a group of interbreeding individuals of the same species
explain the importance of genetic diversity
-enables natural selection to occur
-New allele may benefit possessor giving a selective advantage (increased chances of survival)
what is evolution?
change in allele frequency over many generations in a population occurring through the process of natural selection
exain the principles of natural selection in the evolution of populations
mutations produce new alleles of a gene, organisms would have a selective advantage and are more likely to survive and have an increased reproductive success. These advantageous allele is inherited by members of the next generations (offspring) and over generations alleles increase in frequency in the population
describe the 3 types of adaptions
Anatomical- physical features which increase chance of survival
Physiological- chemical reactions that increase chance of survival
Behavioural- ways in which an organism acts that increase chance of survival
what is directional selection?
environmental conditions change and the phenotypes best suited for the conditions are more likely to survive.
what is stabilising selection?
successful characteristics are perserved and those of greater diversity are reduced, does not occur due to changes to the environment
What is the significance of genetic diversity?
Varitation is nessisary for adaption and survival.
-large polpulations have a greater allele diversity
What is the quasion for Allele frequence?
the number of a species type of allele/ the total number of alleles in the gene pool
Describe darwins theory of evolution?
Individual with better adaptions to their enviroment compete better than others, to survive longer and reproduce more and so pass on their succsessful genes to the next generation
What is a gene pool?
within a population of a species their s a wide variety of alleles
What is disruptive (diverging) selection?
When both extremities of phenotypes are selected over intermediate types
draw a directional selection graph.
