Does anyone know the answer to any of these, please feel free to answer more than 1 question please

How does a gymnosperm prevent itself from pollinating the same tree

In a vegetable garden 45 bean plants have been eaten by deer 5 are untouched what is the frequency of bean plants in the garden that have been eaten?

Astudy by solloch and et. al., in 2017, gives the map above which shows the frequency of alleles with a ccr5-delta32 mutations over 87 different countries. this mutation deletes the presence of a co-receptor (ccr5) on the outside of human t-cells (lymphocytes). some viruses, such as the one responsible for the black death and human immunodeficiency virus (hiv), require this receptor for attachment to host cells during the infection process. the black death was an epidemic that passed over northern europe during the 14th century killing nearly 60% of europeans. according to this information, which explanation best explains why northern europeans show a greater immunity for hiv than some other parts of the world?