See how inherited germ-line mutations add new alleles and how meiosis and random fertilisation reshape existing alleles into new combinations.
Explain how sexual reproduction can eventually lead to evolution in offspring.
offspring vary in traits;
variation results from sexual reproduction;
independent assortment of alleles (during meiosis of spermatogenesis/ oogenesis) contributes to variation;
meiosis is the cellular process that produces gametes;
crossing over (during meiosis) increases variation;
fertilization (combination of different genomes) contributes to variation;
more offspring may be produced than the environment can hold;
struggle for existence can occur;
offspring whose traits best adapt them to environment will survive/survival of fittest;
change in environment will lead to survivors with new/different traits;
correct use of term natural selection/selective pressure;
variation is heritable / over time more offspring born with new trait;
change in gene pool;
when entire population (of a species) exhibits new trait, evolution has occurred;